Abstract

The self is, at least partially, grounded in bodily processing. In particular, processing the physiological state of the body (i.e., interoception) plays a key role in self‐consciousness and the first‐person experience. The present study examined cultural differences in interoceptive processing. We focused on a behavioral measure of cardiac processing, which was assessed using a heartbeat‐counting task; namely, interoceptive accuracy (IAcc). Study 1 compared IAcc scores that were previously collected in Japan and the United Kingdom and found no statistically significant differences between the cultures. Study 2 was conducted in a more elaborate manner; that is, we collected new data on IAcc from Japanese students using better‐adapted task instructions, as well as possible confounds that influence IAcc (i.e., time estimation, knowledge of heart rate, and actual heart rate). We compared these data with those collected from Belgian students and found that the Japanese participants detected heartbeats more accurately than did the Europeans. The results are discussed from the perspective of cultural differences in objective self‐awareness, and a self‐flexibility and a bodily precision account of IAcc.

Introduction

Adults possess a natural inclination to associate sensory cues derived from distinct modalities, such as the pairing of sweet with pink. However, studies exploring crossmodal correspondences in children, particularly in the sensory pairing of visual features and tastes, are scant, leaving unanswered questions regarding the developmental trajectory of crossmodal correspondences. The present study investigates whether Japanese preschool children demonstrate specific biases in shape–color, shape–taste, and color–taste associations.

Methods

In a series of in-person experiments, 92 children between 3 to 6 years of age completed matching tasks utilizing paper stimuli.

Results

Children exhibit crossmodal correspondences in shape-color (circle-red and asymmetrical star-yellow), shape–taste (triangle-salty and circle-sweet), and color–taste (yellow-sour, black-bitter, and pink-sweet) associations. Moreover, children’s choices are not influenced by their individual preferences.

Discussion

The crossmodal correspondences observed in this study have been observed in previous research on adults from the same (Japanese) culture, although adults showed more crossmodal correspondences than the children in this study (e.g., pink-circle, triangle-sour, and green-bitter). Thus, while some crossmodal correspondences emerge during childhood, others may require additional time to develop, thereby highlighting the importance of understanding the cognitive mechanisms underlying crossmodal correspondences from an ontogenic perspective.

The subjective truth of a statement is boosted by mere exposure to itself or a part of itself. This phenomenon is referred to as the illusory truth effect . We examined whether subliminal pre-exposure to the statement topic would increase its subjective truth. In the exposure phase, participants observed the topic, which was presented supraliminally or subliminally. After the exposure phase, they rated the subjective truth of the statement. If unconscious processing contributed to the illusory truth effect, subliminal exposure to the topic would increase the subjective truth of the statement. On the other hand, if the illusory truth effect required conscious and controlled processing, increases in the subjective truth of a statement would be induced only by supraliminal exposure to the topic. The results showed that the illusory truth effect was not found in either supraliminal or subliminal groups. Our findings provide no reliable evidence that pre-exposure to the statement topic saliently promotes its subjective truth.

Abstract

Non-synesthetes exhibit a tendency to associate specific shapes with particular colors (i.e., circle–red, triangle–yellow, and square–blue). Such color–shape associations (CSAs) could potentially affect the feature binding of colors and shapes, thus resulting in people reporting more binding errors in the case of incongruent, rather than congruent, colored-shape pairs. Individuals with autism spectrum disorder (ASD) exhibit atypical sensory processing and impaired multisensory integration. Here, we examined whether autistic traits (Autism-Spectrum Quotient; AQ) influence the strength of color–shape associations, as evidenced by the occurrence of binding errors in incongruent minus congruent conditions. Participants took part in an experiment designed to reveal binding errors induced by incongruent and congruent colored-shape pairs, and completed the Japanese version of the AQ score. The results revealed a significant correlation between AQ scores and occurrence of binding errors when participants were presented with the circle–red and triangle–yellow CSAs: That is, individuals with higher autistic traits tend to make more binding errors in incongruent minus congruent colored-shape pairs, indicating a stronger binding of circle–red and triangle–yellow associations. These results therefore suggest that autistic traits play a role in forming color–shape associations, shedding light on the nature of both color–shape associations and autistic perception.

Non-synesthetes exhibit a tendency to associate specific shapes with particular colours (i.e., circle-red, triangle-yellow, and square-blue). Here, we used two Go/No-go tasks to examine the congruency priming effect of colour–shape associations on recognition efficiency of colour and shape features. At the beginning of each trial, a target colour or shape word was introduced, followed by a coloured-shape visual stimulus. Participants were required to press a key to a target stimulus (“go” cues), while withholding their responses to a non-target stimulus (“no-go” cues). The targets were presented either visually (visual word, Experiment 1) or auditorily (spoken word, Experiment 2). Results showed a congruency effect of colour–shape associations on recognition efficiency for colour and shape features in both experiments. Response times were shorter in congruent than in incongruent conditions, that a target could be recognised faster when it was presented with the congruent visual features than with incongruent ones, irrespective of the presentation form (visual or auditory). These results suggest that colour–shape associations can be strong to influence visual recognition of colour and shape features.

Two versions of the flash grab illusion were used to examine the relative contributions of motion before and motion after the test flash to the illusory position shift. The stimulus in the first two experiments was a square pattern that expanded and contracted with an outline square flashed each time the motion reversed producing a dramatic difference in perceived size between the two reversals. Experiment 1 showed a strong illusion when motion was present before and after the flashed tests or just after the flashes, but no significant effect when only the pre-flash motion was present. In Experiment 2, motion always followed the flash, and the duration of the pre-flash motion was varied. The results showed a significant increase in illusion strength with the duration of pre-flash motion and the effect of the pre-flash motion was almost 50% that of the post-flash motion. Finally, Experiment 3 tested the position shifts when the linear motion of a disk before the flash was orthogonal to its motion after the flash. Here, the results again showed that the pre-flash motion made a significant contribution, about 32% that of the post-flash motion. Several models are considered and even though all fail to some degree, they do offer insights into the nature of the illusion. Finally, we show that the empirical measure of the relative contribution of motion before and after the flash can be used to distinguish the mechanisms underlying different illusions.

Temporal expectations are essential for appropriately interacting with the environment, but they can be biased. This tendency, called central bias, places higher weights on expected rather than actual duration distributions when perceiving incoming sensory stimuli. In particular, the central bias is strengthened in order to decrease total response error when incoming sensory stimuli are unclear. In the present study, we investigated whether the central bias was enhanced via memory decay. For this, we used a delayed reproduction task, manipulating retention periods by introducing delays between the sample interval and the reproduction phase (0.4, 2, 4 s in Experiment 1; 0.4, 2, 8 s in Experiments 2 and 3). Through three experiments, we found the gradual strengthening of the central bias as a function of the retention period (i.e., short-term memory decay). This suggests that the integration of temporal expectation, generated from past trials and stored sensory stimuli, in a current trial occurs in the reproduction phase in the delayed reproduction task.

A novel stimulus embedded in a sequence of repeated stimuli is often perceived to be longer in duration. Studies have indicated the involvement of repetition suppression in this duration distortion, but it remains unclear which processing stages are important. The present study examined whether high-level visual category processing contributes to the oddball's duration distortion. In Experiment 1, we presented a novel face image in either human, monkey, or cat category after a repetition of an identical human face image in the temporal oddball paradigm. We found that the duration distortion of the last stimulus increased when the face changed across different categories, than when it changed within the same category. However, the effect of category change disappeared when globally scrambled and locally scrambled face images were used in Experiments 2 and 3, respectively, suggesting that the difference in duration distortion cannot be attributed to low-level visual properties of the images. Furthermore, in Experiment 4, we again used intact face images and found that category changes can influence the duration distortion even when a series of different human faces was presented before the last stimulus. These findings indicate that high-level visual category processing plays an important role in the duration distortion of oddballs. This study supports the idea that visual processing at higher visual stages is involved in duration perception. (219 words).

Verbal hints can bias perceptual decision-making, even when the information they provide is false. What makes individuals more or less susceptible to such influences, however, remains unclear. Here, we inquire whether suggestibility to social influence, a high-level trait measured by a standard suggestibility scale, could predict changes in perceptual judgments. We asked naive participants to indicate the dominant color in a series of stimuli after giving them a short, false verbal statement about which color would likely dominate. We found that this statement biased participants' perceptual judgments of the dominant color, as shown by a correlated shift of their discrimination performance, confidence judgments, and response times. Crucially, this effect was more pronounced in participants with higher levels of susceptibility to social influence. Together, these results indicate that social suggestibility can determine how much simple (albeit false) verbal hints influence perceptual judgments. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Reading the genuineness of facial expressions is important for increasing the credibility of information conveyed by faces. However, it remains unclear which spatio-temporal characteristics of facial movements serve as critical cues to the perceived genuineness of facial expressions. This study focused on observable spatio-temporal differences between perceived-as-genuine and deliberate expressions of happiness and anger expressions. In this experiment, 89 Japanese participants were asked to judge the perceived genuineness of faces in videos showing happiness or anger expressions. To identify diagnostic facial cues to the perceived genuineness of the facial expressions, we analyzed a total of 128 face videos using an automated facial action detection system; thereby, moment-to-moment activations in facial action units were annotated, and nonnegative matrix factorization extracted sparse and meaningful components from all action units data. The results showed that genuineness judgments reduced when more spatial patterns were observed in facial expressions. As for the temporal features, the perceived-as-deliberate expressions of happiness generally had faster onsets to the peak than the perceived-as-genuine expressions of happiness. Moreover, opening the mouth negatively contributed to the perceived-as-genuine expressions, irrespective of the type of facial expressions. These findings provide the first evidence for dynamic facial cues to the perceived genuineness of happiness and anger expressions.

People are typically faster to categorize the race of a face if it belongs to a race different from their own. This Other Race Categorization Advantage (ORCA) is thought to reflect an enhanced sensitivity to the visual race signals of other race faces, leading to faster response times. The current study investigated this sensitivity in a cross-cultural sample of Swiss and Japanese observers with a race categorization task using faces that had been parametrically degraded of visual structure, with normalized luminance and contrast. While Swiss observers exhibited an increasingly strong ORCA in both reaction time and accuracy as the face images were visually degraded up to 20% structural coherence, the Japanese observers manifested this pattern most distinctly when the faces were fully structurally-intact. Critically, for both observer groups, there was a clear accuracy effect at the 20% structural coherence level, indicating that the enhanced sensitivity to other race visual signals persists in significantly degraded stimuli. These results suggest that different cultural groups may rely on and extract distinct types of visual race signals during categorization, which may depend on the available visual information. Nevertheless, heavily degraded stimuli specifically favor the perception of other race faces, indicating that the visual system is tuned by experience and is sensitive to the detection of unfamiliar signals.

Accumulating evidence suggests that deficits in perceptual inference account for symptoms of schizophrenia. One manifestation of perceptual inference is the central bias, i.e., the tendency to put emphasis on prior experiences over actual events in perceiving incoming sensory stimuli. Using an interval reproduction task, this study aimed to determine whether patients with schizophrenia show a stronger central bias than participants without schizophrenia. In the interval reproduction task, participants were shown a cross on a screen. The cross was replaced with a Gaussian patch for a predetermined time interval, and participants were required to reproduce the interval duration by pressing and releasing the space key. We manipulated the uncertainty of prior information using different interval distributions. We found no difference in the influence of prior information on interval reproduction between patients and controls. However, patients with SZ showed a stronger central bias than healthy participants in the intermediate interval range (approximately 450 ms to 900 ms). It is possible that the patients in SZ have non-uniform deficits associated with interval range or uncertainty of prior information in perceptual inference. Further, the severity of avolition and alogia was correlated with the strength of central bias in SZ. This study provides some insights into the mechanisms underlying the association between schizophrenic symptoms and perceptual inference.

Although results of many psychology studies have shown that sharing emotion achieves dyadic interaction, no report has explained a study of the transmission of authentic information from emotional expressions that can strengthen perceivers. For this study, we used computational modeling, which is a multinomial processing tree, for formal quantification of the process of sharing emotion that emphasizes the perception of authentic information for expressers’ feeling states from facial expressions. Results indicated that the ability to perceive authentic information of feeling states from a happy expression has a higher probability than the probability of judging authentic information from anger expressions. Next, happy facial expressions can activate both emotional elicitation and sharing emotion in perceivers, where emotional elicitation alone is working rather than sharing emotion for angry facial expressions. Third, parameters to detect anger experiences were found to be correlated positively with those of happiness. No robust correlation was found between the parameters extracted from this experiment task and questionnaire-measured emotional contagion, empathy, and social anxiety. Results of this study revealed the possibility that a new computational approach contributes to description of emotion sharing processes.

The exploration of personality factors to explain individual differences in religiosity has demonstrated a link between empathic concern and religious beliefs using the Empathic Concern subscale of the Interpersonal Reactivity Index (IRI-EC). Research in the cognitive science of religion emphasized the role of empathizing ability related to mentalizing in acquisition of religious belief and has demonstrated the relationship between the Empathy Quotient (EQ) and religious belief. The current study was designed to compare the strength of relationships between religious belief and two representative measures of empathy (the IRI-EC and the EQ). Study 1 aimed to statistically evaluate the strength of the relationship between the EQ/IRI-EC and religious belief with four Japanese samples (Ns = 207, 155, 208, 183). The mini meta-analysis results with random effect model indicated that the effect size (semi partial correlation, r sp) of the IRI-EC (r sp = .120, 95%CI [.0002,.237]) was larger than that of the EQ (r sp = .074, 95%CI [−.0001,.147]). Moreover, these results were confirmed by Study 2 (N = 1440). Thus, the present study provided reliable evidence of the link between empathy and religious belief in non-Western samples. We discuss how empathic concern and mentalizing-related empathy contribute to acquiring religious beliefs. Abbreviations: EQ: Empathy Quotient; IRI-EC: Interpersonal Reactivity Index-Empathic Concern; WEIRD: Western, educated, industrialized, rich, and democratic.

Abstract

According to a space-valence association, individuals tend to relate negatively- and positively-connoted stimuli with the left and right side of space, respectively. So far, only a few studies have explored whether this phenomenon can also emerge for social dimensions associated with facial stimuli. Here, we adopted a cross-cultural approach and conducted two experiments with the main aim to test whether a left–right space-valence association can also emerge for other- vs. own-race faces. Asian Japanese (Experiment 1) and White Italian (Experiment 2) participants engaged in a speeded binary classification task in which a central placed face had to be classified as either Asian or White. Manual responses were provided through a left- vs. right-side button. In both experiments, other-race faces elicited faster responses than own-race faces, in line with the well-documented other-race categorisation advantage. Moreover, evidence of an association between space and ethnic membership also arose and, interestingly, was similar in both groups. Indeed, Asian faces were responded to faster with the right-side key than with the left-side key, whereas response side had no effect for White faces. These results are discussed with regard to possible cross-cultural differences in group perception.

Scientists conducting affective research often use visual, emotional images, to examine the mechanisms of defensive responses to threatening and dangerous events and objects. Many studies use the rich emotional images from the International Affective Picture System (IAPS) to facilitate affective research. While IAPS images can be classified into emotional categories such as fear or disgust, the number of images per discrete emotional category is limited. We developed the Open Biological Negative Image Set (OBNIS) consisting of 200 colour and greyscale creature images categorized as disgusting, fearful or neither. Participants in Experiment 1 (
<italic>N</italic>
= 210) evaluated the images' valence and arousal and classified them as
<italic>disgusting</italic>
,
<italic>fearful</italic>
or
<italic>neither.</italic>
In Experiment 2, other participants (
<italic>N</italic>
= 423) rated the disgust and fear levels of the images. As a result, the OBNIS provides valence, arousal, disgust and fear ratings and ‘disgusting,’ 'fearful' and ‘neither’ emotional categories for each image. These images are available to download on the Internet (
<uri xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://osf.io/pfrx4/?view_only=911b1be722074ad4aab87791cb8a72f5">https://osf.io/pfrx4/?view_only=911b1be722074ad4aab87791cb8a72f5</uri>
).

Musicians tend to have better auditory and motor performance than non-musicians because of their extensive musical experience. In a previous study, we established that loudness discrimination acuity is enhanced when sound is produced by a precise force generation task. In this study, we compared the enhancement effect between experienced pianists and non-musicians. Without the force generation task, loudness discrimination acuity was better in pianists than non-musicians in the condition. However, the force generation task enhanced loudness discrimination acuity similarly in both pianists and non-musicians. The reaction time was also reduced with the force control task, but only in the non-musician group. The results suggest that the enhancement of loudness discrimination acuity with the precise force generation task is independent of musical experience and is, therefore, a fundamental function in auditory-motor interaction.

Objective. Brain decoding of motor imagery (MI) not only is crucial for the control of neuroprosthesis but also provides insights into the underlying neural mechanisms. Walking consists of stance and swing phases, which are associated with different biomechanical and neural control features. However, previous knowledge on decoding the MI of gait is limited to simple information (e.g. the classification of 'walking' and 'rest').Approach. Here, we investigated the feasibility of electroencephalogram (EEG) decoding of the two gait phases during the MI of walking and whether the combined use of MI and action observation (AO) would improve decoding accuracy.Main results. We demonstrated that the stance and swing phases could be decoded from EEGs during MI or AO alone. We also demonstrated the decoding accuracy during MI was improved by concurrent AO. The decoding models indicated that the improved decoding accuracy following the combined use of MI and AO was facilitated by the additional information resulting from the concurrent cortical activations related to sensorimotor, visual, and action understanding systems associated with MI and AO.Significance. This study is the first to show that decoding the stance versus swing phases during MI is feasible. The current findings provide fundamental knowledge for neuroprosthetic design and gait rehabilitation, and they expand our understanding of the neural activity underlying AO, MI, and AO + MI of walking.Novelty and significanceBrain decoding of detailed gait-related information during motor imagery (MI) is important for brain-computer interfaces (BCIs) for gait rehabilitation. This study is the first to show the feasibility of EEG decoding of the stance versus swing phases during MI. We also demonstrated that the combined use of MI and action observation (AO) improves decoding accuracy, which is facilitated by the concurrent and synergistic involvement of the cortical activations for MI and AO. These findings extend the current understanding of neural activity and the combined effects of AO and MI and provide a basis for effective techniques for walking rehabilitation.

<title>Abstract</title>
Human facial attractiveness is evaluated by using multiple cues. Among others, sexual dimorphism (i.e. masculinity for male faces/femininity for female faces) is an influential factor of perceived attractiveness. Since facial attractiveness is judged by incorporating sexually dimorphic traits as well as other cues, it is theoretically possible to dissociate sexual dimorphism from facial attractiveness. This study tested this by using a data-driven mathematical modelling approach. We first analysed the correlation between perceived masculinity/femininity and attractiveness ratings for 400 computer-generated male and female faces (Experiment 1) and found positive correlations between perceived femininity and attractiveness for both male and female faces. Using these results, we manipulated a set of faces along the attractiveness dimension while controlling for sexual dimorphism by orthogonalisation with data-driven mathematical models (Experiment 2). Our results revealed that perceived attractiveness and sexual dimorphism are dissociable, suggesting that there are as yet unidentified facial cues other than sexual dimorphism that contribute to facial attractiveness. Future studies can investigate the true preference of sexual dimorphism or the genuine effects of attractiveness by using well-controlled facial stimuli like those that this study generated. The findings will be of benefit to the further understanding of what makes a face attractive.

During joint action, two or more persons depend on each other to accomplish a goal. This mutual recursion, or circular dependency, is one of the characteristics of cooperation. To evaluate the neural substrates of cooperation, we conducted a hyperscanning functional MRI study in which 19 dyads performed a joint force-production task. The goal of the task was to match their average grip forces to the target value (20% of their maximum grip forces) through visual feedback over a 30-s period; the task required taking into account other-produced force to regulate the self-generated one in real time, which represented cooperation. Time-series data of the dyad's exerted grip forces were recorded, and the noise contribution ratio (NCR), a measure of influence from the partner, was computed using a multivariate autoregressive model to identify the degree to which each participant's grip force was explained by that of their partner's, i.e., the degree of cooperation. Compared with the single force-production task, the joint task enhanced the NCR and activated the mentalizing system, including the medial prefrontal cortex, precuneus, and bilateral posterior subdivision of the temporoparietal junction (TPJ). In addition, specific activation of the anterior subdivision of the right TPJ significantly and positively correlated with the NCR across participants during the joint task. The effective connectivity of the anterior to posterior TPJ was upregulated when participants coordinated their grip forces. Finally, the joint task enhanced cross-brain functional connectivity of the right anterior TPJ, indicating shared attention toward the temporal patterns of the motor output of the partner. Since the posterior TPJ is part of the mentalizing system for tracking the intention of perceived agents, our findings indicate that cooperation, i.e., the degree of adjustment of individual motor output depending on that of the partner, is mediated by the interconnected subdivisions of the right TPJ.

Facial attractiveness is judged through a combination of multiple cues including morphology (facial shape) and skin properties (facial reflectance). While several studies have examined the way in which people in Western cultures judge facial attractiveness, there have been fewer investigations into non-Western attitudes. This is because stimuli that quantitatively vary the attractiveness of non-Western faces are rare. In the present study, we built a model of the attractiveness of East-Asian faces, judged by East-Asian observers. Therefore, 400 computer-generated East-Asian faces were created and attractiveness rating scores were collected from Japanese observers. Data-driven mathematical calculations were used to identify quantitative links between facial attractiveness and shape and reflectance properties, with no prior hypothesis. Results indicate that faces with larger eyes, smaller noses and brighter skin are judged as more attractive, regardless of the sex of the faces, possibly reflecting a general preference for femininity. Shape is shown to be a strong determinant of attractiveness for both male and female faces, while reflectance properties are less important in judging male facial attractiveness. Our model provides a tool to effectively produce East-Asian face stimuli that quantitatively varies attractiveness and can be used to elucidate visual processes related to attractiveness judgements.

Muscular control during walking is believed to be simplified by the coactivation of muscles called muscle synergies. Although significant corticomuscular connectivity during walking has been reported, the level at which the cortical activity is involved in muscle activity (muscle synergy or individual muscle level) remains unclear. Here we examined cortical correlates of muscle activation during walking by brain decoding of activation of muscle synergies and individual muscles from electroencephalographic signals. We demonstrated that the activation of locomotor muscle synergies was decoded from slow cortical waves. In addition, the decoding accuracy for muscle synergies was greater than that for individual muscles and the decoding of individual muscle activation was based on muscle-synergy-related cortical information. These results indicate the cortical correlates of locomotor muscle synergy activation. These findings expand our understanding of the relationships between brain and locomotor muscle synergies and could accelerate the development of effective brain-machine interfaces for walking rehabilitation.

We present an open-source software platform that transforms emotional cues expressed by speech signals using audio effects like pitch shifting, inflection, vibrato, and filtering. The emotional transformations can be applied to any audio file, but can also run in real time, using live input from a microphone, with less than 20-ms latency. We anticipate that this tool will be useful for the study of emotions in psychology and neuroscience, because it enables a high level of control over the acoustical and emotional content of experimental stimuli in a variety of laboratory situations, including real-time social situations. We present here results of a series of validation experiments aiming to position the tool against several methodological requirements: that transformed emotions be recognized at above-chance levels, valid in several languages (French, English, Swedish, and Japanese) and with a naturalness comparable to natural speech.

Facial attractiveness can be judged on the basis of visual information acquired in a very short duration, but the absolute level of attractiveness changes depending on the duration of the observation. However, how information from individual facial parts contributes to the judgment of whole-face attractiveness is unknown. In the current study, we examined how contributions of facial parts to the judgment of whole-face attractiveness would change over time. In separate sessions, participants evaluated the attractiveness of whole faces, as well as of the eyes, nose, and mouth after observing them for 20, 100, and 1,000 ms. Correlation and multiple regression analyses indicated that the eyes made a consistently high contribution to whole-face attractiveness, even with an observation duration of 20 ms, whereas the contribution of other facial parts increased as the observation duration grew longer. When the eyes were averted, the attractiveness ratings for the whole face were decreased marginally. In addition, the contribution advantage of the eyes at the 20-ms observation duration was diminished. We interpret these results to indicate that (a) eye gaze signals social attractiveness at the early stage (perhaps in combination with emotional expression), (b) other facial parts start contributing to the judgment of whole-face attractiveness by forming aesthetic attractiveness, and (c) there is a dynamic interplay between social and aesthetic attractiveness.

Research has shown that people often exert control over their emotions. By modulating expressions, reappraising feelings, and redirecting attention, they can regulate their emotional experience. These findings have contributed to a blurring of the traditional boundaries between cognitive and emotional processes, and it has been suggested that emotional signals are produced in a goal-directed way and monitored for errors like other intentional actions. However, this interesting possibility has never been experimentally tested. To this end, we created a digital audio platform to covertly modify the emotional tone of participants' voices while they talked in the direction of happiness, sadness, or fear. The result showed that the audio transformations were being perceived as natural examples of the intended emotions, but the great majority of the participants, nevertheless, remained unaware that their own voices were being manipulated. This finding indicates that people are not continuously monitoring their own voice to make sure that it meets a predetermined emotional target. Instead, as a consequence of listening to their altered voices, the emotional state of the participants changed in congruence with the emotion portrayed, which was measured by both self-report and skin conductance level. This change is the first evidence, to our knowledge, of peripheral feedback effects on emotional experience in the auditory domain. As such, our result reinforces the wider framework of self-perception theory: that we often use the same inferential strategies to understand ourselves as those that we use to understand others.

People tend to assimilate toward each other. Importantly, assimilations occur both explicitly and implicitly at various levels, ranging from low-level sensory-motor coordination to high-level conceptual mimicry. Teaching is often confused with simply one means of enhancing learning. However, as we shall see in the other articles in this issue, teaching is a dynamic phenomenon where interpersonal interactions occur explicitly and implicitly at multiple levels. Bonding through coordinated interpersonal interactions occupies a substantial portion of teaching. In this article, I would like to introduce two interpersonal phenomena that exemplify implicit interactions and discuss their relations to the new realization of teaching.

Visual working memory is an online workspace for temporarily representing visual information from the environment. The two most prevalent empirical characteristics of working memory are that it is supported by sustained neural activity over a delay period and it has a severely limited capacity for representing multiple items simultaneously. Traditionally, such delay activity and capacity limits have been considered to be exclusive for maintaining information about objects that are no longer visible to the observers. Here, by contrast, we provide both neurophysiological and psychophysical evidence that the sustained neural activity and capacity limits for items that are continuously visible to the human observer are indistinguishable from those measured for items that are no longer visible. This holds true even when the observers know that the objects will not disappear from the visual field. These results demonstrate that our explicit representation of objects that are still "in view" is far more limited than previously assumed.

One may have experienced his or her footsteps unconsciously synchronize with the footsteps of a friend while walking together, or heard an audience's clapping hands naturally synchronize into a steady rhythm. However, the mechanisms of body movement synchrony and the role of this phenomenon in implicit interpersonal interactions remain unclear. We aimed to evaluate unconscious body movement synchrony changes as an index of implicit interpersonal interaction between the participants, and also to assess the underlying neural correlates and functional connectivity among and within the brain regions. We found that synchrony of both fingertip movement and neural activity between the two participants increased after cooperative interaction. These results suggest that the increase of interpersonal body movement synchrony via interpersonal interaction can be a measurable basis of implicit social interaction. The paradigm provides a tool for identifying the behavioral and the neural correlates of implicit social interaction.

A number of studies have shown that current-trial responses are biased toward the response of the preceding trial in perceptual decisionmaking tasks (the sequential effect Holland and Lockhead, 1968 Perception & Psychophysics 3 409-414). The sequential effect has been widely observed in evaluation of the physical properties of stimuli as well as more complex properties. However, it is unclear whether subjective decisions (eg attractiveness judgments) are also susceptible to the sequential effect. Here, we examined whether the sequential effect would occur in face-attractiveness judgments. Forty-eight pictures of male and female faces were presented successively. Participants rated the attractiveness of each face on a 7-point scale. The results showed that the attractiveness rating of a given face assimilated toward the rating of the preceding trial. In a separate experiment, we provided the average attractiveness rating by others for each trial as feedback. The feedback weakened the sequential effect. These findings suggest that attractiveness judgment is also biased toward the preceding judgment, and hence the sequential effect can be extended into the domain of subjective decisionmaking.

A brief visual cue that attracts attention repels the perceived location of a subsequent visual stimulus away from the focus of attention (attentional repulsion). In the first experiment reported here, we presented a visual cue after a visual target and found that the perceived location of the target stimulus shifted toward the location of the cue (attentional attraction). The subsequent experiments ruled out nonattentional hypotheses and indicated that the mislocalization effect is attributable to the attentional shift. The results of this study suggest that preceding and succeeding contexts differentially modulate the perceived location of a briefly presented stimulus. Our findings also underscore the importance of retrospective processes in visual attention.

To coordinate our actions with those of others, it is crucial to not only choose an appropriate category of action but also to execute it at an appropriate timing. It is widely documented that people tend to unconsciously mimic others' behavior. The present study show that people also tend to modify their movement timing according to others' movements even when the observed and the to-be-executed movements are unrelated. Observers viewed either point-light biological motion, scrambled biological motion, or solid object motion. The stimulus sequence was presented at three different (half, normal, and double) rates. After a 300-2400-ms blank period, the observers performed a simple choice reaction-time task that was unrelated to the presented stimulus sequence. The observation of the biological motion produced a negative correlation between reaction time and stimulus speed, whereas no such trend was observed with the scrambled or solid object motion. Furthermore, speed-dependent modulation occurred only when the task was imposed within approximately 1 s after the offset of the biological motion. These results suggest that behavioral tempo may be contagious; the speed of others' movements may automatically influence the timing of movement execution by the observer. (C) 2007 Elsevier B.V. All rights reserved.

The relative visual position of a briefly flashed stimulus is systematically modified in the presence of motion signals. We investigated the two-dimensional distortion of the positional representation of a flash relative to a moving stimulus. Analysis of the spatial pattern of mislocalization revealed that the perceived position of a flash was not uniformly displaced, but instead shifted toward a single point of convergence that followed the moving object from behind at a fixed distance. Although the absolute magnitude of mislocalization increased with motion speed, the convergence point remained unaffected. The motion modified the perceived position of a flash, but had little influence on the perceived shape of a spatially extended flash stimulus. These results demonstrate that motion anisotropically distorts positional representation after the shapes of objects are represented. Furthermore, the results imply that the flash-lag effect may be considered a special case of two-dimensional anisotropic distortion.

The primate caudate nucleus plays a crucial role in transforming cognitive/motivational information into eye movement signals. A subset of caudate projection neurons fire before a visual target's onset. This anticipatory activity is sensitive to position-reward contingencies and correlates with saccade latency, which is shorter toward a rewarded position. We recorded single-unit activity of caudate projection neurons to examine the dynamics of change in anticipatory activity immediately after switches of the position-reward contingency. Two monkeys performed a visually guided saccade task where only one position was associated with reward. The position-reward mapping remained constant within a block, but was reversed frequently between blocks without any indication to the monkey. Therefore the switch could be detected only by unexpected reward delivery or unexpected lack of reward. After the switch, both saccade latency and anticipatory activity showed reliable changes already in the second trial, whether or not the first trial was rewarded. However, anticipatory activity in the second trial was generally higher if the first trial was rewarded, and the measured saccade latencies could be better explained by the difference in anticipatory activity between the two caudate nuclei. We suggest that anticipatory activity of caudate neurons reflects the reversal set of reward-position contingency.

Accurately perceiving the activities of other people is a crucially important social skill of obvious survival value. Human vision is equipped with highly sensitive mechanisms for recognizing activities performed by others [Johansson, G. (1973). Visual perception of biological motion and a model for its analysis. Perception and Psychophysics, 14, 201; Johansson, G. (1976). Spatio-temporal differentiation and integration in visual motion perception: An experimental and theoretical analysis of calculus-like functions in visual data processing. Psychological Research, 38, 379]. One putative functional role of biological motion perception is to register the presence of biological events anywhere within the visual field, not just within central vision. To assess the salience of biological motion throughout the visual field, we compared the detectability performances of biological motion animations imaged in central vision and in peripheral vision. To compensate for the poorer spatial resolution within the periphery, we spatially magnified the motion tokens defining biological motion. Normal and scrambled biological motion sequences were embedded in motion noise and presented in two successively viewed intervals on each trial (2AFC). Subjects indicated which of the two intervals contained normal biological motion. A staircase procedure varied the number of noise dots to produce a criterion level of discrimination performance. For both foveal and peripheral viewing, performance increased but saturated with stimulus size. Foveal and peripheral performance could not be equated by any magnitude of size scaling. Moreover, the inversion effect-superiority of upright over inverted biological motion [Sumi, S. (1984). Upside-down presentation of the Johansson moving light-spot pattern. Perception, 13, 283]-was found only when animations were viewed within the central visual field. Evidently the neural resource responsible for biological motion perception are embodied within neural mechanisms focused on central vision. (c) 2005 Elsevier Ltd. All rights reserved.

Binocular rivalry elevates contrast increment thresholds for the detection of a transient stimulus presented to the suppressed eye, while thresholds measured during dominance are identical to those during, monocular viewing (e.g. [Wales, R., & Fox, R. (1970). Increment detection thresholds during binocular rivalry suppression. Perception and Psychophysics, 8, 90-94]). It is well established that contrast increment thresholds depend on reference (pedestal) contrast. With high contrasts, increment thresholds increase with pedestal contrast, reflecting a gain control with sigmoidal non-linearity. We examined how this gain control mechanism operates during binocular rivalry (i.e., with and without perception of a pedestal mask). Subjects viewed a horizontal sine-wave grating (steady pedestal) and a radial checkerboard dichoptically. When the grating achieved a pre-specified phenomenal state (dominance or suppressed), subjects initiated the transient presentation (500-ms Gaussian pulse) of a contrast increment of the same spatial frequency. The pulse appeared in either the upper or lower half of the pedestal. Subjects indicated which half of the pedestal contained the pulse. Contrast increment thresholds were measured using a staircase method with various pedestal contrasts, which yielded threshold versus contrast (TvC) functions during dominance and suppression. The measured thresholds were reliably higher during suppression, but the rising slopes of TvC functions did not differ significantly between dominance and suppression (i.e., constant upward shift of TvC function). A control experiment demonstrated that the TvC function during dominance was identical to that during non-rivalry, monocular viewing. Evidently, the contrast gain control for transient luminance increment does not require the perception of pedestal contrast. (C) 2004 Elsevier Ltd. All rights reserved.

The prospect of immediate reward elicits goal-oriented behavior. However, animals often have to perform actions that do not immediately lead to reward in the pursuit of a long-term goal. Here we identify neural activity in monkey caudate nucleus that specifically correlates with rewarded and unrewarded eye movements. The monkey performed a visually guided saccade task in which only one position was associated with positive reinforcement. To advance in the experimental session, however, the monkey had no choice but to complete a saccade to an unrewarded position as well as to a rewarded position. Some caudate saccadic neurons showed enhanced activity around the time of the saccade in rewarded trials ( rewarded-saccade neurons). Another subset of neurons discharged selectively around the execution of the saccade in unrewarded trials ( unrewarded-saccade neurons). In both rewarded and unrewarded trials, stronger activity of these neurons was associated with reduced saccade latency. These results suggest that both rewarded and unrewarded saccades are facilitated by caudate saccadic activity. The neuronal activity of unrewarded-saccade neurons might reflect the required execution of unrewarded eye movements on the way to future reward.

Primates are equipped with neural circuits in the prefrontal cortex(1-6), the parietal cortex(7) and the basal ganglia(6,8-11) that predict the availability of reward during the performance of behavioural tasks. It is not known, however, how reward value is incorporated in the control of action. Here we identify neurons in the monkey caudate nucleus that create a spatially selective response bias depending on the expected gain. In behavioural tasks, the monkey had to make a visually guided eye movement in every trial, but was rewarded for a correct response in only half of the trials. Reward availability was predictable on the basis of the spatial position of the visual target. We found that caudate neurons change their discharge rate systematically, even before the appearance of the visual target, and usually fire more when the contralateral position is associated with reward. Strong anticipatory activity of neurons with a contralateral preference is associated with decreased latency for eye movements in the contralateral direction. We conclude that this neuronal mechanism creates an advance bias that favours a spatial response when it is associated with a high reward value.

Two identical visual targets moving across each other can be perceived either to bounce off or to stream through each other. A brief sound at the moment the targets coincide biases perception toward bouncing. We found that this bounce-inducing effect was attenuated when other identical sounds (auditory flankers) were presented 300 ms before and after the simultaneous sound. The attenuation occurred only when the simultaneous sound and auditory flankers had similar acoustic characteristics and the simultaneous sound was not salient. These results suggest that there is an aspect of auditory-grouping (saliency-assigning) processes that is context-sensitive and can be utilized by the visual system for solving ambiguity. Furthermore, control experiments revealed that such auditory context did not affect the perceptual qualities of the simultaneous sound. Because the attenuation effect is not manifest in the perception of acoustic characteristics of individual sound elements, we conclude that it is a genuine cross-modal effect.

In a two-dimensional display, identical visual targets moving toward and across each other with equal, constant speed can be perceived either to reverse their motion directions at the coincidence point (bouncing percept) or to stream through one another (streaming percept). Although there is a strong tendency to perceive the streaming percept, various factors have been reported to induce the bouncing percept, such as a sound or a visual flash at the moment of the visual target coincidence. By changing duration of the postcoincidence trajectory (PCT), we investigated how long it would take for such bounce-inducing factors to be maximally effective after the visual coincidence. With bounce-inducing factors, the percentage of the bouncing percept did not reach its maximal level immediately after the coincidence but increased as a function of PCT duration up to 150-200 msec. The results clearly reject the possibility of the cognitive-bias hypothesis about the bounce-inducing effect and suggest rather that the bounce-inducing factors have to interact with the PCT for some period after the coincidence to be maximally effective.

Identical visual targets moving across each other with equal and constant speed can be perceived either to bounce off or to stream through each other. This bistable motion perception has been studied mostly in the context of motion integration. Since the perception of most ambiguous motion is affected by attention, there is the possibility of attentional modulation occurring in this case as well. We investigated whether distraction of attention from the moving targets would alter the relative frequency of each percept. During the observation of the streaming/bouncing motion event in the peripheral visual field, visual attention was disrupted by an abrupt presentation of a visual distracter at various timings and locations (experiment 1; exogenous distraction of attention) or by the demand of an additional discrimination task (experiments 2 and 3; endogenous distraction of attention). Both types of distractions of attention increased the frequency of the bouncing percept and decreased that of the streaming percept. These results suggest that attention may facilitate the perception of object motion as continuing in the same direction as in the past.

Even though humans are adept at distinguishing various faces, inversion dramatically spoils the ability. This face inversion effect is remarkably robust across observers; however, whether inversion impairs the perception of facial parts (particularly the eye) is inconsistent across studies. Some studies have shown that featural processing remains preserved or even enhanced when faces are inverted, while others have shown that inversion impairs featural processing. These mixed findings may result from confounding factors such as a small number of participants, an imbalanced participant sex ratio, and the varying nature of the tasks in previous reports. To address these issues, we assessed the effect sizes of face orientation, sex, and their interaction in low-level psychophysical discrimination of briefly presented gaze stimuli in a well-powered cohort with a balanced sex ratio (N = 190). The results revealed a medium-to-large-sized effect of inversion (f = 0.35) and a small-to-medium-sized effect of sex (f = 0.17) on gaze direction discrimination but no meaningful interaction (f = 0.05). Thus, our results demonstrated an almost equivalent gaze inversion effect between females and males (sex invariance) and a female superiority in overall gaze direction sensitivity (sex difference). We suggest that inversion impairs sensitivity to gaze direction, but whether it leads to a change in explicit behavioral performance may depend on specific task settings rather than the participant's sex.

When a novel stimulus (oddball) appears after repeated presentation of an identical stimulus, the oddball is perceived to last longer than the repeated stimuli, a phenomenon known as the oddball effect. We investigated whether the perceptual or physical differences between the repeated and oddball stimuli are more important for the oddball effect. To manipulate the perceptual difference while keeping their physical visual features constant, we used the Thatcher illusion, in which an inversion of a face hinders recognition of distortion in its facial features. We found that the Thatcherized face presented after repeated presentation of an intact face induced a stronger oddball effect when the faces were upright than when they were inverted (Experiment 1). However, the difference in the oddball effect between face orientations was not observed when the intact face was presented as the oddball after repeated presentation of a Thatcherized face (Experiment 2). These results were replicated when participants performed both the intact-repeated and Thatcherized-repeated conditions in a single experiment (Experiment 3). Two control experiments confirmed that the repeated presentation of the preceding stimuli is necessary for the difference in duration distortion to occur (Experiments 4 and 5). The results suggest the considerable role of perceptual processing in the oddball effect. We discuss the discrepancy in the results between the intact-repeated and Thatcherized-repeated conditions in terms of predictive coding.

A novel motion stimulus is perceived to last longer than the subsequent motion stimulus moving in the opposite direction. A previous study suggested that the discrepancy in the processing latency for different onset types, as measured by reaction time, may play a role in this duration expansion. The present study examined whether the speed of motion stimuli influences this duration expansion. Experiment 1 demonstrated that the duration expansion ceased to occur when the stimulus speed increased. Experiment 2 showed that the increase in the speed reduced the reaction time for various onset types. However, the size of the changes in the reaction time did not match the reduction in the magnitude of the duration expansion observed in Experiment 1. These results suggest that the increase in speed eliminates the duration expansion of the novel motion stimulus, but the difference in the processing latency alone may not be the sole mechanism.

People consistently associate colors with tastes (e.g., pink-sweet, yellow-sour). However, little has been known on the strength of those color-taste correspondences. The current study examined the congruency effect of color-taste correspondence using two Stroop word categorization tasks. The visual stimuli consisted of food names associated with sweet and sour tastes, presented in different shades of pink and yellow font colors. Participants were instructed to categorize the taste (sweet or sour) of the words in the Stroop word-taste categorization task and to discriminate the font color (pink or yellow) of the words in the Stroop word-color discrimination task. Results showed that participants responded faster in congruent conditions (sweet-pink and sour-yellow) than incongruent conditions (sweet-yellow and sour-pink) in both tasks. Specifically, yellow font colors facilitated the categorization of sour taste words compared to pink font colors, whereas sweet taste words facilitated the discrimination of pink font colors compared to sour taste words. These results provide further evidence for the congruency effect of color-taste correspondence in facilitating the processing of taste-related words and colors. Furthermore, the congruency effect was shown to operate bidirectionally, influencing both the conceptual meaning of tastes and perceptual color perception. This study highlights the significant interference effect of color-taste correspondence on cognitive processing as assessed by the Stroop task.

Color is associated with gender information (e.g., red-female). However, little has been known on the effect of color on sex recognition of human bodies. This study aimed to investigate whether the color red could influence the categorization of human bodies by sex, and the effect of contextual information. Visual stimuli were created using body silhouettes varying along the waist-to-hip ratio from female to male shapes. These stimuli were presented in conjunction with red, green, and gray colors, which were used either as body color (Experiment 1) or background color (Experiment 2). Participants were instructed to categorize the sex of the body stimuli as either male or female by pressing labeled keys. The results showed that when red was used as a body color, it induced a bias toward feminine body perception, while when used as a background color, it induced a bias toward masculine body perception. Thus, the color red influenced the sex categorization of human bodies, which being modulated by contextual information. These findings provided novel insights into the effect of contextual color cues in sex recognition of human bodies.

Abstract

Color carries gender information (e.g., red-female). This study explored whether background color could influence the gender categorization of human faces. Visual stimuli were generated from faces whose sexually dimorphic content was morphed monotonically from female to male perception. The face stimulus was presented upright (Experiment 1) and inverted (Experiment 2) with three background colors (i.e., red, green, and gray). Participants were instructed to categorize the gender of the face stimulus as male or female by pressing one of two labelled keys. Results showed that a red background could bias the gender of an ambiguous upright face toward a female compared with green and gray background colors (Experiment 1). However, this red effect was diminished when the face stimulus was inverted (Experiment 2). These results suggest that red background color interacting with facial configuration features biases gender perception toward a female face, possibly through top-down processing of learned associations between the color red and femininity.

Abstract

Objective. Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder, and identifying early autism biomarkers plays a vital role in improving detection and subsequent life outcomes. This study aims to reveal hidden biomarkers in the patterns of functional brain connectivity as recorded by the neuro-magnetic brain responses in children with ASD. Approach. We recorded resting-state magnetoencephalogram signals from thirty children with ASD (4–7 years) and thirty age and gender-matched typically developing (TD) children. We used a complex coherency-based functional connectivity analysis to understand the interactions between different brain regions of the neural system. The work characterizes the large-scale neural activity at different brain oscillations using functional connectivity analysis and assesses the classification performance of coherence-based (COH) measures for autism detection in young children. A comparative study has also been carried out on COH-based connectivity networks both region-wise and sensor-wise to understand frequency-band-specific connectivity patterns and their connections with autism symptomatology. We used artificial neural network (ANN) and support vector machine (SVM) classifiers in the machine learning framework with a five-fold CV technique. Main results. To classify ASD from TD children, the COH connectivity feature yields the highest classification accuracy of 91.66% in the high gamma (50–100 Hz) frequency band. In region-wise connectivity analysis, the second highest performance is in the delta band (1–4 Hz) after the gamma band. Combining the delta and gamma band features, we achieved a classification accuracy of 95.03% and 93.33% in the ANN and SVM classifiers, respectively. Using classification performance metrics and further statistical analysis, we show that ASD children demonstrate significant hyperconnectivity. Significance. Our findings support the weak central coherency theory in autism detection. Further, despite its lower complexity, we show that region-wise COH analysis outperforms the sensor-wise connectivity analysis. Altogether, these results demonstrate the functional brain connectivity patterns as an appropriate biomarker of autism in young children.

Each basic taste can be perceived differently due to stored knowledge and differences in receptor properties. Depending on how these tastes are perceived, eating behavior may change. In this study, we examined the relationships between subjective feelings of taste perception, taste preferences, and autistic traits with the behavior of adding flavor to food using an example of sprinkling salt on watermelon. From an online questionnaire survey among a general Japanese population, we found that salty and sour tastes could be subjectively perceived more quickly than sweet and umami tastes, in line with our expectations. Moreover, the hedonic responses to watermelon with salt were negatively correlated with a preference for bitter taste, i.e., those participants who dislike bitter taste sensations tended to enjoy watermelon with salt more. There was no correlation between the hedonic response to watermelon with salt and the subjective feeling of taste perceptions and autistic traits and no correlation between autistic traits, and the subjective feeling of taste perceptions and taste preferences. These results suggest that adding different tastes could be influenced by taste preferences; thus, the addition of a different taste was thought to be related to an unconscious motivation to reduce bitterness.

Abstract

In this study, we aimed to find biomarkers of autism in young children. We recorded magnetoencephalography (MEG) in thirty children (4–7 years) with autism and thirty age, gender-matched controls while they were watching cartoons. We focused on characterizing neural oscillations by amplitude (power spectral density, PSD) and phase (preferred phase angle, PPA). Machine learning based classifier showed a higher classification accuracy (88%) for PPA features than PSD features (82%). Further, by a novel fusion method combining PSD and PPA features, we achieved an average classification accuracy of 94% and 98% for feature-level and score-level fusion, respectively. These findings reveal discriminatory patterns of neural oscillations of autism in young children and provide novel insight into autism pathophysiology.

Actions shape what we see and memorize. A previous study suggested the interaction between motor and memory systems by showing that memory encoding for task-irrelevant items was enhanced when presented with motor-response cues. However, in the studies on the attentional boost effect, it has been revealed that detection of the target stimulus can lead to memory enhancement without requiring overt action. Thus, the direct link between the action and memory remains unclear. To exclude the effect of the target detection process as a potential confounder, this study assessed the benefit of action for memory by separating items from the response cue in time. In our pre-registered online experiment (N = 142), participants responded to visual Go cues by pressing a key (i.e., motor task) or counting (i.e., motor-neutral cognitive task) while ignoring No-go cues. In each trial, two task-irrelevant images were sequentially presented after the cue disappearance. After encoding the Go/No-go tasks, participants performed a surprise recognition memory test for those images. Importantly, we quantified the impact of overt execution of the action by comparing memories with and without motor response and the impact of covert motor processes (e.g., preparation and planning of action) by comparing memory between the motor and cognitive tasks. The results showed no memory differences between Go and No-go trials in the motor task. This means that the execution itself was not critical for memory enhancement. However, the memory performance in the motor No-go trials was higher than that in the cognitive No-go trials, only for the items presented away from the cues in time. Therefore, engaging the motor task itself could increase incidental memory for the task-irrelevant items compared to a passive viewing situation. We added empirical evidence on the online interaction between action and memory encoding. These memory advantages could be especially brought in action preparation and planning. We believe this fact may expand our present understanding of everyday memory, such as active learning.

Individuals with autism spectrum disorder exhibit atypical taste perception and eating behaviours. However, little is known about the effect of autistic traits on eating behaviours in the general population. This study explored the relationships between autistic traits, taste preferences, taste perceptions, and eating behaviours among Japanese population using an online questionnaire survey. The results showed significant effect of autistic traits on eating behaviours, that people with higher autistic traits tended to have higher selective eating behaviours, such as increased sensitivity to food texture and mixed flavours. Moreover, selective eating behaviours were correlated with the preference for sour taste and aftertaste sensitivity. Those results suggest that eating behaviours can be influenced by the relationship between autistic traits, taste perceptions, and taste preferences. We discuss these results in the context of previous findings, and future investigations into the possibility of solving selective eating problems in individuals with autism.

Crossmodal correspondences between visual features (e.g., color/shape) and tastes have been extensively documented in recent years. Visual colors and shapes have been shown to consensually match to specific tastes. Meanwhile, individuals with autism spectrum disorder are reported to have atypical sensory processing and deficits in multisensory integration. However, the influence of autistic traits on the formation of such correspondences is relatively unknown. Here, we examined whether autistic traits could influence visual–taste associations using an online questionnaire survey among Japanese participants. The results showed that the participants exhibited strong color–taste, shape–taste, and shape–color associations, and the proportions of choosing the consensual color–taste/shape–color associations were significantly associated with autistic traits. The participants with higher autistic quotient scores chose fewer of the consensual color–taste/shape–color associations while there was no difference in choosing shape–taste associations. We interpreted the results as statistical learning with a reduced prior knowledge effect in participants with higher autistic quotient scores.

<title>Abstract</title>Sexual motivation strongly influences mate choice and dating behavior and can be triggered by merely viewing sexually arousing visual images, such as erotic pictures and movies. Previous studies suggested that men, more than women, tend to search for sexual cues that signal promiscuity in short-term mates. However, it remains to be tested whether sex differences in the motivation to view sexual cues can be observed by using robust and well-controlled behavioral measures. To this end, we employed a pay-per-view key-pressing task. Japanese self-identified heterosexual male and female participants viewed images of men, women, or couples with two levels of sexual arousal (sexual vs. less sexual). Participants could alter the viewing time of a presented image according to their willingness to keep viewing it. Male participants were the most eager to view sexually arousing images of the opposite sex, whereas female participants were more strongly motivated to view less sexual images of couples. Such sex differences may reflect differentiated reproductive strategies between men and women in terms of men’s motivation toward promiscuity and women’s motivation toward long-term relationships.

Motor executions alter sensory processes. Studies have shown that loudness perception changes when a sound is generated by active movement. However, it is still unknown where and how the motor-related changes in loudness perception depend on the task demand of motor execution. We examined whether different levels of precision demands in motor control affects loudness perception. We carried out a loudness discrimination test, in which the sound stimulus was produced in conjunction with the force generation task. We tested three target force amplitude levels. The force target was presented on a monitor as a fixed visual target. The generated force was also presented on the same monitor as a movement of the visual cursor. Participants adjusted their force amplitude in a predetermined range without overshooting using these visual targets and moving cursor. In the control condition, the sound and visual stimuli were generated externally (without a force generation task). We found that the discrimination performance was significantly improved when the sound was produced by the force generation task compared to the control condition, in which the sound was produced externally, although we did not find that this improvement in discrimination performance changed depending on the different target force amplitude levels. The results suggest that the demand for precise control to produce a fixed amount of force may be key to obtaining the facilitatory effect of motor execution in auditory processes.

This study introduces a novel approach to investigate human facial attractiveness’s intrinsic psychophysical function using a sequential experimental design with a combination of Bayesian optimization (BO) and StyleGAN2. To estimate a facial attractiveness function from pairwise comparison data, we used a BO that incorporates Gaussian process preference learning (GPPL). Fifty female Japanese university students provided facial photographs. We embedded each female facial image into a latent representation (18 × 512 dimensions) in the StyleGAN2 network trained on the Flickr-Faces-HQ (FFHQ) dataset. Using PCA, the latent representations’ dimension is reduced to an 8-dimensional subspace, which we refer to here as the Japanese female face space. Nine participants participated in the pairwise comparison task. They had to choose the more attractive facial images synthesized using StyleGAN2 in the face subspace and provided their evaluations in 100 trials. The stimuli for the first 80 trials were created from randomly generated parameters in the face subspace, while the remaining 20 trials were created from the parameters calculated using the acquisition function. We estimated the facial parameters corresponding to the most, the least, 25, 50, 75 percentile rank of attractiveness and reconstructed the faces based on the results. The results show that a combination of StyleGAN2 and GPPL methodologies is an effective way to elucidate human kansei evaluations of complex stimuli such as human faces.

<title>Abstract</title>
The theory of event coding, an influential framework for action planning, suggests that humans first integrate stimulus, response, and action effect into representation (an event file) via their contingencies, and then, the activation of expected action effects drives the associated response. While previous studies have typically examined such functions of action effects after, rather than before or during, the acquirement of the representation, Eitam et al. (Exp Brain Res 229:475–484, 2013a) demonstrated that the presence of immediate feedback to action (i.e., action effects) can instantly elicit faster responses than delayed feedback. However, the underlying mechanism of this faciliatory effect remains unclear. Specifically, while the response–effect relationship has been highlighted, the role of stimuli has not been investigated. To address this issue, the present study conducted four experiments. We first reproduced the faciliatory effects of immediate action effects with between- and within-participants design (Experiments 1 and 2, respectively). Then, we assessed whether immediate action effects facilitate response speed, when stimuli (Experiment 3) and a combination of stimuli and responses (Experiment 4) determined the delay of action effects. The identical response was executed faster when driven by stimuli associated with immediate effects than by those associated with lagged effects. This result indicates that immediate action effects do not reinforce the execution of specific motor actions itself, but facilitate actions depending on the stimulus–response relationship. We discuss the potential mechanism of the facilitation effect.

Abstract

Whether people have insight into their face recognition ability has been intensely debated in recent studies using self-report measures. Although some studies showed people’s good insight, other studies found the opposite. The discrepancy might be caused by the difference in the questionnaire used and/or the bias induced using an extreme group such as suspected prosopagnosics. To resolve this issue, we examined the relationship between the two representative self-report face recognition questionnaires (Survey, N = 855) and then the extent to which the questionnaires differ in their relationship with face recognition performance (Experiment, N = 180) in normal populations, which do not include predetermined extreme groups. We found a very strong correlation (r = 0.82), a dominant principal component (explains &gt; 90% of the variance), and comparable reliability between the questionnaires. Although these results suggest a strong common factor underlying them, the residual variance is not negligible (33%). Indeed, the follow-up experiment showed that both questionnaires have significant but moderate correlations with actual face recognition performance, and that the correlation was stronger for the Kennerknecht’s questionnaire (r =  − 0.38) than for the PI20 (r =  − 0.23). These findings not only suggest people’s modest insight into their face recognition ability, but also urge researchers and clinicians to carefully assess whether a questionnaire is suitable for estimating an individual’s face recognition ability.

Abstract. In this experiment, we replicated the effect of muscle engagement on perception such that the recognition of another’s facial expressions was biased by the observer’s facial muscular activity (Blaesi &amp; Wilson, 2010). We extended this replication to show that such a modulatory effect is also observed for the recognition of dynamic bodily expressions. Via a multilab and within-subjects approach, we investigated the emotion recognition of point-light biological walkers, along with that of morphed face stimuli, while subjects were or were not holding a pen in their teeth. Under the “pen-in-the-teeth” condition, participants tended to lower their threshold of perception of happy expressions in facial stimuli compared to the “no-pen” condition, thus replicating the experiment by Blaesi and Wilson (2010). A similar effect was found for the biological motion stimuli such that participants lowered their threshold to perceive happy walkers in the pen-in-the-teeth condition compared to the no-pen condition. This pattern of results was also found in a second experiment in which the no-pen condition was replaced by a situation in which participants held a pen in their lips (“pen-in-lips” condition). These results suggested that facial muscular activity alters the recognition of not only facial expressions but also bodily expressions.

Empathy with another's pain is an important social glue for maintaining interpersonal relationships. In most previous studies investigating the sharing of pain, a signal conveying a painful experience is presented by a target ("sender") as a stimulus to a participant ("receiver"), and the emotional/physiological responses of the participant are measured. However, this unilateral "sender-receiver" paradigm does not adequately address the possible bidirectional experience of shared pain accruing from interaction. Our aim was therefore to investigate the bidirectional effects of sharing pain in social settings. Thirty-six unfamiliar pairs were simultaneously and repeatedly exposed to the same pain-provoking (thermal) stimuli, either in a face-to-face or a "shielded" condition where a partition prevented the partner's responses from being fully observed. We recorded the blood volume pulse of each participant to measure the acute sympathetic response while a pair of participants experienced the stimuli simultaneously. The results revealed that participants with weaker reactions elevated their physiological reactivity to the stimulus in accordance with their partner's reactions in the face-to-face condition. The pair-level physiological similarity was also higher compared to the shielded condition. Such a low-to-high physiological convergence may underlie the collective elevation of pain expressions, which is often observed in interactive settings.

To respond to movements of others and understand the intention of others' actions, it is important to accurately extract motion information from body movements. Here, using original and spatially scrambled point-light biological motions in upright and inverted orientations, we investigated the effect of global and local biological motion information on speed perception and sensitivity. The speed discrimination task revealed that speed sensitivity was higher for the original than for scrambled stimuli (Experiment 1) and higher for upright than for inverted stimuli (Experiment 2). Perceived motion speed was slower for the original than for scrambled stimuli (Experiment 2), but regardless of the orientation of the display (Experiment 1). A subsequent experiment comparing different scrambled stimuli of the same actions showed that the higher speed discrimination sensitivity to upright stimuli was preserved even in the scrambled biological motions (Experiment 3). Taken together, our findings suggest that perception of the speed of biological movements emanates from both global and local biological motion signals.

© 2017 Elsevier Ltd Food appearance influences the food's perceived value. It is paradoxical that animal-shaped foods (e.g., animal crackers) are popular and widely accepted among consumers, given that foods with an animal likeness usually elicit emotional disgust and avoidance behaviors. We experimentally tested the psychological influences of animal-themed food decorations. Participants evaluated their willingness to eat chocolate, kamaboko (a Japanese processed seafood product), and sashimi on which pictures of animals had been painted. We found that the perceived value of food did not improve by adding animal-themed decorations. In fact, the decoration drastically reduced the value of the foods actually made from animals (i.e., kamaboko and sashimi). The model analyses further confirmed that the psychological influences of animal-themed food decorations partly depended on whether the food was of animal origin or not. Furthermore, animal pictures with stronger animacy (i.e., realism) enhanced the negative influences of these decorations on the willingness to eat kamaboko and sashimi. These results together suggest that animal-themed food decorations do not enhance the value of food per se, perhaps because they emphasize the resemblance of foods to animals and thereby increase emotional disgust.

© The Author(s) 2017. A person’s direction of gaze (and visual attention) can be inferred from the direction of the parallel shift of the eyes. However, the direction of gaze is ambiguous when there is a misalignment between the eyes. The use of schematic drawings of faces in a previous study demonstrated that gaze-cueing was equally effective, even when one eye looked straight and the other eye was averted. In the current study, we used more realistic computer-generated face models to re-examine if the diverging direction of the eyes affected gaze-cueing. The condition where one eye was averted nasally while the other looked straight produced a significantly smaller gaze-cueing effect in comparison with when both eyes were averted in parallel or one eye was averted temporally. The difference in the gaze-cueing effect disappeared when the position of one eye was occluded with a rectangular surface or an eye-patch. These results highlight the possibility that the gaze-cueing effect might be weakened when a direct gaze exists between the cueing eye (i.e., nasally oriented eye) and the target and the effect magnitude might depend on which type of face stimulus are used as a cue.

A large proportion of very humanlike androids are assigned aesthetics typically associated with femininity. Ethical and discriminatory issues have yet to be given in-depth attention in procedural literature. This position paper suggests that implicitly viewing humanlike robots as agents that could, in future, substitute undesirable and/or exploitable humans may affect not just the robots' design, but also the human demographics considered replaceable. Such tendencies must be carefully considered by researchers, businesses, and policy makers. Interdisciplinary analysis may inform and expand social and cultural negotiations in the design of these androids.

Autism spectrum disorder (ASD) is a developmental disorder that involves developmental delays. It has been hypothesized that aberrant neural connectivity in ASD may cause atypical brain network development. Brain graphs not only describe the differences in brain networks between clinical and control groups, but also provide information about network development within each group. In the present study, graph indices of brain networks were estimated in children with ASD and in typically developing (TD) children using magnetoencephalography performed while the children viewed a cartoon video. We examined brain graphs from a developmental point of view, and compared the networks between children with ASD and TD children. Network development patterns (NDPs) were assessed by examining the association between the graph indices and the raw scores on the achievement scale or the age of the children. The ASD and TD groups exhibited different NDPs at both network and nodal levels. In the left frontal areas, the nodal degree and efficiency of the ASD group were negatively correlated with the achievement scores. Reduced network connections were observed in the temporal and posterior areas of TD children. These results suggested that the atypical network developmental trajectory in children with ASD is associated with the development score rather than age.

Through practice, people are able to integrate a secondary sequence (e.g., a stimulus-based sequence) into a primary sequence (e.g., a response-based sequence), but it is still controversial whether the integrated sequences lead to better learning than only the primary sequence. In the present study, we aimed to investigate the effects of a sequence that integrated space and color sequences on early and late learning phases (corresponding to effector-independent and effector-dependent learning, respectively) and how the effects differed in the integrated and primary sequences in each learning phase. In the task, the participants were required to learn a sequence of button presses using trial-and-error and to perform the sequence successfully for 20 trials (m x n task). First, in the baseline task, all participants learned a non-colored sequence, in which the response button always turned red. Then, in the learning task, the participants were assigned to two groups: a colored sequence group (i.e., space and color) or a non-colored sequence group (i.e., space). In the colored sequence, the response button turned a pre-determined color and the participants were instructed to attend to the sequences of both location and color as much as they could. The results showed that the participants who performed the colored sequence acquired the correct button presses of the sequence earlier, but showed a slower mean performance time than those who performed the non-colored sequence. Moreover, the slower performance time in the colored sequence group remained in a subsequent transfer task in which the spatial configurations of the buttons were vertically mirrored from the learning task. These results indicated that if participants explicitly attended to both the spatial response sequence and color stimulus sequence at the same time, they could develop their spatial representations of the sequence earlier (i.e., early development of the effector-independent learning), but might not be able to enhance their motor representations of the sequence (i.e., late development of the effector-dependent learning). Thus, the undeveloped effector-dependent representations in the colored sequence group directly led to a long performance time in the transfer sequence.

In the present study, we examined the effects of explicit knowledge, obtained through instruction or spontaneous detection, on the transfer of visuomotor sequence learning. In the learning session, participants learned a visuomotor sequence, via trial and error. In the transfer session, the order of the sequence was reversed from that of the learning session. Before the commencement of the transfer session, some participants received explicit instruction regarding the reversal rule (i.e., Instruction group), while the others did not receive any information and were sorted into either an Aware or Unaware group, as assessed by interview conducted after the transfer session. Participants in the Instruction and Aware groups performed with fewer errors than the Unaware group in the transfer session. The participants in the Instruction group showed slower speed than the Aware and Unaware groups in the transfer session, and the sluggishness likely persisted even in late learning. These results suggest that explicit knowledge reduces errors in visuomotor skill transfer, but may interfere with performance speed, particularly when explicit knowledge is provided, as opposed to being spontaneously discovered.

Visual working memory (VWM) enables active maintenance of goal-relevant visual information in a readily accessible state. The storage capacity of VWM is severely limited, often as few as 3 simple items. Thus, it is crucial to restrict distractor information from consuming VWM capacity. The current study investigated how VWM storage and distractor resistance develop during childhood in relation to academic performance in the classroom. Elementary school children (7- to 12-year-olds) and adults (total N = 140) completed a VWM task with and without visual/verbal distractors during the retention period. The results showed that VWM performance with and without distractors developed at similar rates until reaching adult levels at 10 years of age. In addition, higher VWM performance without distractors was associated with higher academic scores in literacy (reading and writing), mathematics, and science for the younger children (7- to 9-year-olds), whereas these academic scores for the older children (10- to 12 year-olds) were associated with VWM performance with visual distractors. Taken together, these results suggest that VWM storage and distractor resistance develop at a similar rate, whereas their contributions to academic performance differ with age. (C) 2016 Elsevier Inc. All rights reserved.

Empathy for social pain (e.g., that caused by social exclusion) may be crucial for social bonding because it allows to understand others' feeling and facilitate pro-social behavior such as consolation. Studies have indicated the relationship between personality traits and empathy for physical pain. However, few studies have addressed the personality traits that are related to empathy for social pain. The present study examined how personality traits would be related to social and physical empathy. Participants observed social exclusion (i.e., Cyberball movies) and photographs of painful situations of another person, which increased empathetic responses to the depicted person. The correlation analyses revealed that female participants with more extravert trait and/or more other-oriented feelings of sympathy and concern for unfortunate others tended to show greater empathy for physical pain. This result may suggest that attention toward other persons is a factor for physical empathy. Additionally, female participants with agreeableness trait tended to exhibit social empathy. Since agreeableness is related to general concern for social harmony, the tendency to avoid social conflicts may be related to social empathy.

It has been known that effects of visual attention are modulated by cue validity (i.e., proportion of valid and invalid condition in a certain block). The present study aimed at examining whether the benefits (i.e., the differences of reaction times in the valid and invalid condition) were linear as a function of cue reliability. We also examined effects of explicit instruction of information regarding cue reliability on visual attention. In the experiment, we adopted a cueing paradigm in which cue reliability varied in each block (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%). We also classified all participants into two groups: Instruction and Non-instruction groups. The results showed that the benefit was linear as a function of cue reliability regardless of instruction, which indicates that cue validity has a strong influence on visual attention compared to a cued location. We also found that reaction time in the valid condition became shorter with increased cue reliability compared to the invalid condition with decreased cue reliability, albeit only in the Instruction group. This result indicates that participants with instruction focus more on the cued location (i.e., valid condition) and not the dominant proportion of cue validity.

Identification and discrimination of peripheral stimuli are often difficult when a few stimuli adjacent to the target are present (crowding). Our previous study showed that crowding occurs for walking direction discrimination of a biological motion stimulus. In the present study, we attempted to examine whether action congruency between the target and flankers would influence the crowding effect on biological motion stimuli. Each biological motion stimulus comprised one action (e.g., walking, throwing wastepaper, etc.) and was rotated in one of five directions around the vertical axis. In Experiment 1, observers discriminated between the directions of the target stimulus actions, which were surrounded by two flankers in the peripheral visual field. The crowding effect was stronger when the flankers performed the same action as the target and the directions differed. The congruency of action type enhanced the crowding effect in the direction-discrimination task. In Experiment 2, observers discriminated between action types of target stimuli. The crowding effect for the action-discrimination task was not modulated by the congruency of action direction. Thus, identical actions induced a larger crowding effect for action-direction discrimination, but congruent directions did not influence crowding for action-type discrimination. These results suggest that the processes involved in direction discrimination of biological motion are partially distinct from action discrimination processes.

Latest research in robotics is driven by a desire to develop systems that would allow humans to interact with robots in natural and intuitive ways. In this paper we investigate peoples' initial believes, expectations and ascribed mental capabilities of a robot when they encounter it for the first time and how these change after interacting with the robot. The differences between two robots, which differ in morphology and behavior, are compared.

Prior results on the spatial integration of layouts within a room differed regarding the reference frame that participants used for integration. We asked whether these differences also occur when integrating 2D screen views and, if so, what the reasons for this might be. In four experiments we showed that integrating reference frames varied as a function of task familiarity combined with processing time, cues for spatial transformation, and information about action requirements paralleling results in the 3D case. Participants saw part of an object layout in screen 1, another part in screen 2, and reacted on the integrated layout in screen 3. Layout presentations between two screens coincided or differed in orientation. Aligning misaligned screens for integration is known to increase errors/latencies. The error/latency pattern was thus indicative of the reference frame used for integration. We showed that task familiarity combined with self-paced learning, visual updating, and knowing from where to act prioritized the integration within the reference frame of the initial presentation, which was updated later, and from where participants acted respectively. Participants also heavily relied on layout intrinsic frames. The results show how humans flexibly adjust their integration strategy to a wide variety of conditions.

Preferences for colors and geometric shapes vary considerably across individuals. Studies have demonstrated these variations in preference separately for colors and shapes, but the relationships between preference variations for colors and shapes are not yet known. By measuring individual preferences for basic colors and shapes, we found that color preferences and shape preferences were partly, but systematically, correlated. People who preferred some simple shapes (e.g., cone, pyramid) tended to prefer some light or warm colors (e.g., yellow, orange). In contrast, people who preferred some complex shapes (e.g., scrambled truncated-pyramid, scrambled pyramid) tended to prefer some dark or cold colors (e.g., blue, blue-green). That is, people who like simple or complex visual features might tend to like light or warm or dark or cold visual features. These results indicate that individual preferences for colors and shapes might not be independent, but could be correlated and intertwined to some extent. We suggest that the semantic information associated with colors and shapes underlies the cross preferences. (c) 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 188-195, 2016

© 2016 Chen, Tanaka, Namatame and Watanabe.Studies have contended that neurotypical Japanese individuals exhibit consistent color-shape associations (red-circle, yellow-triangle, and blue-square) and those color-shape associations could be constructed by common semantic information between colors and shapes through learning and/or language experiences. Here, we conducted two experiments using a direct questionnaire survey and an indirect behavioral test (Implicit Association Test), to examine whether the construction of color-shape associations entailed phonological information by comparing color-shape associations in deaf and hearing participants. The results of the direct questionnaire showed that deaf and hearing participants had similar patterns of color-shape associations (red-circle, yellow-triangle, and blue-square). However, deaf participants failed to show any facilitated processing of congruent pairs in the IAT tasks as hearing participants did. The present results suggest that color-shape associations in deaf participants may not be strong enough to be proved by the indirect behavior tasks and relatively weaker in comparison to hearing participants. Thus, phonological i

People maintain larger distances to other peoples' front than to their back. We investigated if humans also judge another person as closer when viewing their front than their back. Participants watched animated virtual characters (avatars) and moved a virtual plane toward their location after the avatar was removed. In Experiment 1, participants judged avatars, which were facing them as closer and made quicker estimates than to avatars looking away. In Experiment 2, avatars were rotated in 30 degree steps around the vertical axis. Observers judged avatars roughly facing them (i.e., looking max. 60 degrees away) as closer than avatars roughly looking away. No particular effect was observed for avatars directly facing and also gazing at the observer. We conclude that body orientation was sufficient to generate the asymmetry. Sensitivity of the orientation effect to gaze and to interpersonal distance would have suggested involvement of social processing, but this was not observed. We discuss social and lower-level processing as potential reasons for the effect.

The present study examined whether sequence learning led to more accurate and shorter performance time if people who are learning a sequence start over from the beginning when they make an error (i.e., practice the whole sequence) or only from the point of error (i.e., practice a part of the sequence). We used a visuomotor sequence learning paradigm with a trial-and-error procedure. In Experiment 1, we found fewer errors, and shorter performance time for those who restarted their performance from the beginning of the sequence as compared to those who restarted from the point at which an error occurred, indicating better learning of spatial and motor representations of the sequence. This might be because the learned elements were repeated when the next performance started over from the beginning. In subsequent experiments, we increased the occasions for the repetitions of learned elements by modulating the number of fresh start points in the sequence after errors. The results showed that fewer fresh start points were likely to lead to fewer errors and shorter performance time, indicating that the repetitions of learned elements enabled participants to develop stronger spatial and motor representations of the sequence. Thus, a single or two fresh start points in the sequence (i.e., starting over only from the beginning or from the beginning or midpoint of the sequence after errors) is likely to lead to more accurate and faster performance. (C) 2016 Elsevier B.V. All rights reserved.

We examined how the temporal and spatial predictability of a task irrelevant visual event affects the detection and memory of a visual item embedded in a continuously changing sequence. Participants observed 11 sequentially presented letters, during which a task-irrelevant visual event was either present or absent. Predictabilities of spatial location and temporal position of the event were controlled in 2 x 2 conditions. In the spatially predictable conditions, the event occurred at the same location within the stimulus sequence or at another location, while, in the spatially unpredictable conditions, it occurred at random locations. In the temporally predictable conditions, the event timing was fixed relative to the order of the letters, while in the temporally unpredictable condition; it could not be predicted from the letter order. Participants performed a working memory task and a target detection reaction time (PT) task. Memory accuracy was higher for a letter simultaneously presented at the same location as the event in the temporally unpredictable conditions, irrespective of the spatial predictability of the event. On the other hand, the detection RTs were only faster for a letter simultaneously presented at the same location as the event when the event was both temporally and spatially predictable. Thus, to facilitate ongoing detection processes, an event must be predictable both in space and time, while memory processes are enhanced by temporally unpredictable (i.e., surprising) events. Evidently, temporal predictability has differential effects on detection and memory of a visual item embedded in a sequence of images.

Numerical representations influence temporal processing. Previous studies have consistently shown that larger numbers are perceived to last longer than smaller ones. However, whether this effect is modulated by the absolute or relative magnitudes of the numbers has yet to be fully understood. Here, participants observed single-and double-digit Arabic numerals in separate experimental blocks and reproduced stimulus duration of 600 or 1200 ms. Our results replicated previous findings that the duration of larger numbers was reproduced longer than that of smaller numbers within each digit set. Although the effect of numerical magnitude across single-and double-digit numerals was found when the numerals were presented for 600 ms, the difference was negligible when they were presented for 1200 ms, suggesting that relative magnitude is an important factor in the number-time interaction in the suprasecond range. These results suggest that contextual influence on number-time interaction may depend on the actual stimulus duration.

It has been shown that positive emotions can facilitate integrative and associative information processing in cognitive functions. The present study examined whether emotions in observers can also enhance perceptual integrative processes. We tested 125 participants in total for revealing the effects of emotional states and traits in observers on the multisensory binding between auditory and visual signals. Participants in Experiment 1 observed two identical visual disks moving toward each other, coinciding, and moving away, presented with a brief sound. We found that for participants with lower depressive tendency, induced happy moods increased the width of the temporal binding window of the sound-induced bounce percept in the stream/bounce display, while no effect was found for the participants with higher depressive tendency. In contrast, no effect of mood was observed for a simple audiovisual simultaneity discrimination task in Experiment 2. These results provide the first empirical evidence of a dependency of multi sensory binding upon emotional states and traits, revealing that positive emotions can facilitate the multisensory binding processes at a perceptual level.

&lt;p&gt;In this study, the effects on concentration of attention, cognitive activity such as memory was examined in consideration of humans&#039; cognitive characteristic over 3D images about the partial 3D image which changed a part of picture. The experiment of concentration of attention was carried out by measuring reaction time in visual search task using a simple visual target and eye fixation while viewing natural color image. On the other hand, the experiment of cognitive effect such as memory, the searching time until the changes are recognized were computed using the change blindness subject. That needs the cognitive activity of comparing by memorizing a picture temporarily while turning a look for detection of change. As a result, it was suggested by the partial 3D image that an object has the cognitive effect which is easy to go up to consciousness and to remain in memory.&lt;/p&gt;

<p>In this research, the effects on preference and visual characteristics were examined on correlations with changing parallax angle conditions in stereoscopic 3D images. Specifically, we investigated the influence of their preference decisions in 2D and 3D conditions as well as the different type of parallax angle including the negative and positive parallaxes. In experiment 1, six novel shapes excluding humans' experience were presented with five types of parallax angles (-0.5, -0.2, 0, 0.2, 0.5 degree). The experiment of paired comparison which selected one from two shapes was conducted and eye movement was measured. As a result, the negative parallax type was preferable to the positive angle, which was influenced by the absolute value of the parallax angles. In experiment 2, the time and numbers of eye fixation were measured by eye movement analysis under the same stimuli and apparatus when performing paired comparison tasks with two types of parallax angles (-0.5 and 0.5 degree). The result was that the time and numbers of eye fixation more increased during viewing negative parallax conditions than positive one.</p>

It has been shown that human perception of robots changes after the first interaction. It is not clear, however, to which extent the robot's appearance and interactive abilities influences such changes in perception. In this paper, participants' perception of two robots with different appearance and interactive modalities are compared before and after a short interaction with the robots. Data from Japanese and Australian participants is evaluated and compared. Experimental results show significant differences in perception depending on the robot type and the time of interaction. As a result of cultural background, perception changes were observed only for Japanese participants on isolated key concepts.

Recent studies of cognitive science have convincingly demonstrated that human behavior, decision making and emotion depend heavily on “implicit mind,” that is, automatic, involuntary mental processes even the person herself/himself is not aware of. Such implicit processes may interact between partners, producing a kind of “resonance,” in which two or more bodies and brains, coupled via sensorimotor systems, act nearly as a single system. The basic concept of this project is that such “implicit interpersonal information (IIPI)” provides the basis for smooth and effective communication. We have been developing new methods to decode IIPI from brain activities, physiological responses, and body movements, and to control IIPI by sensorimotor stimulation and non-invasive brain stimulation. Here, we detail on two topics from the project, namely, interpersonal synchronization of involuntary body movements as IIPI, and autism as an impairment of IIPI. The findings of the project would provide guidelines for developing human-harmonized information systems.

In the present study, we investigated whether there were gender differences in visuo-motor sequence learning requiring trial-and-error process. In the task, participants learned correct button press orders of a given sequence by trial-and-error and successfully repeated the sequence for 20 trials. The results demonstrated that men showed more accurate and faster performance than women. The total number of errors until the 1st successful trial was fewer in men than in women while afterward, that was not different. The speed was faster in men than in women in the all performance phases. This result indicates that men could acquire spatial representations of button presses faster and do faster motor performance than women.

It has been known remembered locations of visual stimuli are systematically distorted in a two-dimensional (i.e., retinal) coordinate, which includes the foveal bias, memory averaging, and landmark effect. The present study aimed at examining how the remembered depth position of a visual target would be distorted. Also, we examined whether depth distortion would differ for perceptual and motor-related tasks. In the experiments, a visual target was presented for one second at various distances from the observers by using a 3D projector. The fixation distance was also varied. After the disappearance of the target, observers performed either perceptual judgment (the method of constant to estimate the point of psychological subjective equality) or motor response (by using a 3D mouse) for the remembered target distance. The results showed that the remembered depth of the target was compressed toward the averaged depth of the possible depth range for both perceptual and motor responses. In addition, however, the perceptual responses tended to overestimate the depth when the fixation depth was closer than or the same as the nearest possible depth of the target. No bias was observed when the fixation depth was farther than the nearest possible depth. For the motor responses, there was a general underestimation irrespective of fixation depth. These results suggest that spatial memory of depth for visual stimuli may be qualitatively different between perceptual and motor responses.

We explore whether expertise can modulate the capacity of visual short-term memory, as some seem to argue that training affects capacity of short-term memory [13] while others are not able to find this modulation [12]. We extend on a previous study [3] by demonstrating expertise effects by investigating different groups of healthy adults. In a whole report paradigm [5] we investigate performance on standardized pictures [11], Latin letters, and Japanese hiragana. Expertise was modulated between groups of novice (Danish university students), trained (Danish university students studying Japanese), and expert observers (Japanese university students). For both the picture and the letter condition we find no performance difference in memory capacity, however, in the critical hiragana condition we demonstrate a systematic difference relating expertise differences between the groups. These results are in line with the theoretical interpretation that visual short-term memory is the sum of the reverberating feedback loops to representations in long-term memory.

During first encounters and short-term interaction with robots, the robot's appearance and initial behavior plays a major role. In this paper we compare the outcome of three human-robot interaction studies using three different robot types in two different countries, Japan and Australia. The participants' perception of an android robot, a humanoid robot and a non-biomimetic robot are compared before and after interacting with the robots. The experimental results show significant differences in the way people perceive the robots based on appearance alone, and based on appearance and behavior after a short interaction.

Human visual system extracts or creates various rich information from low-level visual features. Animacy perception, where an obviously non-animate object elicits to us a feeling that the object is animate, is also susceptible to motion trajectory. For example, a simple dot, when moving with the random trajectory based on 1/f fluctuation, provide a vivid sensation of animacy. Recently, we found that perceived animacy from a randomly moving dot was drastically decreased by the presence of other dots that made synchronous motion with the target dot. However, in our previous study, the synchronous motion accompanied the spatial alignment, and hence it is unclear whether the synchronous motion per se or the spatial alignment is responsible for the modulation of animacy perception. The present study investigated the effects of these two factors by manipulating the spatial alignment independently from the motion synchrony. Consequently, we found that the reduction of perceived animacy from both spatially aligned as well as spatially misaligned synchronous motion, wherein the magnitudes of animacy reduction were quantitatively comparable. These results suggested that the synchronous motion is primal factor to reduce the perceived animacy, whereas the effect of spatial alignment was negligible.

In everyday life, navigators often consult a map before they navigate to a destination (e.g., a hotel, a room, etc.). However, not much is known about how humans gain spatial knowledge from seeing a map and direct navigation together. In the present experiments, participants learned a simple multiple corridor space either from a map only, only from walking through the virtual environment, first from the map and then from navigation, or first from navigation and then from the map. Afterwards, they conducted a pointing task from multiple body orientations to infer the underlying reference frames. We constructed the learning experiences in a way such that map-only learning and navigation-only learning triggered spatial memory organized along different reference frame orientations. When learning from maps before and during navigation, participants employed a map- rather than a navigation-based reference frame in the subsequent pointing task. Consequently, maps caused the employment of a map-oriented reference frame found in memory for highly familiar urban environments ruling out explanations from environmental structure or north preference. When learning from navigation first and then from the map, the pattern of results reversed and participants employed a navigation-based reference frame. The priority of learning order suggests that despite considerable difference between map and navigation learning participants did not use the more salient or in general more useful information, but relied on the reference frame established first.

This study focuses on differences and similarities of perception of a small humanoid robot between Japanese and Australian participants. Two conditions were investigated: participants actively interacting with the robot and bystanders observing the interaction. Experimental results suggested that, while the robot was perceived as highly likeable, Japanese participants rated the robot higher for animacy, intelligence and safety. Furthermore, passive observations of the interaction (rather than active interaction) resulted in higher ratings by Japanese participants for anthropomorphism, animacy, intelligence and safety. The findings are discussed in terms of cultural background and robot perception.

Implicit learning and transfer in sequence acquisition play important roles in daily life. Several previous studies have found that even when participants are not aware that a transfer sequence has been transformed from the learning sequence, they are able to perform the transfer sequence faster and more accurately
this suggests implicit transfer of visuomotor sequences. Here, we investigated whether implicit transfer could be modulated by the number of trials completed in a learning session. Participants learned a sequence through trial and error, known as the m × n task (Hikosaka et al. in J Neurophysiol 74:1652–1661, 1995). In the learning session, participants were required to successfully perform the same sequence 4, 12, 16, or 20 times. In the transfer session, participants then learned one of two other sequences: one where the button configuration Vertically Mirrored the learning sequence, or a randomly generated sequence. Our results show that even when participants did not notice the alternation rule (i.e., vertical mirroring), their total working time was less and their total number of errors was lower in the transfer session compared with those who performed a Random sequence, irrespective of the number of trials completed in the learning session. This result suggests that implicit transfer likely occurs even over a shorter learning duration.

Implicit learning and transfer in sequence acquisition play important roles in daily life. Several previous studies have found that even when participants are not aware that a transfer sequence has been transformed from the learning sequence, they are able to perform the transfer sequence faster and more accurately; this suggests implicit transfer of visuomotor sequences. Here, we investigated whether implicit transfer could be modulated by the number of trials completed in a learning session. Participants learned a sequence through trial and error, known as the m x n task (Hikosaka et al. in J Neurophysiol 74:1652-1661, 1995). In the learning session, participants were required to successfully perform the same sequence 4, 12, 16, or 20 times. In the transfer session, participants then learned one of two other sequences: one where the button configuration Vertically Mirrored the learning sequence, or a randomly generated sequence. Our results show that even when participants did not notice the alternation rule (i.e., vertical mirroring), their total working time was less and their total number of errors was lower in the transfer session compared with those who performed a Random sequence, irrespective of the number of trials completed in the learning session. This result suggests that implicit transfer likely occurs even over a shorter learning duration.

Wisdom computing and harmonious collaborations between humans and machines require understanding of both explicit and implicit aspects of embodied or tacit knowledge. We propose that scientific and technological advances on "Implicit Ambient Surface Information" are vital for further development of wisdom computing. This is based on the notion that information on the agent's (e.g., bodies and machine) surfaces is implicitly processed and affects collaborations between agents. For this, truly wearable devices that do not interfere with users activates are warranted. We have started to examine the potential use of implicit ambient surface information in the field of sports. Scientific and technological advances on such information will provide an innovative venue for wisdom computing and harmonious collaborations between humans and machines.

In the uncanny valley phenomenon, the causes of the feeling of uncanniness as well as the impact of the uncanniness on behavioral performances still remain open. The present study investigated the behavioral effects of stimulus uncanniness, particularly with respect to speeded response. Pictures of fish were used as visual stimuli. Participants engaged in direction discrimination, spatial cueing, and dot-probe tasks. The results showed that pictures rated as strongly uncanny delayed speeded response in the discrimination of the direction of the fish. In the cueing experiment, where a fish served as a task-irrelevant and unpredictable cue for a peripheral target, we again observed that the detection of a target was slowed when the cue was an uncanny fish. Conversely, the dot-probe task suggested that uncanny fish, unlike threatening stimulus, did not capture visual spatial attention. These results suggested that stimulus uncanniness resulted in the delayed response, and importantly this modulation was not mediated by the feelings of threat.

In interpreting verbal messages, humans use not only verbal information but also nonverbal signals such as facial expression. For example, when a person says "yes" with a troubled face, what he or she really means appears ambiguous. In the present study, we examined how deaf and hearing people differ in perceiving real meanings in texts accompanied by representations of facial expression. Deaf and hearing participants were asked to imagine that the face presented on the computer monitor was asked a question from another person (e.g., do you like her?). They observed either a realistic or a schematic face with a different magnitude of positive or negative expression on a computer monitor. A balloon that contained either a positive or negative text response to the question appeared at the same time as the face. Then, participants rated how much the individual on the monitor really meant it (i.e., perceived earnestness), using a 7-point scale. Results showed that the facial expression significantly modulated the perceived earnestness. The influence of positive expression on negative text responses was relatively weaker than that of negative expression on positive responses (i.e., "no" tended to mean "no" irrespective of facial expression) for both participant groups. However, this asymmetrical effect was stronger in the hearing group. These results suggest that the contribution of facial expression in perceiving real meanings from text messages is qualitatively similar but quantitatively different between deaf and hearing people.

Albertazzi et al. (2013) showed naturally biased associations between geometric shapes and colors in Italian participants, suggesting that the "warmth" and "lightness" of color might account for the color-shape associations. In the present study, we replicated the previous study in Japanese participants to examine whether color-shape associations were unlikely influenced by differences between languages and cultures. Results showed that Japanese participants associated shapes with specific colors, and these color-shape associations, by and large, were consistent with those in the previous literature. In addition, correspondence analysis indicated that most of the color-shape associations could be interpreted by congruent "warmth" perception for colors and shapes. Therefore, semantic associations between visual features of color and shape might lead to the color-shape associations.

The face is a special visual stimulus. Both bottom-up processes for low-level facial features and top-down modulation by face expectations contribute to the advantages of face perception. However, it is hard to dissociate the top-down factors from the bottom-up processes, since facial stimuli mandatorily lead to face awareness. In the present study, using the face pareidolia phenomenon, we demonstrated that face awareness, namely seeing an object as a face, enhances object detection performance. In face pareidolia, some people see a visual stimulus, for example, three dots arranged in V shape, as a face, while others do not. This phenomenon allows us to investigate the effect of face awareness leaving the stimulus per se unchanged. Participants were asked to detect a face target or a triangle target. While target per se was identical between the two tasks, the detection sensitivity was higher when the participants recognized the target as a face. This was the case irrespective of the stimulus eccentricity or the vertical orientation of the stimulus. These results demonstrate that seeing an object as a face facilitates object detection via top-down modulation. The advantages of face perception are, therefore, at least partly, due to face awareness.

This study contained two experimental examinations of the cognitive activities such as visual attention and memory in viewing stereoscopic (3D) images. For this study, partially converted 3D images were used with binocular parallax added to a specific region of the image. In Experiment 1, change blindness was used as a presented stimulus. The visual attention and impact on memory were investigated by measuring the response time to accomplish the given task. In the change blindness task, an 80 ms blank was intersected between the original and altered images, and the two images were presented alternatingly for 240 ms each. Subjects were asked to temporarily memorize the two switching images and to compare them, visually recognizing the difference between the two. The stimuli for four conditions (2D, 3D, Partially converted 3D, distracted partially converted 3D) were randomly displayed for 20 subjects. The results of Experiment 1 showed that partially converted 3D images tend to attract visual attention and are prone to remain in viewer's memory in the area where moderate negative parallax has been added.
In order to examine the impact of a dynamic binocular disparity on partially converted 3D images, an evaluation experiment was conducted that applied learning, distraction, and recognition tasks for 33 subjects. The learning task involved memorizing the location of cells in a 5 x 5 matrix pattern using two different colors. Two cells were positioned with alternating colors, and one of the gray cells was moved up, down, left, or right by one cell width. Experimental conditions was set as a partially converted 3D condition in which a gray cell moved diagonally for a certain period of time with a dynamic binocular disparity added, a 3D condition in which binocular disparity was added to all gray cells, and a 2D condition. The correct response rates for recognition of each task after the distraction task were compared. The results of Experiment 2 showed that the correct response rate in the partial 3D condition was significantly higher with the recognition task than in the other conditions. These results showed that partially converted 3D images tended to have a visual attraction and affect viewer's memory.

Mirror symmetry is known as a special case of symmetric patterns because of its superior detectability. This study examined whether the perceptual advantage of mirror symmetry is maintained despite the absence of perfect symmetry. We manipulated the alignment of symmetric patterns by adding a vertical offset between left and right halves of them. We found that regularity of mirror symmetry was better detectable than that of translational symmetry in the aligned display. However, the advantage of mirror symmetry disappeared even with the smallest misalignment used in the present study. These results suggest that global configuration of pattern elements plays an important role in mirror symmetry detection.

Chen et al (In prepare) found that deaf people have established similar pattern of color-shape associations with hearing people, such as circle-red, triangle-yellow, and square-blue links. This result indicated that phonological information might have little effect on color-shape associations. However, the strength and consistency of color-shape associations in deaf people is currently unknown. In the present study, we examined the consistency of color-shape associations over a span of time in deaf people. Results showed that deaf people's color-shape associations (e.g., circle-red) were consistent and stable over time. Those results might provide further support for semantic sensory correspondence between colors and shapes.

The curtate cycloid illusion is an illusory perception where a cycloidal trajectory is perceived as curtate cycloid. Previous studies imply that this illusory perception occurs because we could fail to process two motion components (rotation and translation) simultaneously, and this particularly occurs at the instant center of the wheel's rotation. The present study examined the factors of the curtate cycloid illusion by decomposing the wheel's center and rim, where the former causes the vector decomposition of the rotation and translation motion and the latter creates an instant center on a rolling wheel. The results showed that the vector decomposition caused a strong bias in the perception of the trajectory toward a curtate cycloid, while adding an instant center did caused such a bias, but rather caused difficulty in the trajectory perception. These results indicate that the curtate cycloid illusion could occur when a point moving along a cycloidal (or prorate cycloidal) trajectory is perceptually decomposed into its rotational and translational motions by seen as moving relative to a common reference frame with a rectilinearly moving object (e.g., the hub of a wheel).

Kandinsky proposed a correspondence theory that suggests associations between specific colors and shapes (i.e., circle-blue, square-red, triangle-yellow). Makin and Wuerger tested the theory using the Implicit Association Test (IAT) and did not find clear evidence for Kandinsky's color-shape associations among British participants. In the present study, we first replicated the previous study among Japanese participants and found similar results to those of Makin and Wuerger, showing little support for Kandinsky's theory. In the subsequent experiment, we tested another set of color-shape associations that had been revealed by using an explicit matching method (circle-red, square-blue, triangle-yellow) in Japanese participants. The IAT tests showed that response times were significantly faster when circle-red, square-blue, and triangle-yellow combinations were mapped onto the same response key, rather than different key combinations, indicating that these colorshape combinations were encoded. These results provide the first empirical evidence that color-shape associations can be measured by indirect behavioral methods, and in particular, Japanese people's color-shape associations (circle-red, square-blue, triangle-yellow) can be observed by both direct and indirect experimental methods.

The phonological abilities of congenitally deaf individuals are inferior to those of people who can hear. However, deaf individuals can acquire spoken languages by utilizing orthography and lip-reading. The present study used functional magnetic resonance imaging (fMRI) to show that deaf individuals utilize phonological representations via a mnemonic process. We compared the brain activation of deaf and hearing participants while they memorized serially visually presented Japanese kana letters (Kana), finger alphabets (Finger), and Arabic letters (Arabic). Hearing participants did not know which finger alphabets corresponded to which language sounds, whereas deaf participants did. All of the participants understood the correspondence between Kana and their language sounds. None of the participants knew the correspondence between Arabic and their language sounds, so this condition was used as a baseline. We found that the left superior temporal gyrus (STG) was activated by phonological representations in the deaf group when memorizing both Kana and Finger. Additionaly, the brain areas associated with phonological representations for Finger in the deaf group were the same as the areas for Kana in the hearing group. Overall, despite the fact that they are superior in visual information processing, deaf individuals utilize phonological rather than visual representations in visually presented verbal memory. (C) 2014 Published by Elsevier Ireland Ltd.

Visual motion serves as a cue for high-level percepts. The present study reports novel modulation of animacy perception through synchronous motion. A target dot moving along a random trajectory was presented. The trajectory was generated based on a variant of 1/f noise; hence, the dot could be perceived as animate. Participants were asked to rate the strength of perceived animacy and perceived intention from the target dot. Several task-irrelevant dots surrounding the target were also presented. Results indicated that perceived animacy and intention were drastically weakened when surrounding dots created synchronous motion with the target dot as compared to when surrounding dots did not create synchronous motion. A series of follow-up experiments replicated these results and revealed specific characteristics of this modulation. The present findings suggest synchronous visual motion serves as a strong modulator of animacy perception.

The present study examined whether different depth cues would interact with the judgment of density differently. Using a 3D projector, we presented random-dot stimuli on fronto-parallel square planes at different depths (-30, 15, 0, +15, or +30 cm from the projection plane) and measured the perceived density of the dots in each depth plane using the method of constant stimuli. The depth of the plane was manipulated with three types of depth cues (binocular disparity, stimulus area, and dot size), which were used separately or all together. The results showed that the averaged PSEs depended on the depth plane when the depth cue was stimulus area, whereas the influences of size and disparity cues on the PSE were relatively weak. However, when the cues were combined, the influence of the area cue on density judgment was largely attenuated. These findings imply that the combination of the depth cues can provide more precise depth perception of the dots and helping interpretations of "3D-valid density".

Implicit learning and transfer in sequence learning are essential in daily life. Here, we investigated the implicit transfer of visuomotor sequences following a spatial transformation. In the two experiments, participants used trial and error to learn a sequence consisting of several button presses, known as the m x n task (Hikosaka et al., 1995). After this learning session, participants learned another sequence in which the button configuration was spatially transformed in one of the following ways: mirrored, rotated, and random arrangement. Our results showed that even when participants were unaware of the transformation rules, accuracy of transfer session in the mirrored and rotated groups was higher than that in the random group (i.e., implicit transfer occurred). Both those who noticed the transformation rules and those who did not (i.e., explicit and implicit transfer instances, respectively) showed faster performance in the mirrored sequences than in the rotated sequences. Taken together, the present results suggest that people can use their implicit visuomotor knowledge to spatially transform sequences and that implicit transfers are modulated by a transformation cost, similar to that in explicit transfer. (c) 2014 Elsevier B.V. All rights reserved.

The saccadic latency to visual targets is susceptible to the properties of the currently fixated objects. For example, the disappearance of a fixation stimulus prior to presentation of a peripheral target shortens saccadic latencies (the gap effect). In the present study, we investigated the influences of a social signal from a facial fixation stimulus (i.e., gaze direction) on subsequent saccadic responses in the gap paradigm. In Experiment 1, a cartoon face with a direct or averted gaze was used as a fixation stimulus. The pupils of the face were unchanged (overlap), disappeared (gap), or were translated vertically to make or break eye contact (gaze shift). Participants were required to make a saccade toward a target to the left or the right of the fixation stimulus as quickly as possible. The results showed that the gaze direction influenced saccadic latencies only in the gaze shift condition, but not in the gap or overlap condition; the direct-to-averted gaze shift (i.e., breaking eye contact) yielded shorter saccadic latencies than did the averted-to-direct gaze shift (i.e., making eye contact). Further experiments revealed that this effect was eye contact specific (Exp. 2) and that the appearance of an eye gaze immediately before the saccade initiation also influenced the saccadic latency, depending on the gaze direction (Exp. 3). These results suggest that the latency of target-elicited saccades can be modulated not only by physical changes of the fixation stimulus, as has been seen in the conventional gap effect, but also by a social signal from the attended fixation stimulus.

Application of graph theory to analysis of functional networks in the brain is an important research trend. Extensive research on the resting state has shown a "small-world" organization of the brain network as a whole. However, the small-worldness of children's brain networks in a working state has not yet been well characterized. In this paper, we used a custom-made, child-sized magnetoencephalography (MEG) device to collect data from children while they were watching cartoon videos. Network structures were analyzed and compared with scores on the Kaufman Assessment Battery for Children (K-ABC). The results of network analysis showed that (1) the small-world scalar showed a negative correlation with the simultaneous processing raw score, a measure of visual processing (Gv) ability, and (2) the children with higher simultaneous processing raw scores possessed network structures that can be more efficient for local information processing than children with lower scores. These results were compatible with previous studies on the adult working state. Additional results obtained from further analysis of the frontal and occipital lobes indicated that high cognitive performance could represent better local efficiency in task-related sub-networks. Under free viewing of cartoon videos, brain networks were no longer confined to their strongest small-world states; connections became clustered in local areas such as the frontal and occipital lobes, which might be a more useful configuration for handling visual processing tasks. (C) 2014 Elsevier Inc. All rights reserved.

Some spatio-temporal structures are easier to transfer implicitly in sequential learning. In this study, we investigated whether the consistent reversal of triads of learned components would support the implicit transfer of their temporal structure in visuomotor sequence learning. A triad comprised three sequential button presses ([1][2][3]) and seven consecutive triads comprised a sequence. Participants learned sequences by trial and error, until they could complete it 20 times without error. Then, they learned another sequence, in which each triad was reversed ([3][2][1]), partially reversed ([2][1][3]), or switched so as not to overlap with the other conditions ([2][3][1] or [3][1][2]). Even when the participants did not notice the alternation rule, the consistent reversal of the temporal structure of each triad led to better implicit transfer; this was confirmed in a subsequent experiment. These results suggest that the implicit transfer of the temporal structure of a learned sequence can be influenced by both the structure and consistency of the change.

Despite the emphasis of autism spectrum disorders as a continuum of atypical social behaviors and the sexual heterogeneity of phenotypic manifestations, whether gaze processing constitutes an autistic endophenotype in both sexes remains unclear. Using the Autism-Spectrum Quotient and a psychophysical approach in a normal population (N = 128), here we demonstrated that individual differences in autistic traits predicted direct-gaze perception for males, but not for females. Our findings suggest that direct-gaze perception may not constitute an autistic endophenotype in both sexes, and highlight the importance of sex differences when considering relationships between autistic traits and behaviors.

In the present study, we aimed at investigating possible similarities (and discrepancies) between two major machine algorithms of face detection (AdaBoost and EigenFace) and human face detection processes. For this, we presented the "false classification images" produced by the two face detection algorithms to human observers. Noise fields were fed into the two algorithms and images in which each algorithm falsely detected faces were collected. Those images were averaged and normalized to obtain false classification images. Human observers performed a psychophysical experiment to detect a face with the false classification images against random noise images. The face detection performance increased almost linearly as the number of averaged false detection images increase. Inverted images reduced the detection performance more with the images produced by EigenFace than those by AdaBoost. The present results suggest that both human and machine detection algorithms tended to make similar errors and therefore both AdaBoost and EigenFace are good approximation of human face processing.

Human facial attractiveness plays an important role in social decisions, e. g., mate choices. Researches have investigated gender difference on facial attractiveness perception, both in terms of the target face and the evaluators and have revealed the difference in facial features that influence attractiveness evaluation of male faces and female faces. In addition, fluctuations of female's preference on facial attractiveness evaluation of male faces have been reported. Our motivation for the current study was along the same line with this gender difference, but particularly focusing on the individual variety of evaluating facial attractiveness in female evaluators. The results showed that, while overall average patterns in attractiveness ratings were similar in evaluating male and female faces, more inter-evaluator diversity was found when the female evaluators rated more attractive male faces but not for female faces. These findings support the literature indicating the presence of deferential processes for face attractiveness evaluations of female and male faces.

Visual attractiveness has significant effects on our social life. People make up one's appearance by clothing, wearing accessories, applying cosmetics, hair-style and hair-color, etc., to convey certain impressions including attractiveness to others. In this study, we examined (a) how the suitability between face and hair color (i.e., hair-color matching) would be evaluated by oneself and by others and (b) how the hair-color matching would interact with perceived attractiveness. We found that 1) different criteria were used for hair-color matching between self-evaluation and evaluation by others, and 2) a wider range of hair-colors matched to the face, when the face was evaluated as more attractive and/or the perceived facial makeup was more. These results suggest that the evaluation of hair-color suitability might differ in self-evaluation and in evaluation by others, and suitability of hair-color has a certain interaction with perceived facial attractiveness. Possible implications are also discussed.

Some human brain functions are known to be lateralized to the left or right hemisphere. Although the perception of face has been shown to be mediated by the right hemisphere, whether the discrimination of eye gaze is also mediated by the right hemisphere remains uncertain. In the present study, we attempt to investigate whether the discrimination of human gaze direction is different between the left and right hemispheres. Participants performed a discrimination task using face images in which the face image with gaze was briefly displayed either in the left or right visual hemifield. We found that the discrimination performance of direct gaze was superior to that of averted gaze in the right hemifield when the face image without gaze (control stimulus) was presented in the opposite hemifield. However, the discrimination performance of direct and averted gaze was comparable in the left hemifield. Our findings may reflect a humans' implicit expectation that gaze is directed toward them when the perception of gaze is difficult, which stems from relative difficulty in processing gaze in the non-dominant left hemisphere.

Some products are explicitly or implicitly designed so that objects can be seen as a face; this will possibly support a fluent human-environment communication. The present study investigated the effects of seeing objects as face on human's visual search performance by means of psychological experiments. The participants were asked to search a target among distractors on a computer display as quickly as possible. The target and distractors differed in the vertical direction. The participants were randomly assigned to a face task or a triangle task. In the face task, the visual stimulus was either a cartoon face or three dots arranged in triangle that could be seen as a face, and the participants were instructed to search a upright or inverted face among distractors. In the triangle task, the visual stimulus was either the three dots same as the face task or a line-drawing triangle, and the participants were instructed to search a triangle. In both tasks, two types of stimuli were randomly presented during the trial sequence. We found that visual search for the three-dot target was slower in the face task than in the triangle task. However, when the target stimulus was informed immediately before each trial, the results were reversed; visual search for the three-dot target in the face task was faster than in the triangle task. These results suggest that, even if the target stimulus par se is identical, seeing the target as face modulates visual search performance, and the effects interact with expectation or preparation of the subsequent target.

A brief visual stimulus distorts the perceived shape of a subsequent visual stimulus as being dissimilar to the shape of a previous stimulus (shape-contrast effect). In this study, we presented a visual stimulus after a to-be-estimated target stimulus and found that the perceived shape of the target stimulus appeared to be similar to the shape of the following stimulus (shape-assimilation effect). The assimilation effect occurred even when the following stimulus was presented at positions different from that of the target stimulus, indicating that the shape-assimilation effect is a nonretinotopic distortion. The results suggest that the preceding and succeeding stimuli differentially modulate the perceived shape of a briefly presented stimulus.

Saccadic and manual reactions to a peripherally presented target are facilitated by removing a central fixation stimulus shortly before a target onset (the gap effect). The present study examined the effects of removal of a visible and invisible fixation point on the saccadic gap effect and the manual gap effect. Participants were required to fixate a central fixation point and respond to a peripherally presented target as quickly and accurately as possible by making a saccade (Experiment 1) or pressing a corresponding key (Experiment 2). The fixation point was dichoptically presented, and visibility was manipulated by using binocular rivalry and continuous flash suppression technique. In both saccade and key-press tasks, removing the visible fixation strongly quickened the responses. Furthermore, the invisible fixation, which remained on the display but suppressed, significantly delayed the saccadic response. Contrarily, the invisible fixation had no effect on the manual task. These results indicate that partially different processes mediate the saccadic gap effect and the manual gap effect. In particular, unconscious processes might modulate an oculomotor-specific component of the saccadic gap effect, presumably via subcortical mechanisms.

Although personal liking varies considerably, there is a general trend of liking shared by many people (public favour). Visual liking in particular may be largely shared by people, as it is strongly influenced by relatively low-level perceptual factors. If so, it is likely that people have correct knowledge of public favour. We examined the human ability to predict public favour. In three experiments, participants rated the subjective likability of various visual objects (e. g. car, chair), and predicted the mean liking rating by other participants. Irrespective of the object's category, the correlation between individual prediction and actual mean liking of others (prediction validity) was not higher than the correlation between the predictor's own liking and the mean liking of others. Further, individual prediction correlated more with the predictor's own liking than it was with others' liking. Namely, predictions were biased towards the predictor's subjective liking (a variation of the false consensus effect). The results suggest that humans do not have (or cannot access) correct knowledge of public favour. It was suggested that increasing the number of predictors is the appropriate strategy for making a good prediction of public favour.

Recent studies have showed that color-shape associations would be likely immune against cultural background and could be interpreted by congruent semantic information of warmth perception. Nevertheless, effects of phonological character of shapes and colors on color-shape associations were unclear. Therefore, in the present study, we compared color-shape associations in deaf and hearing participants. Result showed that deaf participants probably shared consistent color-shape associations with hearing participants, which indicated that the phonological character of shapes and colors would have little effect on color-shape associations and supported the previous findings.

We investigated the effect of background scene on the human visual perception of depth orientation (i.e., azimuth angle) of three-dimensional common objects. Participants evaluated the depth orientation of objects. The objects were surrounded by scenes with an apparent axis of the global reference frame, such as a sidewalk scene. When a scene axis was slightly misaligned with the gaze line, object orientation perception was biased, as if the gaze line had been assimilated into the scene axis (Experiment 1). When the scene axis was slightly misaligned with the object, evaluated object orientation was biased, as if it had been assimilated into the scene axis (Experiment 2). This assimilation may be due to confusion between the orientation of the scene and object axes (Experiment 3). Thus, the global reference frame may influence object orientation perception when its orientation is similar to that of the gaze-line or object.

Objective: We aimed to investigate how ordered mappings (e.g., left-to-right and right-to-left order representations) would interfere with each other.
Background: Mental representations of numbers and letters are linked with spatial representation and can be changed intentionally.
Method: The experiment consisted of three sessions. In the digit-alone session, two digits randomly selected from [1], [2], and [3] were shown. If the two digits were the same, participants pressed the button corresponding to the digit, and if the digits differed, they pressed the remaining button. The response buttons were ordered [1][2][3] from the left. In the letter-alone session, three different button configurations were prepared: sequential [A][B][C], reversed [C][B][A], or partially reversed [B][A][C]. The same-versus-different rules were basically identical to those in the digit task. In the mixed session, trials of the digit task and those of the letter task were randomly mixed.
Results: We found that two ordinal representations did not interfere with each other when they shared the same direction of order ([1][2][3] vs. [A][B][C]), two ordinal mappings interfered with each other when they had different directions of order ([1][2][3] vs. [C][B][A]), and an ordinal mapping ([1][2][3]) was affected by a nonordinal mapping ([B][A][C]), but the nonordinal mapping was less affected by the ordinal mapping.
Conclusion: The mapping between ordinal information and space can be modulated by top-down processes, and it is prone to interference depending on the nature of another coexisting mapping.
Application: Our findings may be used in designing response assignments for input devices for multiple functions.

When a visual object is briefly flashed, it appears to lag behind another moving object (flash-lag effect; FLE). Previous studies showed that a sudden change to the moving object at the time of the flash presentation would eliminate the FLE. We examined whether the FLE would be eliminated when a sudden color change was embedded in a sequence of color alternations on a moving object. Observers viewed a moving disc, the color of which did not change at all, changed only once when another stationary object flashed, or alternated regularly (Experiment 1) or randomly (Experiment 2) between two colors as it was moving before the flash presentation. Although the magnitude was reduced compared with the no-change condition, the FLE observed with the moving object that changed color during motion was significantly stronger than that in the one-change condition. In Experiment 3, the object color alternated between two but unexpectedly changed to a new color when the flash appeared. The elimination of FLE in such condition was comparable to the one-change condition, suggesting that the unexpected change restored the salience of the moving object at the time of flash presentation, which spared the observer from perceiving the FLE. We propose that, without an unexpected event, rapid changes in the surface feature of the moving object partially degrade the maintenance of object file, but this does not preclude the visual system in registering the existence of only one object in the motion stream. (C) 2013 Elsevier Ltd. All rights reserved.

Responses in a current trial are biased by the stimulus and response in the preceding trial. In a mixed-category sequence, the sequential dependency is weaker when the stimuli of the current and preceding trials fall under different categories. In the present study, we investigated the influence of the gender membership of faces on the sequential dependency. Forty-eight pictures of male and female faces were presented successively. Participants rated the attractiveness, roundness, or intelligence of each face on a 7-point scale. The sequential effect was robustly observed, irrespective of the property to be judged. However, between-gender sequential dependency was weaker than within-gender dependency only in the attractiveness judgment. These findings suggest that the gender of faces serves as a cue for forming category representations when face attractiveness is of interest, and hence that the formation of categories in sequential decisions is an adaptive process that depends on the property to be judged.

Studies of embodied perception have revealed that social, psychological, and physiological factors influence space perception. While many of these influences were observed with real or highly realistic stimuli, the present work showed that even the orientation of abstract geometric objects in a non-realistic virtual environment could influence distance perception. Observers wore a head mounted display and watched virtual cones moving within an invisible cube for 5 s with their head movement recorded. Subsequently, the observers estimated the distance to the cones or evaluated their friendliness. The cones either faced the observer, a target behind the cones, or were oriented randomly. The average viewing distance to the cones varied between 1.2 and 2.0 m. At a viewing distance of 1.6 m, the observers perceived the cones facing them as closer than the cones facing a target in the opposite direction, or those oriented randomly. Furthermore, irrespective of the viewing distance, observers moved their head away from the cones more strongly and evaluated the cones as less friendly when the cones faced the observers. Similar distance estimation results were obtained with a 3-dimensional projection onto a large screen, although the effective viewing distances were farther away. These results suggest that factors other than physical distance influenced distance perception even with non-realistic geometric objects in a virtual environment. Furthermore, the distance perception modulation was accompanied by changes in subjective impression and avoidance movement. We propose that cones facing an observer are perceived as socially discomforting or threatening, and potentially violate an observer's personal space, which might influence the perceived distance of cones.

Intervals between stimuli and/or responses have significant influences on sequential learning. In the present study, we investigated whether transfer would occur even when the intervals and the visual configurations in a sequence were drastically changed so that participants did not notice that the required sequences of responses were identical. In the experiment, two (or three) sequential button presses comprised a "set," and nine (or six) consecutive sets comprised a "hyperset." In the first session, participants learned either a 2 x 9 or 3 x 6 hyperset by trial and error until they completed it 20 times without error. In the second block, the 2 x 9 (3 x 6) hyperset was changed into the 3 x 6 (2 x 9) hyperset, resulting in different visual configurations and intervals between stimuli and responses. Participants were assigned into two groups: the Identical and Random groups. In the Identical group, the sequence (i.e., the buttons to be pressed) in the second block was identical to that in the first block. In the Random group, a new hyperset was learned. Even in the Identical group, no participants noticed that the sequences were identical. Nevertheless, a significant transfer of performance occurred. However, in the subsequent experiment that did not require explicit trial-and-error learning in the first session, implicit transfer in the second session did not occur. These results indicate that learning with explicit elaboration strengthens the implicit representation of the sequence order as a whole; this might occur independently of the intervals between elements and enable implicit transfer.

Recent studies suggest that action video game players exhibit superior performance in visuospatial cognitive tasks compared with non-game players. However, the neural basis underlying this visuospatial cognitive performance advantage remains largely unknown. The present human behavioral and imaging study compared gray matter volume in action video game experts and non-experts using structural magnetic resonance imaging and voxel-based morphometry analysis. The results revealed significantly larger gray matter volume in the right posterior parietal cortex in experts compared with non-experts. Furthermore, the larger gray matter volume in the right posterior parietal cortex significantly correlated with individual performance in a visual working memory task in experts. These results suggest that differences in brain structure may be linked to extensive video game play, leading to superior visuospatial cognitive performance in action video game experts. © 2013 Tanaka et al.

The saccadic "gap effect" refers to a phenomenon whereby saccadic reaction times (SRTs) are shortened by the removal of a visual fixation stimulus prior to target presentation. In the current study, we investigated whether the gap effect was influenced by retinal input of a fixation stimulus, as well as phenomenal permanence and/or expectation of the re-emergence of a fixation stimulus. In Experiment 1, we used an occluded fixation stimulus that was gradually hidden by a moving plate prior to the target presentation, which produced the impression that the fixation stimulus still remained and would reappear from behind the plate. We found that the gap effect was significantly weakened with the occluded fixation stimulus. However, the SRT with the occluded fixation stimulus was still shorter in comparison to when the fixation stimulus physically remained on the screen. In Experiment 2, we investigated whether this effect was due to phenomenal maintenance or expectation of the reappearance of the fixation stimulus; this was achieved by using occluding plates that were an identical color to the background screen, giving the impression of reappearance of the fixation stimulus but not of its maintenance. The result showed that the gap effect was still weakened by the same degree even without phenomenal maintenance of the fixation stimulus. These results suggest that the saccadic gap effect is modulated by both retinal input and subjective expectation of re-emergence of the fixation stimulus. In addition to oculomotor mechanisms, other components, such as attentional mechanisms, likely contribute to facilitation of the subsequent action. (c) 2013 Elsevier Ltd. All rights reserved.

Information received from different sensory modalities profoundly influences human perception. For example, changes in the auditory flutter rate induce changes in the apparent flicker rate of a flashing light (Shipley, 1964). In the present study, we investigated whether auditory information would affect the perceived offset position of a moving object. In Experiment 1, a visual object moved toward the center of the computer screen and disappeared abruptly. A transient auditory signal was presented at different times relative to the moment when the object disappeared. The results showed that if the auditory signal was presented before the abrupt offset of the moving object, the perceived final position was shifted backward, implying that the perceived visual offset position was affected by the transient auditory information. In Experiment 2, we presented the transient auditory signal to either the left or the right ear. The results showed that the perceived visual offset shifted backward more strongly when the auditory signal was presented to the same side from which the moving object originated. In Experiment 3, we found that the perceived timing of the visual offset was not affected by the spatial relation between the auditory signal and the visual offset. The present results are interpreted as indicating that an auditory signal may influence the offset position of a moving object through both spatial and temporal processes.

Impression managements with fashion, cosmetics, hairstyle and hair-color etc. are omnipresent. Matching to the self-concept is the primary factor in impression managements. In the current research, we examined how hair-color matching evaluation would correlate with one's intended impressions to others and how the matching of hair-color might affect the self-perception in Japanese women. Results indicated that: 1) Hair-color matching evaluation by oneself was related to the one's intended impressions. 2) The colors that were thought to be matched to oneself were evaluated as socially desirable and interpersonally likeable. Thus, Japanese women want to make them appear "socially acceptable" and it is an important criterion for hair-color matching evaluation. This is consistent with the idea that motivation of managing impressions is to convey one's social roles in communities. © 2013 IEEE.

Future standardized system for distinguishing actual and artifactual magnetoencephalogram (MEG) data is an essential tool. In this paper, we proposed the quantitative parameters based on fractal dimension (FD) analyses in which the FD may convey different features before and after artifact removal. The six FD algorithms based on time-series computation, namely, box-counting method (BCM), variance fractal dimension (VFD), Higuchi's method (HM), Kazt's method (KM), detrended fluctuation analysis (DFA), and modified zero-crossing rate (MZCR) were compared. These approaches measure nonlinear-behavioral responses in the resting-state MEG data. Experimental results showed that the FD value of actual MEG was increased statistically in comparison with the artifactual MEG. The DFA and the HM present a best performance for analyzing simulated data and resting-state MEG data, respectively. © Springer-Verlag Berlin Heidelberg 2013.

In interpersonal communication, body posture and nonverbal behavior serve as important channels for transmitting social signals and these often vary among cultures. Specific body postures and actions have not only functional, but also affective elements. For example, in Japan, handing an object to another with both hands is considered polite behavior whereas using only one hand is not. In this study, we have examined whether handing with both hands and handing with one hand would produce indications of differential brain activities in the receiver, and whether this activity would differ among people with different cultural backgrounds. Changes in oxy-Hb concentration were measured by 48-channel near infrared spectroscopy (NIRS) from 51 female participants (25 Japanese and 26 non-Japanese). The experimenter handed a bottle to participants using both or one hand. Results showed different amounts of change in oxy-Hb concentrations in the inferior frontal regions, depending on whether one hand or both hands were used. Moreover, the pattern of brain reactions in the inferior frontal regions differed between our Japanese and non-Japanese participants. A discriminant analysis of differences in oxy-Hb values suggested that the degree of oxy-Hb reaction in the right side of inferior frontal regions could predict to which group the participants belonged. These results suggest that different cultural and habitual backgrounds may lead to different NIRS activity while interpreting another's actions, and oxy-Hb IFG concentration may reflect differential interpretations of another's actions.

It is difficult to identify a target in the peripheral visual field when it is flanked by close distractors. In the present study, we investigated this "crowding" effect on the ability to discriminateion of the direction of a point-light biological motion. Three point-light walkers were presented horizontally in the periphery and the central figure was the target. When the inter-walker distance was small, discriminating the direction of the target became difficult. Moreover, the reported direction for the target was reflected in the pooling of the three directions. These results indicate that crowding occurs for biological motion perception. However, when the scrambled point-light walkers flanked the target as distractors, crowding was not seen. This result suggests that crowding in biological motion perception occurs at a high level of motion perception.

In this study, we examined whether luminance processing in the human visual system would exhibit any history effect (i.e., inter-trial modulation) in psychophysical and magnetoencephalographic experiments. A disk was presented against a black background at various luminance levels in a randomized order. During the MEG recording, participants were instructed to rate the brightness of the disk (magnitude estimation) and to report it aloud during inter-stimulus interval. The MEG results showed that the neuromagnetic activation around 200-220 ms after the stimulus onset in the left occipito-temporal regions at a given trial was weaker when the disk luminance in the immediately prior trial was higher. An inverse inter-trial effect was also observed in the psychophysical experiment. These findings suggest that the neuromagnetic activity reflects the inter-trial modulation of luminance processing that correlates with the subjective perception of brightness.

Studies have found that preferences for visual features such as colors and shapes reveal systematic tendencies; certain colors and shapes were more liked than others [1,8,9,11,13]. However, little has been known about the relationship between preferences for color and shape. Here, using an individual differences approach, we investigated whether there would be any correlations between preferences for color and shape. Sixty-nine Japanese university students rated how much they liked colors and shapes in separate sessions. The visual stimuli contained 40 colors taken from the Natural Color System, and 102 visual shapes ranging from simple 2D shapes (i.e., circle and triangle) and 2D projections of 3D objects (i.e., cone and pyramid). Results indicated that preferences for certain colors and shapes correlated with each other; the simple 2D shapes were tended to be preferred by the participants who preferred "warm" colors and the 3D shapes were tended to be preferred by the participants who preferred "cold" colors. Those results might be interpreted as manifestations of the shared semantic impressions (i.e., light-heavy) between colors and shapes.

In the present study, we examined recognition performance with back view of a person in an accidental recognition paradigm. Participants performed a dummy evaluation task of individually presented photographs of persons (either front view or back view of male or female individuals) without knowing that they would subsequently perform an accidental recognition test with front view. The recognition performance was generally low when the back view faces were shown during the evaluation session, compared with when the front view faces were shown. However, it was better than chance level except when male participants viewed female photographs. The results also supported the female advantage in person recognition (i.e., female participants were generally better) and partly the own gender bias even with the back view photographs (i.e., person recognition of persons in the same gander group was better). One possible explanation for the present findings would be that the recognition of persons with memory of back-views is based on the outlines and other contextual information (e.g., head-shape, hair-style, hair color) and the female participants might pay more attention to those contextual information, which might lead to the higher recognition performance. © 2013 IEEE.

Previous studies have reported retrospective influences of visual events that occur after target events. In the attentional attraction effect, a position cue presented after a target stimulus distorts the target's position towards that of the cue. The present study explored the temporal relationship between stimulus presentation and reaction time (RTRT) in this effect in two experiments. Participants performed a speeded localization task on two vertical lines, the positions of which were to be distorted by an additional attentional cue. No significant difference in RTRTs was found between the conditions with simultaneous and delayed cues. RTRT was modulated by the perceived (rather than physical) alignment of the lines. In Experiment 2, we manipulated the strength of attentional capture by modulating the color relevance of the cue to the target. Trials with cues producing stronger attentional capture (with cues of a different color from the targets) were found to induce apparently stronger distortion effects. This result favors the notion that the observed repulsion and attraction effects are driven by attentional mechanisms. Overall, the results imply that the attentional shift induced by the cue might occur rapidly and complete before the establishment of conscious location representation of the cue and the target without affecting overall response time.

An automatic artifact removal method of magnetoencephalogram (MEG) was presented in this paper. The method proposed is based on independent components analysis (ICA) and support vector machine (SVM). However, different from the previous studies, in this paper we consider two factors which would influence the performance. First, the imbalance factor of independent components (ICs) of MEG is handled by weighted SVM. Second, instead of simply setting a fixed weight to each class, a re-weighting scheme is used for the preservation of useful MEG ICs. Experimental results on manually marked MEG dataset showed that the method proposed could correctly distinguish the artifacts from the MEG ICs. Meanwhile, 99.72%+/- 0.67 of MEG ICs were preserved. The classification accuracy was 97.91%+/- 1.39. In addition, it was found that this method was not sensitive to individual differences. The cross validation (leave-one-subject-out) results showed an averaged accuracy of 97.41%+/- 2.14.

Attractiveness judgment based on visual appearance seems easy and almost automatic. However, it becomes difficult when we need to rely on glances of a person's back view (eg while passing on the street). How is attractiveness judgment from the back view consistent with that from full-front view? In experiment 1 participants rated the attractiveness of human heads photographed from behind and from the front. Attractiveness ratings between the back and front views were weakly but significantly correlated. However, on average, the back-view photographs were rated more attractive than the front-view photographs. The tendency was most conspicuous when the male participants viewed the photographs of women. In experiment 2 participants were explicitly asked to predict the facial attractiveness of each head's front view based on the back view. Again, the predicted attractiveness based on the back view was higher than the actual rating of the front-view photographs, and the difference reached significance when the male participants viewed the women photographs. These biases in attractiveness judgment would be related to attractiveness judgments in everyday situations where straight full-frontal encounters are rare.

Previous studies have explored the effects of attention on spatial representation. Specifically, in the attentional repulsion effect, a transient visual cue that captures attention has been shown to alter the perceived position of a target stimulus to the direction away from the cue. The effect is also susceptible to retrospective influence, that attention appears to attract the target when the cue appears afterwards. This study examined the necessity of visual awareness of the cue in these phenomena. We found that when the cues were rendered invisible by backward visual masks, both repulsion and attraction effects were weakened but still observed. The results suggest that the effects possibly depend on processes that are not necessarily associated with conscious visual awareness of the cues. We conjecture that attentional shift produced by the weak, invisible cues may play a role in spatial distortion
but other possible accounts including non-attentional ones are also discussed. © 2012 Elsevier Inc.

It is difficult to identify a target in the peripheral visual field when it is flanked by distractors. In the present study, we investigated this "crowding" effect for biological motion stimuli. Three walking biological motion stimuli were presented horizontally in the periphery with various distances between them, and observers reported the walking direction of the central figure. When the inter-walker distance was small, discriminating the direction became difficult. Moreover, the reported direction for the central target was not simply noisier, but reflected a degree of pooling of the three directions from the target and two flankers. However, when the two flanking distractors were scrambled walking biological motion stimuli, crowding was not seen. This result suggests that the crowding of biological motion stimuli occurs at a high-level of motion perception.

When two images, one depicting colored disks and the other depicting colored windmill patterns, are displayed in succession, the color of the windmills is perceptually replaced by black. The illusion is striking. Experiments confirmed (1) that the luminance contrast between the target patterns and the background must be large and (2) that the disks and windmills must be static on the retina and in register. The illusion is weakened when the windmills and disks have different colors.

The estimation of numerosity of a large number of objects in a static visual display is possible even at short durations. Such coarse approximations of numerosity are distinct from subitizing, in which the number of objects can be reported with high precision when a small number of objects are presented simultaneously. The present study examined numerosity estimation of visual objects in dynamic displays and the effect of object similarity on numerosity estimation. In the basic paradigm (Experiment 1), two streams of dots were presented and observers were asked to indicate which of the two streams contained more dots. Streams consisting of dots that were identical in color were judged as containing fewer dots than streams where the dots were different colors. This underestimation effect for identical visual items disappeared when the presentation rate was slower (Experiment 1) or the visual display was static (Experiment 2). In Experiments 3 and 4, in addition to the numerosity judgment task, observers performed an attention-demanding task at fixation. Task difficulty influenced observers' precision in the numerosity judgment task, but the underestimation effect remained evident irrespective of task difficulty. These results suggest that identical or similar visual objects presented in succession might induce substitution among themselves, leading to an illusion that there are few items overall and that exploiting attentional resources does not eliminate the underestimation effect.

Visual images that are not faces are sometimes perceived as faces (the pareidolia phenomenon). While the pareidolia phenomenon provides people with a strong impression that a face is present, it is unclear how deeply pareidolia faces are processed as faces. In the present study, we examined whether a shift in spatial attention would be produced by gaze cueing of face-like objects. A robust cueing effect was observed when the face-like objects were perceived as faces. The magnitude of the cueing effect was comparable between the face-like objects and a cartoon face. However, the cueing effect was eliminated when the observer did not perceive the objects as faces. These results demonstrated that pareidolia faces do more than give the impression of the presence of faces; indeed, they trigger an additional face-specific attentional process.

Shifts of attention can cause mislocalisation of visual objects. A brief cue that attracts attention can cause a shift in the perceived location of a subsequently presented visual object specifically, moving it away from the focus of attention (attentional repulsion). In the present study we investigated whether depth would influence the magnitude of attentional repulsion by presenting peripheral visual cues in different depth planes from the target or fixation. In experiment 1 the results showed that the magnitude of the attentional repulsion was larger when the cue was presented at the depth plane farther away from the target and fixation. In experiment 2 we presented the fixation point in the same depth plane as the nearest cues and found larger repulsion effects when the cues were presented in depth planes farther away from the fixation. In experiment 3 no depth modulation was observed when the fixation was presented in the same depth plane with the farthest cues. Taken together, when the cues were presented in the depth plane farther away from the fixation, the magnitude of the attentional repulsion effect increased. It is speculated that the residual coarser spatial representation in the space farther from the fixation plane or the enhanced attentional process for the space closer than the fixation may be responsible for the larger attentional repulsion effect.

Prediction and evaluation errors of self-performance (overestimation and underestimation) occasionally bring serious consequences. This study examined possible causes for overestimation and underestimation using a newly devised experimental paradigm. The experiment comprised two sessions: in the first session, participants learned rules for button presses in response to particular combinations of digits, and in the second session, they performed a similar task with the same rules but in response to English letters and they were randomly assigned to one of three tasks with different button configurations: Sequential, Reversed, and Partially reversed. The participants predicted and evaluated their performance before and after each session, respectively. It was found that participants tended to overestimate both predictions and evaluations of performance on the Partially reversed task. These results suggest that differential changes in stimulus-response association lead to differentially biased estimations. In particular, people might underestimate the switching costs from ordinal to non-ordinal representation.

Time perception is involved in various cognitive functions. This study investigated the characteristics of short-term memory for event duration by examining how the length of the retention period affects inter- and intramodal duration judgment. On each trial, a sample stimulus was followed by a comparison stimulus, after a variable delay period (0.5-5 s). The sample and comparison stimuli were presented in the visual or auditory modality. The participants determined whether the comparison stimulus was longer or shorter than the sample stimulus. The distortion pattern of subjective duration during the delay period depended on the sensory modality of the comparison stimulus but was not affected by that of the sample stimulus. When the comparison stimulus was visually presented, the retained duration of the sample stimulus was shortened as the delay period increased. Contrarily, when the comparison stimulus was presented in the auditory modality, the delay period had little to no effect on the retained duration. Furthermore, whenever the participants did not know the sensory modality of the comparison stimulus beforehand, the effect of the delay period disappeared. These results suggest that the memory process for event duration is specific to sensory modality and that its performance is determined depending on the sensory modality in which the retained duration will be used subsequently.

Motor skill memory is first encoded online in a fragile form during practice and then converted into a stable form by offline consolidation, which is the behavioral stage critical for successful learning. Praise, a social reward, is thought to boost motor skill learning by increasing motivation, which leads to increased practice. However, the effect of praise on consolidation is unknown. Here, we tested the hypothesis that praise following motor training directly facilitates skill consolidation. Forty-eight healthy participants were trained on a sequential finger-tapping task. Immediately after training, participants were divided into three groups according to whether they received praise for their own training performance, praise for another participant's performance, or no praise. Participants who received praise for their own performance showed a significantly higher rate of offline improvement relative to other participants when performing a surprise recall test of the learned sequence. On the other hand, the average performance of the novel sequence and randomly-ordered tapping did not differ between the three experimental groups. These results are the first to indicate that praise-related improvements in motor skill memory are not due to a feedback-incentive mechanism, but instead involve direct effects on the offline consolidation process.

Many studies suggest that the color category influences visual perception. It is also well known that oculomotor control and visual attention are closely linked. In order to clarify temporal characteristics of color categorization, we investigated eye movements during color visual search. Eight color disks were presented briefly for 20-320 ms, and the subject was instructed to gaze at a target shown prior to the trial. We found that the color category of the target modulated eye movements significantly when the stimulus was displayed for more than 40 ms and the categorization could be completed within 80 ms. With the 20 ms presentation, the search performance was at a chance level, however, the first saccadic latency suggested that the color category had an effect on visual attention. These results suggest that color categorization affects the guidance of visual attention rapidly and implicitly.

Time duration is perceived to be longer when accompanied by dynamic sensory stimulation than when accompanied by static stimulation. This distortion of time perception is thought to be due to the acceleration of an internal pacemaker that has been assumed to be the main component of temporal judgments. In order to investigate whether the function of the internal pacemaker is modality dependent or independent, we examined the correlation of visual flicker and auditory flutter effects on a temporal production task. While seeing a 10-Hz visual flicker or hearing a 10-Hz auditory flutter, participants estimated a duration of 2500 ms as accurately as possible by pressing a button. The results showed a significant within-individual correlation between the time distortion due to visual flicker and that due to auditory flutter. Additionally, we found that time distortion due to auditory flutter tended to be larger in female participants than in male participants. These results suggest that the mechanisms underlying subjective time dilation are similar between vision and audition within individuals, but that they vary across individuals.

Recent developments in measurement techniques have enabled us to observe the time series of many components simultaneously. Thus, it is important to understand not only the dynamics of individual time series but also their interactions. Although there are many methods for analysing the interaction between two or more time series, there are very few methods that describe global changes of the interactions over time. Here, we propose an approach to visualise time evolution for the global changes of the interactions in complex systems. This approach consists of two steps. In the first step, we construct a meta-time series of networks. In the second step, we analyse and visualise this meta-time series by using distance and recurrence plots. Our two-step approach involving intermediate network representations elucidates the half-a-day periodicity of foreign exchange markets and a singular functional network in the brain related to perceptual alternations.

To locate relevant information within an vast array of potentially irrelevant information, a graphical user interface supported by visual navigation search cues may be useful. Because few studies have reported effects of visual cues in complicated workplace conditions, this study examined effects of valid/invalid cues on performance in a search task that simulated central monitoring task. Reaction times (RTs) to targets were measured for valid/invalid cues relative to no-cue conditions. Results indicated that cost (increment of RT by the invalid cue) is less than benefit (decrement of RT by the valid cue). Subsequently, to examine effects of cues in a perception/cognition phase, rates of correct answers were measured by eliminating an action phase of the search task. Results reveal the benefit (higher rate of correct answers in the valid cue condition than in the no-cue condition) was greater than the cost (lower rate of correct answers in the invalid cue condition than in the no-cue condition). Additionally, eye movement data indicated that onset times of eye fixation to a cued button were concentrated within 200-300ms regardless of cue condition. Together, results suggest that in a complicated search situation, such as a central control system, the costs for relying on invalid cues can be expressed as 1/d, with d as the number of candidates of search. This implies that as d increases the usefulness of a predictive (valid) cue increases. Copyright © 2012 ACM.

Recently, an independent component analysis (ICA) has been proven to be an effective method for removing artifacts and noise in multi-channel physiological measures. ICA can extract independent component (IC) which was directly regarded as artifacts. In this paper, we propose an automatic method for classifying physiological artifacts from magnetoencephalogram (MEG) data. The artifactual ICs were classified based on support vector machine (SVM) algorithm. The following parameters: kurtosis (K), probability density (PD), central moment of frequency (CMoF), spectral entropy (SpecEn), and fractal dimension (FD) were used as input vector of SVM. The proposed method showed the average classification rates of 99.18%, 92.33%, and 98.15% for cardiac (EKG), ocular (EOG), and high-amplitude changes (HAM), respectively.

Resting-state study is a useful tool to investigate the brain activity related to cognitive abilities in children because it may be difficult for children to perform some experimental tasks. In the present study, we report a preliminary examination to associate the resting-state neuromagnetic signals from magnetoencephalogram (MEG) with cognitive abilities in children. We applied a non-linear time-series analysis for 90-s resting-state neuromagnetic signals and estimated interdependency of two channels of MEG signals. Then we examined the relation between the magnitudes of interdependency and the cognitive abilities and ages. Although we found some indications of age differences in the lateralization of interdependency, the results highlighted several limiting factors in measuring cognitive abilities and resting-state neuromegnetic signals in children and suggested that further elaboration of devices, procedures, and analysis would be warranted.

Radial lines of Ehrenstein patterns induce illusory scintillating lustre in gray disks inserted into the central gaps (scintillating-lustre effect). We report a novel variant of this illusion by replacing the radial lines with white and black radial fins. Both white and gray disks inserted into the central gaps were perceived as scintillating, if the ratio of the black/white fin width were balanced (ie, close to 1.0). Thus, the grayness of the central disk is not a prerequisite for the scintillation. However, the scintillation was drastically reduced when the ratio was imbalanced. Furthermore, the optimal ratio depended on the color of the center disks.

Time perception of visual events depends on the visual attributes of the scene. Previous studies reported that motion of object can induce an illusion of lengthened time. In the present study, we asked the question whether such time dilation effect depends on the actual physical motion of the object (spatiotopic coordinate), or its relative motion with respect to the retina (retinotopic coordinate). Observers were presented with a moving stimulus and a static reference stimulus in separate intervals, and judged which interval they perceived as having a longer duration, under conditions with eye fixation (Experiment 1) and with eye movement at same velocity as the moving stimulus (Experiment 2). The data indicated that the perceived duration was longer under object motion, and depended on the actual movement of the object rather than relative retinal motion. These results are in support with the notion that the brain possesses a spatiotopic representation regarding the real world positions of objects in which the perception of time is associated with.

Abrupt onsets of visual cues capture an observer's attention, even when the cues do not reach the observer's visual awareness. In the present study, we investigated the effects of subthreshold cues on the performance of a useful field of view task. Participants localized a target stimulus presented in the peripheral visual field while identifying a character presented at the fovea. Before the presentation of central and peripheral targets, a suprathreshold or subthreshold cue indicating a likely location of the peripheral target was presented. We found that the suprathreshold cue led to both a benefit in the valid trials and cost in the invalid trials, while the subthreshold cue produced only a benefit in the valid trials without a cost in the invalid trials. Similar patterns of results were also observed when the cue preceded the targets by 10-200 ms, although a small cost was observed for the 12 deg eccentricity at the stimulus onset asynchronies of 50 ms and 100 ms in the subthreshold condition. These results indicate that attentional capture occurs without awareness of the cue and suggest that the effect of the cue on the spatial shift of attention would be different between the suprathreshold and subthreshold conditions.

Subjective impressions of face images (eg personality trait judgments) are consistent across exposure durations and viewpoints. In this study, we investigated whether subjective likeability of common non-face objects would also be consistent. Participants rated the likeability of 32 common objects (eg chair, car, and kettle). Although the rated likeability scores were generally higher for objects shown in three-quarter views than for the same objects shown in full-frontal views, object-wise correlations across the views were significant (experiment 1). The likeability ratings based on brief exposure duration (eg 100 ms) also significantly correlated with those based on unlimited exposure duration (experiment 2). Even when the duration was brief, the consistency across the views was replicated. The findings confirmed that the subjective likeability of common objects is consistent and the process underlying it is efficient, similar to those of faces. However, the mean rated likeability was higher for longer exposure durations, suggesting a negative bias for briefly observed objects. Since this bias is contrary to previously reported findings for faces, the mechanisms for determining subjective likeability of common objects may be partially different from those of faces.

To estimate the minimal time required to process visual information (ie "effective acquisition time") during a visual search task, we used a gaze-contingent visual masking method. In the experiment, an opaque mask that restricted the central vision was presented at a current gaze position. We manipulated a temporal delay from a gaze shift to mask movement. Participants were asked to search for a target letter (T) among distractor letters (L)s as quickly as possible under various delays. The results showed that the reaction times and search rate decreased when the delay was increased. When the delay was longer than 50 ms, the reaction times and search rate reached a plateau. These results indicate that the effective acquisition time during the visual search task used in the study is equal to or less than 50 ms. The present study indicates that the gaze-contingent visual masking method used is useful for revealing the effective acquisition time.

The abacus, a traditional physical calculation device, is still widely used in Asian countries. Previous behavioral work has shown that skilled abacus users perform rapid and precise mental arithmetic by manipulating a mental representation of an abacus, which is based on visual imagery. However, its neurophysiological basis remains unclear. Here, we report the case of a patient who was a good abacus user, but transiently lost her "mental abacus" and superior arithmetic performance after a stroke owing to a right hemispheric lesion including the dorsal premotor cortex (PMd) and inferior parietal lobule (IPL). Functional magnetic resonance imaging experiments were conducted 6 and 13 months after her stroke. In the mental calculation task, her brain activity was shifted from the language-related areas, including Broca's area and the left dorsolateral prefrontal and IPLs, to the visuospatial-related brain areas including the left superior parietal lobule (SPL), according to the recovery of her arithmetic abilities. In the digit memory task, activities in the bilateral SPL, and right visual association cortex were also observed after recovery. The shift of brain activities was consistent with her subjective report that she was able to shift the calculation strategy from linguistic to visuospatial as her mental abacus became stable again. In a behavioral experiment using an interference paradigm, a visual presentation of an abacus picture, but not a human face picture, interfered with the performance of her digit memory, confirming her use of the mental abacus after recovery. This is the first case report on the impairment of the mental abacus by a brain lesion and on recovery-related brain activity. We named this rare case "abacus-based acalculia." Together with previous neuroimaging studies, the present result suggests an important role for the PMd and parietal cortex in the superior arithmetic ability of abacus users.

We proposed a new cognitive visual model of movie recognition based on our previous findings of psychophysical phenomena. Our cognitive model suggested two important functions of movie recognition process. First, a continuous movie sequence was divided and perceived as serial event segments of short scenes. The movie would be coded for each of the segments and structuralized as a contextual association of each segments. Second, the knowledge structure of the context of previously viewed movies was used to predict the ongoing movie context and the online segmentation. We compared our cognitive model with a previously proposed theoretical model of movie processing. The results of our experiments supported our hypothesis: an adaptive learning mechanism of online movie segmentation would be effective for an intelligent knowledge-based structure of a future movie analysis system.

Shifts of visual attention cause systematic distortions of the perceived locations of visual objects around the focus of attention. In the attention repulsion effect, the perceived location of a visual target is shifted away from an attention-attracting cue when the cue is presented before the target. Recently it has been found that, if the visual cue is presented after the target, the perceived location of the target shifts toward the location of the following cue. One unanswered question is whether a single mechanism underlies both attentional repulsion and attraction effects. We presented participants with two disks at diagonal locations as visual cues and two vertical lines as targets. Participants were asked to perform a forced-choice task to judge targets' positions. The present study examined whether the magnitude of the repulsion effect and the attraction effect would differ (Experiment 1), whether the two effects would interact (Experiment 2), and whether the location or the dynamic shift of attentional focus would determine the distortions effects (Experiment 3). The results showed that the effect size of the attraction effect was slightly larger than the repulsion effect and the preceding and following cues have independent influences on the perceived positions. The repulsion effect was caused by the location of attnetion and the attraction effect was due to the dynamic shift of attentional focus, suggesting that the underlying mechanisms for the retrospective attraction effect might be different from those for the repulsion effect.

We investigated whether implicit learning in a visual search task would influence preferences for visual stimuli. Participants performed a contextual cueing task in which they searched for visual targets, the locations of which were either predicted or not predicted by the positioning of distractors. The speed with which participants located the targets increased across trials more rapidly for predictive displays than for non-predictive displays, consistent with contextual cueing. Participants were subsequently asked to rate the "goodness" of visual displays. The rating results showed that they preferred predictive displays to both non-predictive and novel displays. The participants did not recognize predictive displays any more frequently than they did non-predictive or novel displays. These results suggest that contextual cueing occurred implicitly and that the implicit learning of visual layouts promotes a preference for visual layouts that are predictive of target location.

Background. Transcranial direct current stimulation (tDCS) of the motor cortex can enhance the performance of a paretic upper extremity after stroke. Reported effects on lower limb (LL) function are sparse. Objective. The authors examined whether tDCS can increase the force production of the paretic quadriceps. Methods. In this double-blind, crossover, sham-controlled experimental design, 8 participants with chronic subcortical stroke performed knee extension using their hemiparetic leg before, during, and after anodal or sham tDCS of the LL motor cortex representation in the affected hemisphere. Affected hand-grip force was also recorded. Results. The maximal knee-extension force increased by 21 N (13.2%, P < .01) during anodal tDCS compared with baseline and sham stimulation. The increase persisted less than 30 minutes. Maximal hand-grip force did not change. Conclusions. Anodal tDCS transiently enhanced knee extensor strength. The modest increase was specific to the LL. Thus, tDCS might augment the rehabilitation of stroke patients when combined with lower extremity strengthening or functional training.

Knowing where people look when viewing faces provides an objective measure into the part of information entering the visual system as well as into the cognitive strategy involved in facial perception. In the present study, we recorded the eye movements of 20 congenitally deaf (10 male and 10 female) and 23 (11 male and 12 female) normal-hearing Japanese participants while they evaluated the emotional valence of static face stimuli. While no difference was found in the evaluation scores, the eye movements during facial observations differed among participant groups. The deaf group looked at the eyes more frequently and for longer duration than the nose whereas the hearing group focused on the nose (or the central region of face) more than the eyes. These results suggest that the strategy employed to extract visual information when viewing static faces may differ between deaf and hearing people.

In psychophysical scaling, a subjective rating in the current trial is tend to be biased by preceding trials (sequential effect). Here, we investigated the factor determining the sequential effect: physical stimulus, evaluation process, or response in the preceding trials. Participants observed disks with different luminance values and rated the perceived brightness of the disk on a 9-point scale. When participants were required to evaluate and response to the 1-back trials, the current rating was assimilated toward 1-back trials. On the other hand, when participants were not required to evaluate the 1-back stimulus, the current rating was not affected by 1-back trials, independent of whether the response to the 1-back stimulus was required or not. These results suggest that the sequential effect was due to evaluation process but not to stimulus or response in the preceding trials. © 2011 IEEE.

This study investigated whether normal adults were able to discriminate agency from the perceived traces or trajectories of past actions such as handwritings. Subjects wrote two types of component parts of Chinese characters, either mastered and unmastered, and were later shown various handwritten strokes and judged whether each of them had been written by themselves or by someone else. We found that people tended to answer that the handwritings had been written by others when they saw unmastered types of strokes, while they tended to answer that the handwritings had been written by themselves when they saw mastered types of strokes. This finding suggests a tight interplay among perception, self-consciousness, and memorized action in the motor system and adds to our knowledge about a higher order representation level in the agency recognition. Possible cognitive neuroscientific implications and engineering applications of the finding are also discussed. © 2011 IEEE.

A purpose of this study is to clarify the relationship between the usability of information technology devices in business use and the cognitive characteristics of aged people. A central control room is a workplace often staffed with aging personnel. In order to investigate what kind of a decline in cognitive function of older adults affects their operational abilities, we tested participants who were then classified into three groups according to the type of decline in their cognitive characteristics: a decline in working memory (WM), a decline in visual attention (AT), or a decline in task-switching (TS). In addition, people with completely normal cognitive function were recruited as a control group. A simulator of a central monitoring device was prepared to examine performance of an inspection operation. Reaction time data showed a significant difference between the controls and the WM group (p&lt;.05). For the error ratio, a significant difference was seen between controls and the TS group (p&lt;.05). Performance on the inspection task was negatively affected by the decline in working memory and in task switching. Based on these results, we discuss a design that can compensate for such cognitive aging effects.

We investigated how interpersonal haptic telecommunication would affect the impression of an experience shared with another person. We conducted a psychological experiment wherein two people watched a comedy movie at the same time but in distant locations. They were asked to press a button when they found the movie hilarious, and this produced a vibratory haptic stimulation to the other person. Thus, the two people were able to interact with each other and know the other person's reaction through haptic telecommunication. In one group, the haptic stimulation was interrupted for 90 s during the movie presentation. We found that the number of button presses decreased during the interruption period, suggesting that the feeling of hilarity could be modulated by communication with the other person. A post-experiment questionnaire survey confirmed that the uninterrupted group tended to attribute the hilarious feeling they experienced to sharing with the other person, and also expressed stronger empathy towards the other person. These results suggest that haptic telecommunication may alter the quality of shared experience and increase the intimacy felt towards the other person. © 2011 IEEE.

Prediction and evaluation errors of self-performance (overestimation and underestimation) sometimes bring serious consequences. The present study examined possible causes for over- and under-estimations by using a newly devised task-transfer paradigm. The experiment consisted of two sessions. In the first learning session, participants learned rules for button presses in response to particular combinations of digits. In the second test session, they performed a similar task with the same rules but in response to English alphabets. In addition, the participants were randomly assigned to one of three tasks with different button configurations: Unchanged, Reversed, and Flipped. They predicted/evaluated their performance before/after the sessions. The task performance tended to be underestimated for the Reversed task and was overestimated in the Flipped task. These results suggest that differential changes in stimulus-response association lead to underestimation or overestimation. © 2011 IEEE.

We investigated how tactile stimuli induced feelings of animacy and pleasantness in human observers. First, we developed a new tactile display that enabled limp yet powerful tactile stimulations with a wide range of frequencies. Second, we examined the induced sensation by tactile stimulation as a function of stimulus frequency and body part. We found that the feeling of animacy was dependent upon stimulus frequency. The 12 Hz stimulation induced the strongest feeling of animacy. The frequency dependence was qualitatively similar but quantitatively different between finger and wrist stimulation. In addition, the modest feeling of animacy was associated with the strong feeling of pleasantness in finger stimulation. These results suggest that tactile stimulation can induce feelings of animacy in a frequency-dependent manner and that the frequency dependence and induced emotion of tactile stimulation may differ among different body parts.

The present study examined the effect of extrinsic motivation on temporal interval production. Observers were asked to produce the duration of 2.5 sec as accurately as possible, and gained or lost a certain amount of score after each trial. The amount of provided scores varied with the color of target: red or green circle was assigned to high or low scores. We found that the higher amount of expected gain and loss decreased the absolute error of temporal production. However, no effect of motivation was found on the constant error and variable error. These results suggest that extrinsic motivation improved the precision of temporal production. We propose that the striatal dopamine system may mediate motivational influences on time perception. © 2011 IEEE.

The visual system dynamically modulates attention to identify a target embedded in a rapid sequence of nontargets. Typically, the accuracy of target identification increases as the number of preceding items increases and is maintained at this increased level: Known as the attentional awakening phenomenon. In this study, we investigated the temporal characteristics of the visual system that contribute to maintaining attentional state throughout a trial. In Experiment 1, we initially demonstrated that the enhanced state of attention was reset after a gap of 500-1000 ms that was inserted in the sequence. In Experiment 2, we found that the attentional state was maintained when the temporally separated sequences were encapsulated by a continuous sequence of random dots. In the following experiments, we systematically manipulated the spatiotemporal configurations of random dots (or used a different object) and found that the attentional state was maintained as long as the object continuity was maintained.

In visual competition, the perception of ambiguous visual patterns changes spontaneously. Although the process causing this perceptual alternation remains unclear, recent evidence suggests various types of non-visual influences in resolving visual ambiguity. In the present study, we investigated cross-modal modulation of a transient stimulus on visual perceptual stability (i.e., alternation frequency). Participants observed an ambiguous visual figure and reported their perceptual alternations. Concurrently, we presented visual and auditory transient events. The results revealed that the auditory as well as visual transient events destabilize the current perception (i.e., they increase alternation frequency) around 0.5-1.5 s after the event. In addition, the magnitudes of auditory and visual effects were comparable and positively correlated within participants. These results suggest that the visual perceptual stability can be under the influence of processes that are shared by different senses. (C) Koninklijke Brill NV, Leiden, 2011

We can easily recognize human movements from very limited visual information (biological motion perception). The present study investigated how upper and lower body areas contribute to direction discrimination of a point-light (PL) walker. Observers judged the direction that the PL walker was facing. The walker performed either normal walking or hakobi, a walking style used in traditional Japanese performing arts, in which the amount of the local motion of extremities is much smaller than that in normal walking. Either the upper, lower, or full body of the PL walker was presented. Discrimination performance was found to be better for the lower body than for the upper body. We also found that discrimination performance for the lower body was affected by walking style and/or the amount of local motion signals. Additional eye movement analyses indicated that the observers initially inspected the region corresponding to the upper body, and then the gaze shifted toward the lower body. This held true even when the upper body was absent. We conjectured that the upper body subserved to localize the PL walker and the lower body to discriminate walking direction. We concluded that the upper and lower bodies play different roles in direction discrimination of a PL walker.

We used magnetoencephalography (MEG) to investigate the timing and location of cortical activity related to perceived brightness. Participants passively observed 1 of 5 disks of different luminance (1, 3.2, 10, 32, and 100 cd/m(2)) during MEG recording, and rated the perceived brightness of the disk before and after the MEG recording. The perceived brightness showed an almost perfect log-linear dependence on luminance intensity. The MEG results showed that the stimulus presentation evoked neuromagnetic responses in the occipital region approximately 150 ms after stimulus onset. The average magnitude of the response was positively correlated with the subjective ratings of perceived brightness as well as the log-scaled stimulus luminance. These findings suggest that the neuromagnetic responses in the occipital cortex reflect subjective brightness perception and that the visual cortex completes the brightness assignment as early as 150 ms after stimulus onset. The possible clinical application of these results is discussed.

Oscillations in the higher frequency range are closely related to regional brain hemodynamic changes. Here we investigated this neurovascular coupling in humans in response to electrical stimulation of the right median nerve. In a single-trial study, we simultaneously recorded hemodynamic fluctuations in the somatosensory cortex by near infrared spectroscopy and brain neuronal oscillations by whole-head magnetoencephalography (MEG). The results from six volunteers showed that neural fluctuations at beta or gamma-band power were correlated with hemodynamic fluctuation during stimulus conditions. These correlations were prominent with a time delay of 5-7 s. This study provides new direct evidence that hemodynamic onset lags specific neural oscillations in the order of seconds in human awake conditions using noninvasive methods. NeuroReport 21:1106-1110 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Exogenous attention enhances the perception of attended items in both a space-based and an object-based manner. Exogenous attention also improves recognition memory for attended items in the space-based mode. However, it has not been examined whether object-based exogenous attention enhances recognition memory. To address this issue, we examined whether a sudden visual change in a task-irrelevant stimulus (an exogenous cue) would affect participants' recognition memory for items that were serially presented around a cued time. The results showed that recognition accuracy for an item was strongly enhanced when the visual cue occurred at the same location and time as the item (Experiments 1 and 2). The memory enhancement effect occurred when the exogenous visual cue and an item belonged to the same object (Experiments 3 and 4) and even when the cue was counterpredictive of the timing of an item to be asked about (Experiment 5). The present study suggests that an exogenous temporal cue automatically enhances the recognition accuracy for an item that is presented at close temporal proximity to the cue and that recognition memory enhancement occurs in an object-based manner.

Continuous temporal changes in environmental situations in everyday life can be segmented, in the perception process, into events. In this study, we examine whether contextual segmentation affects visual perception. Fodor and Bever (1965) discovered the temporal synchronization effect on speech perception of contextual segments in spoken language. We converted Fodor&apos;s auditory paradigm into a visual task by converting the auditory streams into visual streams, and the brief sounds into brief visual flashes. The detection of a similar temporal synchronization effect would strongly support the perception of a visual stream as the context of the visual event. We conducted two experiments using movies with natural scenes and edited scene segments to examine whether an explicit movie segment had a temporal synchronization effect on flash timing and whether changes in the action context had a similar effect. The results showed that the visual stream could be perceived within contextual segmentation.

Developmental disorders such as attention-deficit/hyperactivity disorder (ADHD) and Asperger syndrome (AS) are often associated with learning disabilities. This study investigated the explicit learning of visuomotor sequences in 17 ADHD children (mean age 12.1), 21 AS children (mean age 12.7), and 15 typically developing children (mean age: 12.3). The participants were required to explore a hidden sequence of button presses by trial and error and elaborate the learned sequence (2 x 10 task: Hikosaka et al. 1996). The results indicated that although ADHD and AS children had a tendency of repeating the same errors and took longer to complete a sequence, both showed a degree and pattern of improvement in accuracy and speed similar to that of typically developing children. These results suggest that the explicit learning of visuomotor sequence in ADHD and AS patients is largely unimpaired.

The present study examined neural correlates of subjective simultaneity by using magnetoencephalography. Observers were asked to judge whether the visual and auditory stimuli occurred simultaneously. The subjective judgment for 90-ms-asynchronous stimuli showed trial-by-trial variation, and we successfully classified subjective simultaneity using neuromagnetic signals. We submitted raw MEG signals, a wavelet transform, and nonlinear dynamics to a naive Bayes classifier. In the case of raw signals and nonlinear dynamics, the classifier trained with the VA (where the visual stimulus was given first) or AV (where the visual stimulus was given second) data could predict the subjective simultaneity of the other VA (or AV) data at a rate better than chance. The classification rate using nonlinear dynamics was comparable to that using raw signals, despite the fact that the dimension was considerably low (101 vs. 88,000 dimensions). In the case of the wavelet transform, the classifier trained with the VA data was able to decode the AV data, and vice versa. These results suggest that (1) we can decode subjective simultaneity using MEG signals. (2) nonlinear dynamics may encode simultaneity specific to the order of the audiovisual inputs, (3) the time-frequency characteristics of neural activity may predict subjective simultaneity independently of the physical order of the audiovisual inputs, and (4) the neural activity (time-frequency characteristics) reflecting subjective simultaneity may share a common mechanism among different sensory modalities.

Repetition of the same spatial configurations of a search display implicitly facilitates performance of a visual-search task when the target location in the display is fixed. The improvement of performance is referred to as contextual cueing. We examined whether the association process between target location and surrounding configuration of distractors occurs during active search or at the instant the target is found. To dissociate these two processes, we changed the surrounding configuration of the distractors at the instant of target detection so that the layout where the participants had searched for the target and the layout presented at the instant of target detection differed. The results demonstrated that both processes are responsible for the contextual-cueing effect, but they differ in the accuracies of attentional guidance and their time courses, suggesting that two different types of attentional-guidance processes may be involved in contextual cueing.

Visual competition refers to the spontaneous change of the subjective perception of ambiguous visual patterns. We investigated how implicit and explicit auditory inputs affect the temporal characteristics of perceptual alternation and the interpretation bias in ambiguous visual patterns. Participants traced the perceived direction of apparent visual motion, while two task-irrelevant auditory tones were alternately presented. In the pre- and post-learning sessions, ambiguous apparent motion (seen as moving vertically or horizontally) was presented. In the learning session, disambiguated vertical and horizontal apparent motions were alternately presented and switched in synchronization with the changes in auditory tones. The results showed that the temporal intervals of perceptual alternation from the auditory switches were reduced after the participants experienced the synchronized audiovisual switches, even when the auditory switches were not consciously detectable. The magnitude of the effect was comparable for the implicit and explicit auditory switches. Neither explicit nor implicit auditory tones biased the interpretation of the ambiguous visual motion. These results suggest that auditory inputs implicitly affect the temporal characteristics of perceptual alternation after participants experience synchronized audiovisual events.

Visual patterns consisting of a red-and-blue region with a blurry edge yield illusory motion. Eye movements over a static pattern induced illusory motion of the edge in the direction opposite to the eye movement. The illusion also takes place for patterns in motion without eye movement. The illusion suggests the effect of colour combination on the spatial perception of a blurry edge.

Pointing with the index finger is a universal behavior. However, the functional significance of indexical pointing has not been examined empirically. We examined the efficacy of various pointing gestures in evoking viewer&apos;s attentional shifts. After viewing the gesture cue, observers quickly reported the location of a visual target. With a short cue-target delay, reaction times were generally shorter for the target at the location where gesture cues pointed, but not with a long cue-target delay. Moreover, the indexical pointing gesture produced a significantly larger cueing effect than the other gestures. Our control experiments indicated that the index-finger advantage is tightly linked to the proper morphological shape (i.e. length and position of the index finger) of the indexical pointing and is not explained by the directional discriminability of the gesture. The visual system seems to use mechanisms that are partially independent of the directional discrimination of gestures, in order to quickly modulate the viewer&apos;s attention.

Background: Photosensitive epilepsy is a type of reflexive epilepsy triggered by various visual stimuli including colourful ones. Despite the ubiquitous presence of colorful displays, brain responses against different colour combinations are not properly studied.
Methodology/Principal Findings: Here, we studied the photosensitivity of the human brain against three types of chromatic flickering stimuli by recording neuromagnetic brain responses (magnetoencephalogram, MEG) from nine adult controls, an unmedicated patient, a medicated patient, and two controls age-matched with patients. Dynamical complexities of MEG signals were investigated by a family of wavelet entropies. Wavelet entropy is a newly proposed measure to characterize large scale brain responses, which quantifies the degree of order/disorder associated with a multifrequency signal response. In particular, we found that as compared to the unmedicated patient, controls showed significantly larger wavelet entropy values. We also found that Renyi entropy is the most powerful feature for the participant classification. Finally, we also demonstrated the effect of combinational chromatic sensitivity on the underlying order/disorder in MEG signals.
Conclusions/Significance: Our results suggest that when perturbed by potentially epileptic-triggering stimulus, healthy human brain manages to maintain a non-deterministic, possibly nonlinear state, with high degree of disorder, but an epileptic brain represents a highly ordered state which making it prone to hyper-excitation. Further, certain colour combination was found to be more threatening than other combinations.

Transcranial direct current stimulation (tDCS) is a procedure to polarize human brain. It has been reported that tDCS over the hand motor cortex transiently improves the performance of hand motor tasks. Here, we investigated whether tDCS could also improve leg motor functions. Ten healthy subjects performed pinch force (PF) and reaction time (RT) tasks using the left leg before, during and after anodal, cathodal or sham tDCS over the leg motor cortex. The anodal tDCS transiently enhanced the maximal leg PF but not RT during its application. Neither cathodal nor sham stimulation changed the performance. None of the interventions affected hand PF or RT, showing the spatial specificity of the effect of tDCS. These results indicate that motor performance of not only the hands but also the legs can be enhanced by anodal tDCS. tDCS may be applicable to the neuro-rehabilitation of patients with leg motor disability.

In this study, we examined whether visual context can be learned through a dynamic display and whether it can facilitate sustained attentional tracking by combining a multiple object tracking (MOT) task and a contextual cueing procedure. The trajectories of the targets and distractors in the MOT task were made invariant by repeatedly presenting them. The results revealed that when the targets were repeatedly displayed, tracking performance implicitly improved, and this effect was enhanced when the unattended distractors in the displays were also repeated. However, the repetition of the distractors alone did not produce any effect. Interestingly, when the targets and distractors were switched in a display in which the distractors had been previously repeated, the tracking performance was impaired as compared with that in the case of nonrepeated displays. We concluded that the contextual information in a dynamic display facilitates attentional tracking and that different types of contextual modulations occurred in MOT processes, such as facilitation for attended targets and inhibition for ignored distractors.

Presenting a target-like distractor in an RSVP task deteriorates the detection of a trailing target, because the visual system has difficulties in rejecting the erroneously accepted distractor. We investigated whether the rejection process is influenced by observers&apos; knowledge regarding possible distractors. Observers identified a letter (target) embedded in a stream of line patterns, rejecting a preceding distractor (digit). We informed the observers about either the category of distractors ("digit") or the identity of the distractor (e.g., "5"). The distractors with certain distractor-target lags increased identification errors, indicating that the distractor rejection process temporarily interfered with the target identification. When the observers knew the distractor identity, the rejection process started later than when they knew only the distractor category. These results suggest that the rejection process may operate at either the category or the individual-item level; however, the setting of the rejection level is not under the observers&apos; control.

The time series analysis of magnetoencephalographic (MEG) signals is very important both for basic brain research and for medical diagnosis and treatment. Here we discuss the crucial role of statistical memory effects (ME) in human brain functioning with photosensitive epilepsy (PSE). We study two independent statistical memory quantifiers that reflect the dynamical characteristics of neuromagnetic brain responses on a flickering stimulus of different colored combinations from a group of control subjects, which are contrasted with those from a patient with PSE. We analyze the frequency dependence of two memory measures for the neuromagnetic signals. The strong memory and the accompanying transition to a regular and robust regime of the signals&apos; chaotic behavior in the separate areas are characteristic for a patient with PSE. This particularly interesting observation most likely identifies the regions of the protective mechanism in a human organism against occurrence of PSE.

The detection of biological motion and the detection of emotion from this motion are important visual functions with obvious survival and social values. The perception of biological motion is remarkably robust, and numerous studies have shown that the emotional states of a person can be deduced from point-light biological motion. In the present study, we investigated the extent to which the detection of emotion from biological motion is linked to the explicit detection of human gait. Subjects performed gait detection and emotion detection for the same stimulus. The stimulus consisted of one coherent interval and one scrambled biological-motion interval, each of which contained one emotionally neutral and one emotional (angry or happy) walker. Significant correlations with gait detection performance were observed for anger detection but not necessarily for happiness detection, implying that the detection of anger may be more strongly linked to explicit gait detection. This leads to a hypothesis that differential dependence may reflect the differential behavioural meaning between anger and happiness detection; it may be more crucial to localise or identify a person with anger than happiness.

Recent studies on visual short-term memory have demonstrated that our visual system can retain only a few objects. However, it remains unclear whether this capacity limitation is because we forget the visual representation during a delay interval or because visual representations are formed for only a fraction of the visual objects from the beginning. The present study manipulated the delay interval to test these two possibilities. In the experiment, a sample display of six oriented bars was presented, followed by a 0-s or 1-s blank interval, and then by a test display with a cue. The participants reported the orientation of the sample stimulus at the cued location. The results showed that the measured visual capacity was about 3 items under both the 0-s and 1-s conditions. The measured capacity varied substantially across individuals. However, an individual's capacity under the 1-s condition was highly correlated with that under the 0-s condition. These results suggest that the capacity limit is originated from encoding rather than retention or retrieval processes.

It has been speculated that visual symmetry perception from dynamic stimuli involves mechanisms different from those for static stimuli. However, previous studies found no evidence that dynamic stimuli lead to active temporal processing and improve symmetry detection. In this study, four psychophysical experiments investigated temporal processing in symmetry perception using both dynamic and static stimulus presentations of dot patterns. In Experiment 1, rapid successive presentations of symmetric patterns (e.g., 16 patterns per 853 ms) produced more accurate discrimination of orientations of symmetry axes than static stimuli (single pattern presented through 853 ms). In Experiments 2-4, we confirmed that the dynamic-stimulus advantage depended upon presentation of a large number of unique patterns within a brief period (853 ms) in the dynamic conditions. Evidently, human vision takes advantage of temporal processing for symmetry perception from dynamic stimuli.

Here we discuss the remarkable role of the statistical memory effects in the human brain functioning at photosensitive epilepsy (PSE). We have analyzed three independent statistical memory quantifiers for the magnetoencephalographic ( MEG) signals. These quantifiers reflect the dynamical characteristics of neuromagnetic brain responses to a flickering stimulus of different color combinations. Results for a group of control subjects are contrasted with those from a patient with PSE. The emergence of the strong memory and the transition to a regular and robust regime of chaotic behavior of the signals in separate areas is characteristic for a patient with PSE versus a healthy brain.

The effects of prior experience often persist despite their futility. For example, vision scientists who have a long experience of a particular change blindness display are compelled to look at the location of the expected change even when they know that a change will not occur at the same location (Takahashi & Watanabe, 2008). Here, we investigated the types of experience that are required to form the persistent bias. Naive observers performed a typical change blindness task. Before the task, they repeatedly experienced the detection of a change in an identical display. The prior experience produced a gaze bias toward the experienced target. However, the bias decreased after the observers became aware that a change would not occur at the same location. These results suggest that prior experience immediately modulates visual search; however, repetitive detection was not sufficient for producing the persistent bias as observed in the case of vision scientists.

Adaptation to temporal asynchrony between senses (audiovisual and audiotactile) affects the subsequent simultaneity or temporal order judgment. Here, we investigated the effects of adaptation to temporal asynchrony between vision and touch. Participants experienced deformation of virtual objects with a fixed temporal lag between vision and touch. In subsequent trials, the visual and haptic stimuli were deformed with variable temporal lags, and the participants judged whether the stimuli became deformed simultaneously. The point of subjective simultaneity was shifted toward the adapted lag. No intermanual transfer of, the adaptation effect was, however, found. These results indicate that the perceptual simultaneity between vision and touch is adaptive, and is determined separately for each hand.

Most cognitive scientists know that an airplane tends to lose its engine when the display is flickering. How does such prior experience influence visual search? We recorded eye movements made by vision researchers while they were actively performing a change-detection task. In selected trials, we presented Rensink's familiar 'airplane' display, but with changes occurring at locations other than the jet engine. The observers immediately noticed that there was no change in the location where the engine had changed in the previous change-blindness demonstration. Nevertheless, eye-movement analyses indicated that the observers were compelled to look at the location of the unchanged engine. These results demonstrate the powerful effect of prior experience on eye movements, even when the observers are aware of the futility of doing so.

The relative visual positions of briefly flashed stimuli are systematically modified in the presence of motion signals (R. Nijhawan, 2002; D. Whitney, 2002). Previously, we investigated the two-dimensional distortion of relative-position representations between moving and. ashed stimuli. The results showed that the perceived position of a. ash is not uniformly displaced but shifted toward a single convergent point back along the trajectory of a moving object (K. Watanabe & K. Yokoi, 2006, 2007). In the present study, we examined the temporal dynamics of the anisotropic distortion of visual position representation. While observers fixated on a stationary cross, a black disk appeared, moved along a horizontal trajectory, and disappeared. A white dot was briefly flashed at various positions relative to the moving disk and at various timings relative to the motion onset/offset. The temporal emerging-waning pattern of anisotropic mislocalization indicated that position representation in the space ahead of a moving object differs qualitatively from that in the space behind it. Thus, anisotropic mislocalization cannot be explained by either a spatially or a temporally homogeneous process. Instead, visual position representation is anisotropically influenced by moving objects in both space and time.

To analyze the crucial role of fluctuation and relaxation effects for the function of the human brain we studied some statistical quantifiers that support the information characteristics of neuromagnetic brain responses (magnetoencephalogram, MEG). The signals to a flickering stimulus of different color combinations have been obtained from a group of control subjects which is then contrasted with those of a patient suffering photosensitive epilepsy (PSE). We found that the existence of the specific stratification of the phase clouds and the concomitant relaxation singularities of the corresponding nonequilibrium dynamics of the chaotic behavior of the signals in separate areas in a patient provide likely indicators for the zones which are responsible for the appearance of PSE. (c) 2007 Elsevier B.V. All rights reserved.

Various factors influence the perceived timing of visual events. Yet, little is known about the ways in which transient visual stimuli affect the estimation of the timing of other visual events. In the present study, we examined how a sudden color change of an object would influence the remembered timing of another transient event. In each trial, subjects saw a green or red disk travel in circular motion. A visual flash (white frame) occurred at random times during the motion sequence. The color of the disk changed either at random times (unpredictable condition), at a fixed time relative to the motion sequence (predictable condition), or it did not change (no-change condition). The subjects' temporal memory of the visual flash in the predictable condition was as veridical as that in the no-change condition. In the unpredictable condition, however, the flash was reported to occur closer to the timing of the color change than actual timing. Thus, an unpredictable visual change distorts the temporal memory of another visual event such that the remembered moment of the event is closer to the timing of the unpredictable visual change. (C) 2007 Elsevier Ltd. All rights reserved.

The relative visual positions of briefly flashed stimuli are systematically modified in the presence of motion signals. We have recently shown that the perceived position of a spatially extended flash stimulus is anisotropically shifted toward a single convergent point back along the trajectory of a moving object without a significant change in the perceived shape of the flash [Watanabe, K., & Yokoi, K. (2006). Object-based anisotropies in the flash-lag effect. Psychological Science, 17, 728-735]. In the previous experiment, the moving stimulus moved in both retinotopic and environmental coordinates. In the present study, we examined whether the anisotropic mislocalization depends on retinotopic or object motion signals. When the retinal image of a moving stimulus was rendered stationary by smooth pursuit, the anisotropic pattern of mislocalization was not observed. In contrast, when the retinal image of a stationary stimulus was moved by eye movements, anisotropic mislocalization was observed, with the magnitude of the mislocalization comparable to that in the previous study. In both cases, there was little indication of shape distortion of the flash stimulus. These results demonstrate a clear case of object-based mislocalization by retinotopic motion signals; retinotopic-not object-motion signals distort the perceived positions of visual objects after the shape representations are established. (C) 2007 Elsevier Ltd. All rights reserved.

Previous experimental and theoretical studies have suggested that two separate neural networks contribute to visuomotor learning of spatial sequences, one to the accuracy of performance and the other to the speed of performance (Nakahara et al. in J Cogn Neurosci 13:626-647, 2001). This study examined the influence of explicit knowledge of stimulus configuration (workspace) in visuomotor sequence learning. Twenty-eight right-handed subjects learned the sequences of button presses by trial and error (Hikosaka et al. in J Neurophysiol 76:617-621, 1996) in the course of two sessions. In the first session, both the number of completion failures (accuracy measure) and the performance time to complete a sequence (speed measure) decreased. In the second session, the workspace was rotated without notifying the subjects. About half the subjects remained unaware of the workspace rotation, and no transfer of learning occurred (i.e., neither accuracy nor speed of performance was preserved in the second session). The remaining subjects spontaneously noticed the rotation and they were able to use this knowledge to perform the task with less completion failures in the second session. However, the knowledge of workspace rotation did not decrease the performance time in the second session. The lack of influence of explicit knowledge on the speed of performance is consistent with the two-loop model of visuomotor sequence learning.

Spatial alignment of different face halves results in a configuration that mars the recognition of the identity of either face half (Young. Hellawell, & Hay. 1987). What would happen to the recognition performance for face halves that were aligned on the retina but were perceived as misaligned, or were misaligned on the retina but were perceived as aligned? We used the 'flash-lag' effect (Nijhawan, 1994) to address these questions. We created chimeras consisting of a stationary top half-face initially aligned with a moving bottom half-face. Flash-lag chimeras were better recognized than their stationary counterparts. However when flashed face halves were presented physically ahead of moving halves thereby nulling the flash-lag effect, recognition was impaired. This counters the notion that relative movement between the two face halves per se is sufficient to explain better recognition of flash-lag chimeras. Thus. the perceived spatial alignment of face halves (despite retinal misalignment) impairs recognition. while perceived misalignment (despite retinal alignment) does not. (c) 2006 Elsevier Ltd. All rights reserved.

Olivers and van der Helm (1998) showed that symmetry-defined visual search (for both symmetry and asymmetry) requires selective spatial attention. We hypothesize that an attentional set for the orientation of a symmetry axis also is involved in symmetry-defined visual search. We conducted three symmetry-defined visual search experiments with manipulations of the axis of symmetry orientations, and performance was better when the axis orientations within the search array were uniform, rather than a mixture of two orientations, and the attentional set for the axis orientation could be kept. In addition, search performance when the target was defined by the presence of symmetry was equivalent to that when the target was defined by a difference of symmetry axis orientation. These results suggest that attentional set for axis orientation plays a fundamental role in symmetry-defined visual search. Copyright 2006 Psychonomic Society, Inc.

Although the detection of visual bilateral symmetry has been claimed to be highly efficient, the possible involvement and function of visual memory in such efficient mechanisms has rarely been examined. We hypothesized that symmetry perception is rapid, as it can be achieved from rapidly decaying information of visible persistence. To test this hypothesis, we employed a temporal integration paradigm. A symmetric dot pattern was randomly divided into two asymmetric patterns and presented successively with a blank screen presented between patterns. Observers could detect symmetry when the two patterns were presented close in time (Experiment 1), indicating that observers perceived symmetry presumably utilizing visible persistence. In addition, the inverse-intensity effect of visible persistence (Di Lollo & Bischof, 1995) was evident in our temporal integration task of symmetry (Experiment 2). The results of the current study clearly demonstrate that the detection of symmetry can be achieved based on the visible persistence. The large capacity and high spatial precision of visible persistence might be adequate for the rapid and spatially global encoding of visual symmetry.

Visual motion signals distort the perceived positions of briefly presented stimuli; a briefly-flashed, stationary stimulus appears spatially displaced in the direction of a nearby motion. The present study examined the role of the visual awareness of motion in the motion-induced position shift by using exclusive dominance and suppression of binocular rivalry. Observers dichoptically viewed a flickering radial checkerboard and two sinusoidal gratings that drifted vertically in opposite directions. When observers viewed exclusively either the checkerboard or motion stimulus, two horizontal lines were flashed, one for each side of the rivalry stimulus. During the exclusive dominance of the grating motion, the lines appeared to shift in the directions of the nearby motions. The position shift was identical to that during non-rivalry, monocular viewing of the motion stimulus. However, when the grating motions were completely suppressed, no position shift was observed. These results demonstrate that the motion-induced position shift depends on the visual awareness of motion. (c) 2005 Elsevier Ltd. All rights reserved.

When subjects localize a flash relative to another stationary stimulus, the flash appears displaced in the direction of nearby motion signals (position capture; Whitney and Cavanagh, 2000 Nature Neuroscience 3 954-959). Our previous study had suggested that the position capture is larger for a flash presented ahead of a moving stimulus than for a flash behind it (Watanabe et at, 2003 Perception 32 545-559). In the present study, I investigated the spatial asymmetry of position capture. Experiment I demonstrated that asymmetric position capture occurs primarily in a moving-object-centered coordinate. Experiment 2 showed evidence that the asymmetric position capture operates after individuation of single visual objects. Finally, experiment 3 demonstrated that, when attention was reduced with a dual-task procedure, the asymmetric position capture increased. These results suggest that the spatial asymmetry of position capture occurs without attention but the spatial bias can be reduced by attention. Therefore, the underlying mechanism for the asymmetric spatial bias may be different from attentive tracking (Cavanagh, 1992 Science 257 1563 - 1565) and mislocalization during smooth pursuit (Brenner et al, 2001 Vision Research 412253 - 2259).

We investigated the dynamical characteristics of neuromagnetic responses by recording magnetoencephalographic (MEG) signals to equiluminant flickering stimulus of different color combinations from a group of control subjects, and from a patient with photosensitive epilepsy. By wavelet based time-frequency analysis, we showed that two distinct neuromagentic responses corresponding to stimulus frequency and its time delayed first harmonic were found in control subjects, whereas no harmonic response was obtained for the patient. We applied a battery of methods (sample entropy measuring signal complexity and index of smoothness measuring determinism) based on nonlinear dynamical system theory in conjunction with bootstrapping surrogate analysis. The results suggested that a significant nonlinear structure was evident in the MEG signals for control subjects, whereas nonlinearity was not detected for the patient. In addition, the couplings between distant cortical regions were found to be greater for control subjects. The important role of combinational chromatic sensitivity in sustained cortical excitation was also confirmed. These findings lead to the hypothesis that the healthy human brain is most likely equipped with significantly nonlinear neuronal processing reflecting an inherent mechanism defending against hyper-excitation to chromatic flickering stimulus, and such nonlinear mechanism is likely to be impaired for a patient with photosensitive epilepsy.

A flashed stimulus is perceived as spatially lagging behind a moving stimulus when they are spatially aligned. When several elements are perceptually grouped into a unitary moving object, a flash presented at the leading edge of the moving stimulus suffers a larger spatial lag than a flash presented at the trailing edge (K. Watanabe, R. Nijhawan, B. Khurana, & S. Shimcjo, 2001). By manipulation of the flash onset relative to the motion onset, the present study investigated the order of perceptual operations of visual motion grouping and relative visual localization. It was found that the asymmetric mislocalization was observed irrespective of physical and/or perceptual temporal order between the motion and flash onsets. Thus, grouping by motion must be completed to define the leading-trailing relation in a moving object before the visual system explicitly represents the relative positions of moving and flashed stimuli.

There are significant neural transmission and processing delays within the nervous system. How then are behaviours observed both in nature and high-speed ball games, which require temporal accuracy to within several milliseconds, possible? Until recently, most investigators attributed the observed success in interceptive behaviours to learning or prediction built into motor programs that take these delays into account. Several investigators have proposed, however, that sensory mechanisms also contribute to compensation. Sensory compensation is particularly important when moving objects are the targets of interceptive behaviour, as in this case neural delays in the visual system could lead to errors in the communication of crucial position information of the object of interest. However, given the biological significance of visual motion the visual system could have evolved neural pathways optimized for the rapid transmission of motion signals. Alternatively, the visual system could take a sample of visual motion and compensate for the delays through prediction based on the sample. This mechanism is the visual analogue of the previously proposed "internal forward model" for motor control. We conducted four experiments using the flash-lag effect to ask if the nervous system is naturally geared to processing moving items with a speed greater than stationary flashes. Our results show that the nervous system does not process moving items more quickly than stationary flashes.

The prospect of reward evoked by external stimuli is a central element of goal-oriented behavior. To elucidate behavioral effects of reward expectation on saccade latency, we employed a visually guided saccade task with asymmetrical reward schedule. The monkey had to make an immediate saccade to a peripheral visual target in every trial, but was rewarded for a correct saccade to only one of four possible target positions. Reward availability was predictable on the basis of the spatial position of the target throughout a daily session. Compared with the condition where all positions were rewarded with a smaller amount, the mean saccade latency in the asymmetrical reward schedule was significantly shorter when the saccade was made toward the position associated with reward than when it was directed to no-reward positions. Furthermore, a divergence-point analysis on cumulative latency distributions showed that the expectation of reward facilitated saccades at all latency ranges. In contrast, the expected lack of reward delayed the initiation of saccades with latencies longer than about 200 ms, irrespective of whether the saccade was made to a position orthogonal or opposite to the reward position. For saccades with latencies of more than approximately 240 ms, an additional delay was observed when the saccade was made to a position opposite, as compared to orthogonal, to the reward position. These results suggest that the facilitation by predictive reward is mediated by a preparatory process that is location-specific, whereas the inhibition by the absence of reward takes about 200 ms after the target onset to become effective and is initially location nonspecific but turns location-specific over time.

We tested the hypothesis that frontal eye field (FEF) visual activity integrates visual information with a template of a target by examining whether a target that is not present in a search display influences the target selection in FEF. Neural activity was recorded in FEF of macaque monkeys performing visual search for a singleton target defined by color or direction of motion. The target remained constant throughout, but not across experimental sessions. Trials with distractors dissimilar to the target were interleaved with trials with distractors similar to the target. The hypothesis was tested by measuring the magnitude of activity in randomly interleaved trials with the target absent and only distractors in the display. We found that the response to the distractors was significantly greater when presented with displays consisting of distractors that resembled the absent target than when presented with displays consisting of distractors most different from the absent target. The influence of target-distractor similarity on FEF activity was also observed when the target was present, as reported previously. These data suggest that a template of the absent target can influence the selection process in FEF. This provides more direct evidence that FEF integrates visual information and knowledge of the target to determine the goal of a saccade.

When visual changes are accompanied by visual transients, such as in the case of saccades, eye blinks, and brief flickers, they often go unnoticed; this phenomenon is called change blindness (Rensink, R. A. (2002). Change detection. Annual Review of Psychology 53, 245; Simons, D. J., & Levin, D. T. (1997). Change blindness. Trends in Cognitive Sciences 1, 261). Change blindness occurs even when the position of visual transients does not cover the location of the change (as in the 'mudsplash' paradigm) (O'Regan, J. K., Rensink, R. A., & Clark, J. J. (1999). Change blindness as a result of 'mudsplashes'. Nature 398, 34). By using a simplified mudsplash display, the present study investigated whether change blindness depends on (a) the timing of visual transients, and (b) the task that observers perform. Eight Gabor elements with random orientations were presented. One element (target) was rotated 45 degrees clockwise or counterclockwise without a temporal gap. High contrast visual transients, not overlapping with the elements, appeared at various times with respect to the target change. Observers reported where the change was (change localization), or in which direction the target rotated (change identification). Change localization was impaired primarily when the onset of the transient was at or after the change. In contrast, change identification was impaired mainly when the transient preceded the change. These results suggest that change localization and change identification are mediated in part by different mechanisms. (C) 2003 Elsevier Science B.V. All rights reserved.

Perceived positions of flashed stimuli can be altered by motion signals in the visual field-position capture (Whitney and Cavanagh, 2000 Nature Neuroscience 3 954-959). We examined whether position capture of flashed stimuli depends on the spatial relationship between moving and flashed stimuli, and whether the phenomenal permanence of a moving object behind an occluding surface (tunnel effect; Michotte 1950 Acta Psychologica 7 293-322) can produce position capture. Observers saw two objects (circles) moving vertically in opposite directions, one in each visual hemifield. Two horizontal bars were simultaneously flashed at horizontally collinear positions with the fixation point at various timings. When the movement of the object was fully visible, the flashed bar appeared shifted in the motion direction of the circle. But this position-capture effect occurred only when the bar was presented ahead of or on the moving circle. Even when the motion trajectory was covered by an opaque surface and the bar was flashed after complete occlusion of the circle, the position-capture effect was still observed, though the positional asymmetry was less clear. These results show that movements of both visible and 'hidden' objects can modulate the perception of positions of flashed stimuli and suggest that a high-level representation of 'objects in motion' plays an important role in the position-capture effect.

Excessive cortical excitation due to visual stimulation often leads to photosensitive epilepsy. Here we demonstrate that even in normal subjects, prolonged stimulation with low-luminance chromatic (equiluminant) flicker evokes neuromagnetic activity in the primary visual cortex, which develops slowly (up to 1000 ms) and depends on the color combination of flicker. This result suggests that chromatic sensitivity is a critical factor of cortical excitation, which can be amplified over time by a flickering stimulus. We further show that transient activity occurs in the parieto-occipital sulcus as early as 100-400 ms after flicker onset, which is negatively correlated with the later occipital activity. The early parieto-occipital activity may reflect a defensive mechanism that suppresses cortical hyperactivity due to chromatic flicker.

Moving stimuli cause the position of flashed stimuli to appear shifted in the direction of motion (position capture). To examine whether position capture depends on low-level motion interactions or perception of integrated object motion, we employed a slit-view display. Two line-drawn diamonds translated horizontally in opposite directions, one above and one below the fixation cross, either behind an occluding surface with a narrow slit or without occluding surface. When the diamonds were in vertical alignment, two vertical bars were flashed, one in the center of each diamond. In the slit-view condition, the diamonds were visible through a 4-, 2-, or 1-pixel vertical slit; the width of the flashed bars always matched the width of the slit. Even though the horizontal component of physical motion was greatly reduced or absent in the slit-view conditions, observers perceived diamonds moving behind the occluding surface. Furthermore, the position of the flashed bar was captured by the moving diamonds such that each bar appeared shifted in the direction of perceived motion. We conclude that the position capture reported here has a component based on high-level motion processing that is responsible for dynamically integrating object motion and shape. (C) 2002 Elsevier Science Ltd. All rights reserved.

When a visual stimulus is flashed at a given location the moment a second moving stimulus arrives at the same location, observers report the flashed stimulus as spatially lagging behind the moving stimulus (the flash-lag effect). The authors investigated whether the global configuration (perceptual organization) of the moving stimulus influences the magnitude of the flash-lag effect. The results indicate that a flash presented near the leading portion of a moving stimulus lags significantly more than a flash presented near the trailing portion. This result also holds for objects consisting of several elements that group to form a unitary percept of an object in motion. The present study demonstrates a novel interaction between the global configuration of moving objects and the representation of their spatial position and may provide a new and useful tool for the study of perceptual organization.

When subjects make a quick saccade to one of two stimuli that are presented closely and simultaneously in the peripheral visual field, their eyes often land at a midpoint somewhere between the stimuli (saccadic averaging), The present study investigates whether and how the inhibition-of-return phenomenon (IOR; slower reaction times for the previously attended locations) influences spatial parameters of averaging saccades. Subjects were asked to quickly move their eyes toward one of two stimuli that were presented closely and simultaneously. Most subjects showed a clear tendency toward saccadic averaging. When an uninformative cue was presented 600 ms before the two stimuli (long enough to produce IOR), saccadic averaging still occurred but the saccade landing locations were biased toward the uncued location. Thus, the present study demonstrates that the mechanisms responsible for IOR affect the metrics of averaging saccades and suggests that IOR can be manifested not only in the temporal aspects but also in the spatial aspects of oculomotor behaviors.

During optokinetic nystagmus (OKN) the mean eye position of gaze (the beating field) shifts in the direction of the fast phases. The function of this shift may be to re-orient the eyes in the direction of self-motion which optic flow implies tin-coming field). This idea leads to the hypothesis that visual attention may be directed toward the In-coming field. In Experiment 1, subjects detected a visual flash presented against unidirectional field motion. The OKN beating field was shifted toward the In-coming field, and manual reaction times were shorter when the target appeared in the In-coming field. Experiment 2 revealed that this In-coming field advantage occurred even when OKN land thus the mean eye-position shift) was suppressed. Subsequent experiments showed that the In-coming field advantage is not due to a local motion interaction (Experiment 3), survives subject's voluntary allocation of attention (Experiment 4), and develops over less than 320 ms after the onset of the motion held (Experiment 5). These results suggest that unidirectional field motion tends to automatically shift Visual attention toward the In-coming held. (C) 2001 Elsevier Science Ltd. All rights reserved.

There is significant evidence for higher-level cortical control of pupillary responses to visual stimuli, suggesting that factors other than luminance changes may induce a pupillary response. In the present study, the pupillary responses to equiluminant flickering stimuli in a range of 3-13 Hz were examined. Flicker stimuli included color-black (luminance-modulated) and color-color (hue-modulated) flicker. Equiluminance was determined both by objective luminance measures as well as by subjective, perceptual equiluminance for each subject. For both objectively and subjectively equiluminant flicker, significant, sustained pupillary constrictions were recorded. The magnitude of these responses was sensitive to both color and frequency parameters; red-blue color-paired flicker consistently produced the strongest constrictions. These responses occurred even when the nicker was of a lower luminance, both physically and perceptually, than a preceding nonflickering color, indicating that chromatic rather than luminance-sensitive mechanisms are involved in this response. Interestingly, the color- and frequency-sensitivity of constriction parallels those of flickers which maximally stimulate photosensitive epileptic patients, raising the possibility that chromatic response may be a factor in photosensitivity.

Three sets of new findings with regard to modulation of visual perception by auditory stimuli are reviewed. First, we show that visual temporal resolution can be either improved or deteriorated by accompanying sounds, depending on the sequence and delay among the auditory and visual stimuli. Second, a single visual flash can be perceived as multiple flashes when accompanied by multiple sounds. Third, an ambiguous motion display consisting of two objects moving toward each other is perceived as streaming with or without an unsynchronized sound, but as bouncing with a synchronized sound. Based on these findings, we argue, against the traditional belief of visual dominance, that audition can modify vision particularly when it provides strong transient signal(s).

Objects flashed in alignment with moving objects appear to lag behind [Nijhawan, 1994 Nature (London) 370 256-257]. Could this 'flash-lag' effect be due to attentional delays in bringing flashed items to perceptual awareness [Titchener, 1908/1973 Lectures on thp Elementary Psychology of Feeling and Attention first published 1908 (New York: Macmillan); reprinted 1973 (New York: Arno Press)]? We overtly manipulated attentional allocation in three experiments to address the following questions: Is the flash-lag effect affected when attention is (a) focused on a single event in the presence of multiple events, (b) distributed over multiple events, and (c) diverted from the flashed object? To address the First two questions, five rings, moving along a circular path, were presented while observers attentively tracked one or multiple rings under four conditions: the ring in which the disk was flashed was (i) known or (ii) unknown (randomly selected from the set of five); location of the flashed disk was (i) known or (ii) unknown (randomly selected from ten locations). The third question was investigated by using two moving objects in a cost-benefit cueing paradigm. An arrow cued, with 70% or 80% validity, the position of the flashed object. Observers performed two tasks: (a) reacted as quickly as possible to flash onset; (b) reported the flash-lag effect. We obtained a significant and unaltered flash-lag effect under all the attentional conditions we employed. Furthermore, though reaction times were significantly shorter for validly cued flashes, the flash-lag effect remained uninfluenced by cue validity, indicating that quicker responses to validly cued locations may be due to the shortening of post-perceptual delays in motor responses rather than the perceptual facilitation. We conclude that the computations that give rise to the flash-lag effect are independent of attentional deployment.

A human observer can smoothly pursue her/his own voluntarily moved hand with the eyes in total darkness. The effects of a perceived stationary surface during ocular pursuit of the invisible hand were investigated. The task was to track the invisible hand smoothly with the eyes in a Ganzfeld (experiment 1), with a stationary visual surface in the light (experiment 2), or with a solid stationary surface in total darkness (experiment 3). It was found that smooth pursuit of the invisible hand occurred in the Ganzfeld as well as in total darkness, but was replaced by frequent saccades when a stationary surface was perceived through either the visual or the tactile sense. The results obtained with a Ganzfeld suggest that light alone does not prevent smooth pursuit of the invisible hand, and those obtained with a stationary surface suggest that perception of such a surface prevents smooth pursuit of the invisible hand and evokes saccades, regardless of the sense modality.

This contribution deals with two major issues on visual/spatial attention. One is the issue of facilitation and inhibition
that is, under what conditions facilitatory modulation occurs, and under what other conditions inhibitory modulation occurs. The other issue is that of spatial representation
in what type of spatial representation do these modulations occur, retinotopic or environmental? In the first half of this article, we review the latest studies employing various psychophysical measures to assess spatially-selective modulation of visual information processing. We also summarize our latest results on reaction time, indicating a dissociation of two visual functions, detection/orientation and feature discrimination. Based on these chunks of knowledge, we raise a question about the spatial coordinate system in which the facilitatory and/or inhibitory modulations occur. We then provide results of two reaction-time experiments which partly answer the question.