<p>The authors examined the effects of chair swiveling with the psycho-physiological effects of viewing short segments of 360° videos using a head-mounted display (HMD) in terms of the type of content. Twenty participants viewed 360° videos with varying features using an eye-tracking HMD consisting of a smartphone fitted in a case containing optics. Ten participants were seated on a swivel chair and the others on a fixed one. Objective indexes on gaze and body rotation and subjective indexes on simulator sickness, emotional reaction and immersion were measured. It was found that the features of content, especially camera motion, affect psychological effects like discomfort and observation behavior, and chair swiveling affects the behavior looking around, the reception of visual information and emotional response. It turns out that the rotating chair, which is easy to think that it supports the action the user sees, does not necessarily contribute to the user experience.</p>

<p>本研究ではスマートフォンを用いた簡易型ヘッドマウントディスプレイ（HMD）による立体視（3D）コンテンツの観察において，画面サイズの変化がユーザ体験に及ぼす影響とその補正方法について，実験的な検討を行った．具体的には，簡易型HMDを用いて3Dコンテンツの呈示サイズを変化させた際のユーザ体験として，立体感，自然さ，臨場感，見やすさ，視覚負担の5項目について7件法で回答を求めた．呈示サイズと水平方向のシフトによる補正の有無を要因とした検討の結果，呈示サイズがユーザ体験に影響し，補正によりその影響が軽減されることが確認された．</p>

<p>The authors examined the psycho-physiological effects of viewing short segments of 360° videos using a head-mounted display (HMD) in terms of the type of content and the viewing environment. Twenty participants viewed 360° videos with varying features using an eye-tracking HMD consisting of a smartphone fitted in a case containing optics. Ten participants were seated on a swivel chair and the others on a fixed one. As objective indexes, changes in the direction of gaze and body rotation (shoulder and head) were measured during viewing. As subjective indexes, motion sickness, emotional reaction and presence and immersion were measured. The results of the objective indexes showed that gaze tended to focus on the center of the screen when there was more camera motion. Further, chair swiveling increased head motion and horizontal eye movement. Results of the subjective indexes showed that the content type affected subjective symptoms of sickness and emotional arousal. Furthermore, chair swiveling augmented these symptoms and decreased the arousal level. In conclusion, it is suggested that the behavioral and psychological responses of viewing short segments of 360° videos using an HMD are affected by both the characteristics of the content being viewed and the viewing environment.</p>

<p>In this study, the authors examined behavioral characteristics during viewing 360-degree (360) images by measuring time-series change of body part rotations. In the experiment, two conditions were prepared. First was the HMD condition which a simple head-mounted display using a smartphone was used, and second was the LCD condition which a LC display with similar viewing angle was used. Four types of still images with different number of gaze targets were presented as the experimental stimuli. Under the two experimental conditions, body part rotations of the participants and subjective indexes on motion sickness and visual fatigue were measured and analyzed. From the results of the experiment, the authors found a common tendency of the late and peak in the time series rotation of body parts. The authors discussed further results of the experiment in terms of the basic tendencies of behavioral changes by viewing 360 images.</p>