自我旋转面孔识别的ERPs研究

本研究采用事件相关电位技术考察平面旋转角度对自我面孔识别影响的时间进程。实验采用面孔异同匹配范式(same-different judgment), 首先呈现一张正立的自我或他人内特征的探测面孔, 然后再呈现一张旋转至某个角度(0°、90°、180°)的自我或他人的目标面孔, 要求被试判断两张面孔是否属于同一个人, 并记录其判断的反应时和ERP成分。实验发现, 在N170 (180~240 ms)和N2 (240~300 ms)成分上, 旋转至90°、180°的面孔刺激比正立条件下的面孔刺激分别在枕颞叶和额区诱发了更大的平均波幅。在LPP (400~500 ms)成分上, 对于自我面孔, 正立条件、旋转至90°、旋转至180°所诱发的波幅差异显著。而对于他人面孔, 3个角度所诱发的波幅无显著差异。结果表明, 面孔识别早期阶段是自动化的结构编码, 旋转角度增加了面孔结构编码的难度; 在面孔识别晚期阶段, 大脑对面孔的特异性信息进行精细加工, 自我面孔会占用个体有限认知资源进行下一步精细的心理旋转加工, 因此平面旋转角度会调节晚期个体对自我面孔的加工过程, 并且其影响时间约为100 ms。

Rotated self-face recognition: Evidence from ERPs

Previous studies showed that the angles of rotation could influence the face recognition. And the “self-face advantage”, refers to individuals respond to self-face faster than other’s face and self-face induce larger amplitudes than other’s face, is an important content in face recognition. And how picture plane rotation angles influence “self-face advantage”, and how the rotated self-face recognition performs in brain is unclear. In the present study, we adopted the Event related potential technology to investigate the temporal processing of the influence of picture plane rotation angles on “self-face advantage”. The study was a 2 (Face type: self-face VS face of other ) × 2 (Angles of rotation: 0°, 90°, 180°) within groups design. We used the same- different face-matching judgment task, 20 participants were asked to judge whether or not two successive faces represented the same person: The first face (the probe stimulus) was the participant’s self-face or an acquaintance’s face presented upright, and the second face (the target stimulus) was a self-face or an acquaintance’s face which was rotated to a certain angle (0°, 90°, 180°), and the response times and the components of ERPs were recorded. The results of ERP showed that there was a main effect of angles of rotation, and the target stimulus elicited larger N170 (180~240 ms) amplitudes under rotated to 90°, 180° than rotated to 0° condition in occipito-temporal area. And there was a main effect of angles of rotation, and the target stimulus elicited larger N2 (240~300 ms) amplitudes under rotated to 90°, 180° than rotated to 0° condition. And for the component of LPP (400~500 ms),there was a significant interaction between Face type and Angles of rotation. Furthermore, for self-face, there was a significant difference among 0°, 90° and 180°. However, for other’s face, there was no significant difference among three conditions. Our results indicate human brains decoded the facial configurational information automatically in earlier stage. In the later stage, individual will process facial identify information elaborately, and self-face can occupy the limited cognitive resource to operate the mental rotation. Thus, the self-face advantage can be regulated by the angles of rotation in the picture plane.