The Processing of Fearful Gaze Cue : A Developmental Cognitive Neuroscience Study

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 開 一夫, 東京大学教授 植田 一博, 東京大学教授 横山 ゆりか, 東京大学教授 長谷川 壽一, 東京大学教授 岡ノ谷 一夫University of Tokyo(東京大学

Rapid saccadic response with fearful gaze cue.

It has been shown that an averted gaze with emotional expression guides our attention toward a gazed-at location, and the effect of a gaze with fearful expression has been well-investigated. However, the findings are not consistent, and most studies used the manual response measure. Recent studies suggest that examining eye movements is more suitable to capture the early stage of the effect of threat-related stimuli on attentional process. Therefore, in the present study, we investigated the effects of static neutral and fearful gaze on overt attention orienting by examining the saccadic responses in an unselected sample of people. Our results found the gaze congruency effects for both expressions, and importantly, enhanced attention orienting by fearful gaze at a short stimulus onset asynchrony (SOA): participants looked faster at the fearful gaze-cued target than the neutral gaze-cued one at the 300 ms SOA. These findings provide the first evidence that fearful averted gaze elicits rapid overt attention orienting toward the target, and suggest that the information of gaze direction and emotional expression are rapidly integrated and modulate the oculomotor system

Mean Scores of Analysed Variables for Each Condition in Experiment 2.

<p><i>Note</i>. Values in parentheses are standard deviations.</p

Example of a stimulus presentation sequence.

<p>The expression is fearful; the target appears on the incongruent side. At the beginning of each trial, an attractor stimulus was presented on the monitor until the infant fixated on the object. Then a face with a leftward or rightward gaze direction showing a neutral or fearful expression was presented for 1000 ms. The monitor then displayed a blank screen for 200 ms, followed by the presentation of a leftward or rightward peripheral target for 1500 ms. Another blank screen was then presented for 800 ms, and the next trial started. The images of faces shown here do not depict the actual stimuli, but are intended only as examples.</p

Mean Scores of Analysed Variables for Each Condition in 6- and 12-month-olds in Experiment 1.

<p><i>Note</i>. Values in parentheses are standard deviations.</p

Mean saccadic reaction times (SRTs) for gaze direction conditions among neutral and fearful expressions.

<p>SRTs for leftward, rightward, and forward gaze direction conditions for neutral and fearful expressions in Experiment 2 are shown. Error bars indicate standard errors of the mean.</p