<title>Abstract</title>We investigated the neural correlates underpinning synchronized movement in rowers using a neural index for social interaction termed the phi complex. Phi 1 and phi 2 indicate the enhancement and reduction of mirror neuron activation, respectively. We hypothesized that in a leader–follower relation, followers would exhibit a larger phi 2 power than leaders due to enhanced mirror neuron activation by the followers to accurately mimic their partner’s movements. We also expected that brain activation underlying social interaction would be enhanced during synchronization. Although phi 2 was not modulated by role (leader vs. follower) or condition (usual-pair vs. unusual-pair), the statistical analysis suggested the relationship between the magnitude of phi 2 and empathetic ability in followers in the usual-pair condition. Given that the activation of the mirror neuron system underlies empathic ability, it is plausible that the participants used the mirror neuron system to follow the movement of a usual partner. In other words, the leader in the synchronization did not need to use the mirror neuron system, which was consistent with the result of a larger phi 1 for leading than following the movement. These results suggest that the neural correlates of empathy may be used to synchronize with partners as the follower.

We investigated if viewing cute pictures could improve fine motor skills and prolong quiet eye (QE) duration. QE is a gaze phenomenon, and its duration (i.e., the period between fixation onset preceding a critical movement and fixation offset) is thought to represent attention control. As it has been reported that QE duration is longer for expert athletes than for novice athletes in various sports and becomes shorter even for experts who choke under pressure during games, resulting in performance deterioration, QE prolongation is important to prevent choking under pressure. Separately, several studies have confirmed that viewing cute pictures can induce focal attention, thus improving performance in fine motor tasks. We hypothesized that viewing cute pictures may modulate attention control and prolong QE duration. We also tested if the beneficial effects of viewing cute pictures could be obtained in a high-pressure situation in which participant performance was evaluated by an experimenter. We used a fine-motor task requiring participants to use a pair of tweezers to remove 12 small pieces from holes in a game board. We randomly assigned participants to either the baby-animal pictures group or the adult-animal pictures group, based on pictures viewed prior to the task. Participants executed the task in a pre-test, post-test, and pressure test. In both the post-test and the pressure test, participants viewed seven photographs of either baby animals or adult animals before execution of the task. In accordance with previous research, task precision increased after viewing pictures of baby animals in both the post-test and pressure test. Furthermore, QE duration was also prolonged after viewing cute pictures in the post-test, but not in the pressure test. Neither performance improvement nor QE prolongation was found after viewing pictures of adult animals. These results suggested that simply viewing cute pictures could prolong QE duration without pressure and might provide a beneficial effect on performance, even in a high-pressure situation.

If you know that you are the author of a freely chosen action and that you bear responsibility for its outcome, then you are said to have "a sense of agency." When there is a delay between action and outcome, this response must be remembered if you are to learn from the experience. Previous studies have shown that the Stimulus-Preceding Negativity (SPN) recorded during the delay interval is larger under conditions that foster a sense of agency. In an EEG experiment (N = 27), we confirmed that the SPN is larger when participants have a choice between two responses in a gambling task as compared to when there is only a single button and the computer determines the monetary outcome. This SPN agency effect was largest over right prefrontal cortex and it did not vary significantly between trial blocks in which only gains or only losses were possible. Participants in a second experiment (N = 26) performed the same task while activity in anterior insular cortex, a known SPN generator, was measured via functional magnetic resonance image (fMRI). An essentially identical pattern of results was obtained: Activity was greater on choice than no-choice trials, especially for the right hemisphere, and no effect of contextual valence was observed. Although parallel observations such as these cannot warrant causal inference, our findings are consistent with the assumption that anterior insular cortex contributes to the effect of agency on the SPN.

Abstract. Athletes who squeezed a ball with their left hand immediately prior to execution of sports activities did not show performance deterioration under severe pressure ( Beckmann, Gröpel, &amp; Ehrlenspiel, 2013 ). This result has been explained by priming of the dominant right hemisphere. However, it remains unclear what variables have the greatest effect on asymmetrical brain activity (e.g., duration and strength of ball squeezing). We hypothesized that squeezing a ball harder for a longer period might lead to stronger asymmetrical activity because motor-related areas would have increased activation due to the more forceful movement. We used electroencephalograms (EEGs) to investigate the hemispheric asymmetry of brain activity produced by squeezing a ball with a unilateral hand. EEGs were assessed during a baseline period as well as in eight experimental conditions wherein the strength and duration of the ball squeeze were manipulated. Our results showed that right-hemispheric-dominant brain activation was maximized when participants squeezed with their left hand a ball that had an internal pressure of 100 hPa for 90 s or 20 hPa for 30 s. Moreover, squeezing the ball with 100 hPa internal pressure for 90 s created a prominent interhemispheric asymmetry of cortical activity. We suspect that squeezing a ball strongly for a long period might be helpful in dealing with “choking” under pressure by producing greater right-hemispheric activation. This result could help improve simple methods for competitive athletes to reduce the likelihood of exhibiting choking behavior that could be practiced with minimal effort, even during short breaks during a game.

Previous findings have reported that track and field athletes may monitor and utilize internal information, including anxiety level, suggesting that the ability to inwardly monitor one's own functioning and utilize anxiety are required to achieve superior performance. Performance monitoring has been investigated using two event-related potential components
the error (-related) negativity (Ne/ERN) and error positivity (Pe). It is unknown whether performance monitoring differs among various types of athletes. It has also been reported that Ne/ERN amplitude is increased in individuals who are more anxious and the prevalence and effect of anxiety also differs among various types of athletes. In this study, we recorded both Ne/ERN and Pe from long-distance runners (n = 24) and sprinters (n = 24) while they were performing a spatial Stroop task under motivation and no motivation conditions. We also collected scores on the Sport Competitive Anxiety Test (SCAT). Mean error rate on incongruent trials was lower in the motivation condition than in the no motivation condition. There was neither group effect, nor condition effect found in Ne/ERN amplitude. However, for the long-distance runners, Pe amplitude was larger in the motivation condition than in the no motivation condition. We also investigated the relationships between Ne/ERNs and individual differences in performance anxiety using the SCAT. A multiple linear regression analysis in the motivation condition revealed an interaction between type of runner and SCAT scores, indicating that long-distance runners with higher SCAT scores showed larger Ne/ERN amplitudes whereas the sprinters with high SCAT scores tended to exhibit smaller Ne/ERN amplitudes. Our findings provide further evidence that performance monitoring differs across various types of athletes.

Little is known about the effects of the motivational significance of errors in Go/No-go tasks. We investigated the impact of monetary punishment on the error-related negativity (ERN) and error positivity (Pe) for both overt errors and partial errors, that is, no-go trials without overt responses but with covert muscle activities. We compared high and low punishment conditions where errors were penalized with 50 or 5 yen, respectively, and a control condition without monetary consequences for errors. Because we hypothesized that the partial-error ERN might overlap with the no-go N2, we compared ERPs between correct rejections (i.e., successful no-go trials) and partial errors in no-go trials. We also expected that Pe amplitudes should increase with the severity of the penalty for errors. Mean error rates were significantly lower in the high punishment than in the control condition. Monetary punishment did not influence the overt-error ERN and partial-error ERN in no-go trials. The ERN in no-go trials did not differ between partial errors and overt errors; in addition, ERPs for correct rejections in no-go trials without partial errors were of the same size as in go-trial. Therefore the overt-error ERN and the partial-error ERN may share similar error monitoring processes. Monetary punishment increased Pe amplitudes for overt errors, suggesting enhanced error evaluation processes. For partial errors an early Pe was observed, presumably representing inhibition processes. Interestingly, even partial errors elicited the Pe, suggesting that covert erroneous activities could be detected in Go/No-go tasks.

The Monty Hall Dilemma (MHD) poses a counterintuitive probabilistic problem to the players of this game. In the MHD task, a participant chooses one of three options where only one contains a reward. After one of the unchosen options (always no reward) is disclosed, the participant is asked to make a final decision: either change to the remaining option or stick with their first choice. Although the probability of winning if they change is higher (2/3) compared to sticking with their first choice (1/3), most people stick with their original selection and often lose. In accordance with previous research, repetitive exposure to the MHD task increases the change behavior without any obvious understanding of the mathematical reasons why changing increases their chance of being rewarded. We recorded the stimulus-preceding negativity (SPN), an ERP that might reflect the informative value of the feedback. In the second half of the task, feedback was predicted to be less informative because learning had taken place. Indeed, the SPN amplitude became smaller over the frontal region. Also, the SPN amplitude was larger for change than for stick trials. These results suggest that learning in the MHD might be manifest in affective-motivational anticipation as indicated by the SPN.

We investigated how aerobic exercise during encoding affects hippocampus-dependent memory through a source memory task that assessed hippocampus-independent familiarity and hippocampus-dependent recollection processes. Using a within-participants design, young adult participants performed a memory-encoding task while performing a cycling exercise or being seated. The subsequent retrieval phase was conducted while sitting on a chair. We assessed behavioral and event-related brain potential measures of familiarity and recollection processes during the retrieval phase. Results indicated that source accuracy was lower for encoding with exercise than for encoding in the resting condition. Event-related brain potential measures indicated that the parietal old/new effect, which has been linked to recollection processing, was observed in the exercise condition, whereas it was absent in the rest condition, which is indicative of exercise-induced hippocampal activation. These findings suggest that aerobic exercise during encoding impairs hippocampus-dependent memory, which may be attributed to inefficient source encoding during aerobic exercise.

A growing number of studies conducted over the past decade have demonstrated that greater aerobic fitness is associated with superior cognitive control in preadolescent children. Several studies have suggested that the relationship between fitness and cognitive control may be attributed to differential reliance on proactive vs. reactive cognitive control modes. However, this contention has remained speculative, and further studies are needed to better elucidate this relationship. We designed the present study to test the hypothesis that use of cognitive control modes would differ as a function of childhood fitness. We compared performance of lower-fit and higher-fit children on a modified AX-continuous performance task, commonly used to examine shifts in the use of proactive and reactive control, along with cue-P3 and contingent negative variation (CNV) of event-related brain potentials (ERPs). Results indicated that higher-fit children exhibited greater response accuracy for BX (non-target cue target probe) relative to AY (target cue - non-target probe) trials, whereas lower-fit children had comparable response accuracies for AY and BX trials. Because enhanced BX performance and impaired AY performance may be attributed to the proactive use of context information, these results suggest that greater childhood fitness is associated with more effective utilization of proactive control. Higher-fit children also exhibited larger cue-P3 amplitude and smaller CNV amplitude for BX relative to AY trials, with no such effect of trial type in lower-fit children. These ERP results suggest that greater fitness is associated with more effective utilization of cue information and response preparation more appropriate to trial type, supporting the behavioral findings. The present study provides novel insights into the relationship between fitness and cognition from the perspective of cognitive control mode during task preparation.

Several studies have claimed that the positive association between childhood fitness and cognitive control is attributable to differences in the child's cognitive control strategy, which can involve either proactive or reactive control. The present study tested this hypothesis by manipulating the probability of trial types during a modified flanker task. Preadolescent children performed mostly congruent and mostly incongruent conditions of the flanker task, with post-error task performance and error negativity/error-related negativity (Ne/ERN) being assessed. Results indicated that greater aerobic fitness was related to greater post-error accuracy and larger Ne/ERN amplitudes in the mostly congruent condition. These findings suggest that higher-fit children might be able to transiently upregulate cognitive control by recruiting reactive control in the mostly congruent condition. Further, greater fitness was related to greater modulation of Ne/ERN amplitude between conditions, suggesting that higher-fit children engaged in more proactive control in the mostly incongruent condition. This study supports the hypothesis that greater childhood fitness is associated with a more flexible shift between reactive and proactive modes of cognitive control to adapt to varying task demands.

Affect and motivation influence the error-related negativity (ERN) elicited by full errors; however, it is unknown whether they also influence ERNs to correct responses accompanied by covert incorrect response activation (partial errors). Here we compared a neutral condition with conditions, where correct responses were rewarded or where incorrect responses were punished with gains and losses of small amounts of money, respectively. Data analysis distinguished ERNs elicited by full and partial errors. In the reward and punishment conditions, ERN amplitudes to both full and partial errors were larger than in the neutral condition, confirming participants' sensitivity to the significance of errors. We also investigated the relationships between ERN amplitudes and the behavioral inhibition and activation systems (BIS/BAS). Regardless of reward/punishment condition, participants scoring higher on BAS showed smaller ERN amplitudes in full error trials. These findings provide further evidence that the ERN is related to motivational valence and that similar relationships hold for both full and partial errors. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license

Humans tend to be conservative and typically will retain their initial decision even if an option to change is provided. We investigated whether the stimulus-preceding negativity (SPN), an event-related potential associated with the affective-motivational anticipation of feedback in gambling tasks, represents the strong response tendency to retain an initial decision. We compared SPNs in three different card-gambling tasks wherein the participants were given the opportunity to change their initial decision after they chose one of three cards. In two of these tasks, the winning probability was equiprobable (1/3 and 1/2, respectively) whether or not the participants changed their initial decision. However, in the Monty Hall dilemma task, changing the initial decision stochastically doubled the probability of winning (2/3) compared with retaining (1/3). In this counterintuitive probabilistic dilemma task, after the participant chose an option among three cards, a nonreward (losing) option is revealed. Then, the participants are offered a chance to change their mind and asked to make their final decision: to retain their initial choice or change to the alternate option. In all tasks, maintenance of previous behaviors was observed, although the rate of retaining earlier choices tended to be lower in the Monty Hall dilemma task than in the other two tasks. The SPNs were larger on retain trials than on change trials irrespective of task. These results suggest that underlying brain activities associated with the strong tendency to retain the initial decision can be observed by the SPN and thus it reflects expectancy of outcomes in terms of self-chosen behaviors.

The skilled performance positivity (SPP) emerges approximately 450 ms after button presses in a skilled performance task (SPT) where the participant is required to initiate a visual sweep with a left-hand button press and then stop it with a right-hand button press within a predetermined time frame (ranging from 40 to 60 ms). The SPP has been thought to represent appraisal of performance results independent of the reafferent activity, and reported to reduce in amplitude following inaccurate timing performance. We hypothesized that reduced SPP on incorrect trials merely indicates superimposition of the feedback-related negativity (FRN) that is elicited by negative outcomes, because the right-hand button press not only stops the visual sweep but also presents visual feedback. Further, we assumed that the SPP essentially represents a P300 elicited by the visual feedback. To address these questions, we compared the SPT condition and a delayed-feedback (DFB) condition where feedback was presented approximately 1 s after the left-hand button press. We observed the SPP only in the SPT condition, and found feedback-elicited P300s in the DFB condition. Both of these positivities shared a similar scalp distribution. We also replicated the reduced SPP on incorrect trials that shared a similar topography with the FRN elicited by the negative feedback. According to these findings, it is reasonable to conclude that the SPP represents the feedback-elicited P300, and after incorrect performance an FRN is superimposed on it. (C) 2015 Elsevier B.V. All rights reserved.

:There is a widely accepted notion that movement elements are assembled prior to movement execution in a central motor programming stage. However, it is not clear how this stage is structured-whether it is a unitary stage allowing different motor parameters to cross talk or whether there are several independent processes dealing with each motor parameter. We addressed this question by orthogonally manipulating two movement-related factors: response sequence complexity and movement duration. Both factors yielded main effects on reaction time but no interaction. Additive effects of both factors on the onsets of response- but not stimulus-synchronized lateralized readiness potentials suggest separable motoric loci of sequence complexity and duration. These findings are at variance with the notion of a unitary movement programming stage.

In this chapter we provide additional insight into the association between aerobic fitness and cognitive flexibility in preadolescent children. We compared lower-fit and higher-fit children&#146
s task performance during the Trail Making Test (TMT). The TMT consists of two parts. TMT-A requires participants to draw a line connecting 25 randomly positioned numbers in numerical order, while TMT-B asks them to draw a line connecting numbers and letters in an alternating order. That is, the TMT-B necessitates greater cognitive flexibility than the TMT-A. Analyses revealed that higher-fit children exhibited superior task performance relative to lower-fit children for the TMT-A, corroborating previous findings indicating the general nature of the relationship between fitness and cognition in preadolescent children. In contrast, task performance did not differ between the fitness groups for the TMT-B. Thus, the positive association between aerobic fitness and cognitive flexibility disappeared, likely because the cognitive task was too difficult for preadolescent children. This result indicates that task difficulty affects the association between fitness and cognitive control during childhood.

In the first part of this chapter we review the schema theory of motor control (Schmidt 1975). We emphasize its two main components, generalized motor programs (GMP) and parameterization. Accumulated evidence suggests the independence of GMP and parameterization. However, there is no consensus whether or not they proceed in a fixed order with the assembly of GMPs first, followed by parameterization. These questions could be studied in more detail by using event-related brain potentials. We review this approach in the second part.

We investigated the effect of punishment on performance monitoring by having participants perform a spatial Stroop task in both a non-punishment (i.e. control) and a punishment condition where they received one of two unpleasant noises (two 90 dB recordings of scratching a blackboard with nails) one second after an erroneous response. We examined both the error-related negativity (ERN) and the error positivity (Pe) amplitudes across conditions as well as correlations among scores on the behavioral inhibition/behavioral activation system (BIS/BAS) scales, performance indices, ERN, and Pe amplitudes. Although the ERN amplitudes did not differ between conditions, Pe amplitudes was larger in the punishment condition than in the non-punishment condition. In addition, there were moderate negative correlations between Pe amplitudes and BAS scores such that individuals with higher BAS scores exhibited smaller Pe amplitudes in general regardless of the condition. The present results suggest that the punishment of unpleasant-noise increased awareness of errors and supports the notion that the Pe may represent evaluation of error responses.

Background: Reduced motivation and blunted decision-making are key features of major depressive disorder (MDD). Patients with MDD show abnormal decision-making when given negative feedback regarding a reward. The brain mechanisms underpinning this behavior remain unclear. In the present study, we examined the association between rapid decision-making with negative feedback and brain volume in MDD.
Methods: Thirty-six patients with MDD and 54 age-, sex- and IQ-matched healthy subjects were studied. Subjects performed a rapid decision-making monetary task in which participants could make high-or low-risk choices. We compared between the 2 groups the probability that a high-risk choice followed negative feedback. In addition, we used voxel-based morphometry (VBM) to compare between group differences in gray matter volume, and the correlation between the probability for high-risk choices and brain volume.
Results: Compared to the healthy group, the MDD group showed significantly lower probabilities for high-risk choices following negative feedback. VBM analysis revealed that the MDD group had less gray matter volume in the right medial prefrontal cortex and orbitofrontal cortex (OFC) compared to the healthy group. The right OFC volume was negatively correlated with the probability that a high-risk choice followed negative feedback in patients with MDD. We did not observe these trends in healthy subjects.
Conclusions: Patients with MDD show reduced motivation for monetary incentives when they were required to make rapid decisions following negative feedback. We observed a correlation between this reduced motivation and gray matter volume in the medial and ventral prefrontal cortex, which suggests that these brain regions are likely involved in the pathophysiology of aberrant decision-making in MDD. (C) 2013 Elsevier Inc. All rights reserved.

Background: Recent studies employing stimulus-response compatibility tasks suggest that an increase in the amplitude of the positive deflection of the response-locked event-related potential (ERP) foreshadows errors on forthcoming trials. However, no studies have tested the generalizability of error-foreshadowing positivity to tasks without stimulus-response interference.
Methodology/Principal Findings: The present study adopted an alternating-response task, in which the participants responded to the pointing direction of an arrowhead (up or down). Although the arrowhead direction alternated for the majority of trials (95%), occasionally this pattern was broken by a repeated stimulus, termed a lure trial. We compared the matched-reaction-time correct-preceding ERP with the error-preceding ERP on lure-preceding trials. There was no evidence that errors are foreshadowed by the increase of a positive electroencephalogram (EEG) deflection. To the contrary, analyses of ERPs time-locked to electromyogram (EMG) onset on the five consecutive lure-preceding trials showed larger positive deflections on correct-preceding than error-preceding trials. The post-response negativity did not differ between correct-preceding and error-preceding trials.
Conclusions/Significance: These results suggest that in minimal conflict tasks a decreased positivity may foreshadow incorrect performance several trials prior to the error, possibly reflecting the waning of task-related efforts. Therefore, error-foreshadowing brain signals may be task-specific.

Objective: The present study was aimed at clarifying the effect of stimulus-response compatibility (SRC) interference on the ERN. Methods: We compared ERNs in two tasks differing in the level of interference, an arrow (AR) task classified as a Simon task and a more complex arrow-orientation (AO) task classified as a spatial-Stroop task. We also compared ERNs between partial errors (with initial incorrect movement corrected by a proper full response) and overt (uncorrected) errors. Results: Behavioral response time and error rate indicated that both interference and ERN amplitude were larger for the AO task than for the AR task. There was no significant difference in the ERN amplitude between the partial and overt errors. Conclusions: The ERN becomes larger as a function of the SRC interference. Significance: Our study presented evidence that the ERN may represent response-monitoring associated with the SRC interference. © 2011 International Federation of Clinical Neurophysiology.

Many ball sports such as tennis or baseball require precise temporal anticipation of both sensory input and motor output (i.e., receptor anticipation and effector anticipation, respectively) and close performance monitoring. We investigated the neural mechanisms underlying timing control and performance monitoring in a coincident timing task involving both types of anticipations. Peak force for two time-to-peak force (TTP) conditions-recorded with a force-sensitive key-was required to coincide with a specific position of a stimulus rotating either slow or fast on a clock face while the contingent negative variation (CNV) and the motor-elicited negativity were recorded. Absolute timing error was generally smaller for short TTP (high velocity) conditions. CNV amplitudes increased with both faster stimulus velocity and longer TTPs possibly reflecting increased motor programming efforts. In addition, the motor-elicited negativity was largest in the slow stimulus/short TTP condition, probably representing some forms of performance monitoring as well as shorter response duration. Our findings indicate that the coincident timing task is a good model for real-life situations of tool use.

Performance monitoring is an essential function involved in the correction of errors. Deterioration of this function may result in serious accidents. This function is reflected in two event-related potential (ERP) components that occur after erroneous responses, specifically the error-related negativity/error negativity (ERN/Ne) and error positivity (Pe). The ERN/Ne is thought to be associated with error detection, while the Pe is thought to reflect motivational significance or recognition of errors. Using these ERP components, some studies have shown that sleepiness resulting from extended wakefulness may cause a decline in error-monitoring function. However, the effects of sleep inertia have not yet been explored. In this study, we examined the effects of sleep inertia immediately after a 1-h daytime nap on error-monitoring function as expressed through the ERN/Ne and Pe. Nine healthy young adults participated in two different experimental conditions (nap and rest). Participants performed the arrow-orientation task before and immediately after a 1-h nap or rest period. Immediately after the nap, participants reported an increased effort to perform the task and tended to estimate their performance as better, despite no objective difference in actual performance between the two conditions. ERN/Ne amplitude showed no difference between the conditions
however, the amplitude of the Pe was reduced following the nap. These results suggest that individuals can detect their own error responses, but the motivational significance ascribed to these errors might be diminished during the sleep inertia experienced after a 1-h nap. This decline might lead to overestimation of their performance. © 2010 European Sleep Research Society.

The error (-related) negativity (Ne or ERN) has been related to detecting the mismatch between incorrectly executed and appropriate responses or, alternatively, to the degree of conflict between different response alternatives. In this study different levels of response conflict were generated by manipulating task difficulty in a Simon task. According to the product of incorrect and subsequent correct EMG activation, the amount of conflict in error trials was indeed larger for the easy than for the hard condition. In contrast, Ne/ERN amplitudes did not differ between difficulty conditions, nor was the amount of conflict mirrored by Ne/ERN amplitude. Therefore, the present data are at variance with the hypothesis that the Ne/ERN reflects the degree of response conflict.

Theories have proposed that both the stimulus-preceding negativity (SPN) and the medial frontal negativity (MFN) reflect affective/motivational processing. We examined the effect of the motivational impact of feedback stimuli on these ERPs using a simple gambling task, focusing on the influence of prior losses and gains on ERPs and choice behavior. Choices were riskier following large losses than following small losses or large gains. The MFN, however, was larger following larger gains. The SPN preceding the outcome was also larger after a greater gain. Thus, we confirmed that both the MFN and the SPN respond to the motivational properties of the feedback. A dissociation between risk-taking behavior and these ERPs suggests that there could be two monitoring systems: one that leads to riskier responses following losses and a second that leads to heightened expectancy. (c) 2006 Elsevier B.V. All rights reserved.

The behavioral, cognitive, and psychophysiological effects of extended wakefulness are well known. As time awake increases, errors become more common and are often attributed to lapses in attention. Such lapses can be reflected in the error-related negativity (Ne/ERN), a negative electroencephalogram deflection occurring after errors and is thought to be related to error detection or response conflict. Following the Ne/ERN, a positive deflection (error positivity, Pe) is also observed and is thought to reflect further evaluation of the error. To elicit Ne/ERNs, the Eriksen Flanker Task was administered to 17 women (aged 19-45 years) at two levels of alertness (4 and 20 h awake). After extended wakefulness, participants reported being subjectively sleepier and performing worse, but showed no significant difference in subjective effort. Across alertness conditions, they reported a similar number of subjective errors which closely matched an objective analysis of the errors. The Ne/ERN was not significantly reduced by sleepiness in contrast to the Pe which was reduced. Behavioral slowing after errors was larger in the alert than in the sleepy condition. These results show that after 20 h of wakefulness, individuals are reacting to their errors. However, further evaluation of the error, and remediation of these errors may be impaired despite continued effort.

The error-related negativity (ERN) is a component of the event-related brain potential (ERP) that is associated with action monitoring and error detection. The ERN amplitude reflects attentional resource allocated to error detection. The present study examined whether discrete or gradational allocation strategy of attentional resource in error detection using the ERN amplitude. Only Eriksen flanker task was used in the single task condition. Eriksen flanker task was used as a primary task and Sternberg memory search task was used as a secondary task in the dual task conditions. The task difficulty of the secondary task manipulated in the present study included the memory load. Memory set sizes of 2, 4 and 6 were used in the Sternberg memory search task (M2, M4 and M6 conditions). The results indicated that reaction time was gradually delayed in the primary task as the task difficulty of the secondary task gradually increased. However the ERN amplitude of the primary task decreased in M6 condition alone. In conclusion, discrete allocation strategy of attentional resource was adopted in the error detection.

The effect of time interval memory trace on temporal processing was investigated. Event-related potentials (ERPs) were recorded in a time reproduction task. Ten healthy participants were asked to memorize the encoding interval (3000 or 2700 ms), retain the interval during the retention period (3000 or 9000 ms) and reproduce the interval. The reproduction error of our study suggests that the reproduction of the interval was relatively difficult under encoding-2700 ms conditions. In the ERP activities at the 500-1000 ms period of the reproduction phase, the contingent negative variation (CNV) amplitude of retention-9000 ms conditions was significantly larger than that of retention-3000 ms conditions over Fpz. Our study suggests that the length of retention affects the time processing of the time reproduction, and the CNV over the frontal cortex seemed to change as a function of the remains of time interval memory trace being accompanied with attention resources allocation to efficiently execute the time reproduction task. (c) 2004 Elsevier B.V. All rights reserved.

In this study, we investigated the effect of affective valence on the stimulus-preceding negativity (SPN) using the international affective picture system (1APS). We adopted a S1-S2 paradigm, in which the subject could know the content of the forthcoming affective-slide (positive, negative or neutral picture) by the S1 cue (three types of gray-and-white striped squares). Our procedure differentiated these affective valences which were assessed by questionnaires. The self-assessment mannequin (SAM) data showed that the emotional score (pleasantness) significantly increased in the order of negative, neutral, and positive picture. The arousal scores of the SAM and the multiple mood scale (MMS) for negative picture were higher than for the other pictures. The SPN over the frontal regions significantly increased preceding the negative pictures, but not preceding the neutral and positive pictures. Our results suggest that the SPN might represent arousal induced by emotion-inducing pictures. (c) 2004 Elsevier B.V. All rights reserved.

The lateralized readiness potential (LRP) is considered to reflect motor activation and has been used extensively as a tool in elucidating cognitive processes. In the present study, we attempted to more precisely determine the origins of the LRP within the cognitive system. The response selection and motor programming stages were selectively manipulated by varying symbolic stimulus response compatibility and the time to peak force of an isometric finger extension response. Stimulus response compatibility and time to peak force affected response latency, as measured in the electromyogram, in a strictly additive fashion. The effects of the experimental manipulations on stimulus- and response-synchronized LRPs indicate that the LRP starts after the completion of response-hand selection and at the beginning of motor programming. These results allow a more rigorous interpretation of LRP findings in basic and applied research.

A growing area of research within psychophysiology concerns the error-related negativity (ERN), an eventrelated potential component that was first observed independently by the Illinois and the Dortmund groups about fifteen years ago. Since then, evidence has accumulated that the ERN represents action monitoring processes executed presumably by the anterior cingulate cortex (ACC). In this review paper, we discuss the functional significance of the processes reflected by the ERN in action monitoring. We first introduce fundamental aspects of the ERN, including its morphological characteristics, the tasks in which it has been observed, models of its neural generator, findings concerning the involvement of attention, and the relation between the ERN and the continuous vs. discrete nature of error. We discuss the ERN elicited by external feedback signals in light of its independence of motor responses and its relationship to negative affect. We focus on the error-vs. conflict-detection contro-versy, discussing recent reports addressing this issue. Because proponents of the error-detection and the conflictdetection theories have each reported convincing findings in support of their views, the controversy is not yet settled. We suggest that one reason for the difficulty in resolving the controversy is that theories and models have not specified in sufficient detail how error-detection and conflict-detection are conceptually distinct. In the final part of this paper, we introduce latest findings of the ERN and speculate on future research in this area. (Japanese Journal of Physiological Psychology and Psychophysiology, 22 (1) : 3-18, 2004.)

Error-related negativity (ERN) is observed immediately after an error in choice reaction time tasks performed by hand response. We examined whether the ERN occurs in relation to slips of vocalization in the Stroop color word task. in one condition, the subject's vocal responses were masked by continuous pink noise in order to prevent vocalization-related cortical potentials from contaminating the ERN time window. This masking procedure was successful in inhibiting the vocalization-related cortical potential. More importantly, vocalization errors elicited a frontocentral negative-going deflection followed by a positive component immediately after the error response regardless of the masking condition. The present results suggest that the error detection mechanism may also elicit an ERN-like component in response to vocal slips. NeuroReport 12:1851-1855 (C) 2001 Lippincott Williams & Wilkins.

We studied the relationship between hemispheric asymmetry, emotion, and aerobic exercise intensity. Nine participants used a bicycle ergometer to exercise for 2 15-minute periods at 2 different exercise intensities : a comfortable self-established pace (CSEP) and 70%VO₂ max. CSEP was defined as exercise intensity that the subject subjectively determined to be comfortable. Electroencephalograms (EEG) were monitored prior to exercise and during exercise recovery. To evaluate emotional changes associated with exercise, questionnaires were completed prior to, during, immediately after exercise and during exercise recovery. The α-power spectrum of the frontal EEG was classified as follows : α 1, 8-9.5 Hz; a 2, 9.5-11.5 Hz; and α 3, 11.5-13 Hz, and compared at F3 to F4 for each α-power spectrum. Both exercises at CSEP and 70%VO₂max intensity showed decreased anxiety between immediately after exercise and during exercise recovery. Duration, rise, and fall of positive emotion and relaxation differed between exercise intensities. Exercise at CSEP intensity was not hemispherically asymmetric prior to exercise and during recovery. Exercise at 70 %VO₂ max was not hemispherically asymmetric prior to exercise, however, the α 2 power of F3 was lower than that of F4 during 60-minute recovery. The left frontal α-power spectrum, specially a 2, at 70%VO₂ max would reflect increased positive emotions and decreased anxiety during exercise recovery. These results are discussed based on the approach-withdrawal model of Davidson.

This study investigated the locus of the interference effect in a stimulus-response compatibility task using event-related potentials (ERPs). Ten participants were instructed to respond to stimulus color with the left or light middle finger Red ol blue arrows pointed in the same direction as the response hand on congruent trials and pointed in the opposite direction on incongruent trials. Neutral trials were red or blue horizontal bars. Reaction times (RTs) to incongruent stimuli was significantly longer than RTs to congruent stimuli. The peak latency of the P300 for incongruent stimuli were significantly longer than that for congruent stimuli. In addition, onset of stimulus-locked lateralized readiness potential (LRPs) was significantly later for incongruent stimuli than for congruent stimuli. However, electromyogram (EMG)-locked LRPs for incongruent stimuli showed incorrect preparation. These results suggest that the interference effect might occur at the stage in which stimulus evaluation processes and response-related processes overlap.

The present study investigated the readiness potential (RP) preceding a brisk extension of the right middle finger during different arousal states as monitored by skin potential level (SPL). The late component of the readiness potential in the medium arousal state was significantly larger than those in the low and high arousal states. This finding indicates that the RP waveform may vary as a function of arousal states, suggesting the inverse U-shaped relationship proposed in studies of the contingent negative variation.

The aim of this study was to clarify the effects of bean-moving tasks on autonomic nervous activities and to confirm that these tasks are suitable for occupational therapy. We investigated three versions of bean-moving tasks, each task lasting for a period of 5 minutes. Twelve healthy participants were instructed to move beans with wooden chopsticks from one box to another in the easy task, to move them with lacquered chopsticks in the difficult task, and to perform the easy bean-moving task together with a stimulus-discrimination task in the dual-task situation. Performance was significantly lower for the difficult task compared to the other tasks. Heart rate increased during the dual task in association with the higher mental workload, motivation, and arousal. In addition, a positive skin potential response frequently occurred during the dual task, indicating a higher arousal. Based on these results, we conclude that the tasks used in this study are suitable for occupational therapy and should be performed in the order of easy, difficult, and dual-tasks to evoke different autonomic nervous activities.

Readiness potentials (RPs) preceding a trigger pulling movement were recorded in 9 right-handed male subjects. We investigated two tasks, non-purposive and purposive movement tasks. In this study we defined simple trigger pull as non-purposive, and target force production by pulling the trigger as purposive. In the non-purposive task, the subjects were instructed to pull the trigger at their own pace and at an easily-exerted force level. After two sessions in the non-purposive movement task, the subjects were submitted to the purposive movement task, and were requested to pull the trigger in an attempt to produce target force, the range of which was decided individually on the basis of mean force level in the second session of the non-purposive movement task. The RP preceding the purposive movement was larger than that preceding the non-purposive movement. In addition, enhancement of the RP was specific to the negative slope (NS'). Since neither peak force nor time to peak force of the movement differed in the two tasks, it was concluded that the increased NS' was due to a psychological change associated with execution of the purposive movement. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.