Minami Tetsuto, Goto Kimiko, Kitazaki Michiteru, Nakauchi Shigeki
Intelligent Sensing System Research Center, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
Neuroreport. 2009 Oct 28;20(16):1471-6. doi: 10.1097/WNR.0b013e3283321cfb.
This study examined the relationship between the 'naturalness' of a visual stimulus and the event-related potentials measured during an oddball task. The study focused on asymmetry of the P3 amplitude during an oddball task or P3 asymmetry. Participants performed two visual oddball tasks using a pair of stimuli (A and B): one in which A was the target stimulus and B was the standard stimulus and vice versa. The stimuli consisted of natural-unnatural pairs of visual stimuli (e.g. upright-inverted faces, possible-impossible human poses). As a result of comparing the amplitudes of the target stimuli, P3 asymmetry was found in natural-unnatural pairs; that is, their naturalness differentiated the target P3 amplitude: larger P3 to the unnatural target than to the natural one. This study showed that P3 asymmetry reflected unnaturalness and unfamiliarity of visual stimuli.
本研究考察了视觉刺激的“自然度”与在Oddball任务中测量的事件相关电位之间的关系。该研究聚焦于Oddball任务期间P3波幅的不对称性，即P3不对称性。参与者使用一对刺激（A和B）执行两项视觉Oddball任务：一项任务中A是目标刺激，B是标准刺激，另一项任务中则相反。刺激由自然与非自然的视觉刺激对组成（例如正立与倒立的面孔、可能与不可能的人体姿势）。通过比较目标刺激的波幅发现，在自然与非自然刺激对中存在P3不对称性；也就是说，它们的自然度区分了目标P3波幅：非自然目标的P3波幅大于自然目标的P3波幅。本研究表明，P3不对称性反映了视觉刺激的非自然性和不熟悉性。
