面孔感知过程中的视觉完形负波

Visual Completion Negativity to Human Face Perception

目的探讨大脑对不完整面孔进行视觉完形加工的神经基础。方法视觉刺激分两类:完整面孔图片和不完整面孔图片(遮盖了面孔的左上象限),随机呈现,在受试者完成性别判断作业的同时记录头皮事件相关电位。结果与完整面孔相比,不完整面孔在枕颞区诱发出了明显增大的N1波,并且存在着右侧偏侧化优势;与完整面孔相比,不完整面孔诱发的N2波的峰潜伏期延长。结论增大的N1与视觉完形加工有关,视觉完形加工需要消耗时间。

Objective To explore the neural basis of visual completion for the occluded faces. Methods 2 types of visual stimuli were presented randomly： pictures of complete faces, pictures of incomplete faces （the occluded part was the left-top quadrant）. Subjects were instructed to perform a gender discrimination task while event related potentials（ERPs） were recorded. Results Com- pared with complete faces, incomplete faces enhanced the amplitude of N1 on the occipito-temporal scalp bilaterally, with the right hemisphere advantage. The peak latency of N2 elicited by incomplete faces was delayed compared with that of complete faces. Conclusion The enhancement of N1 is related to visual completion processing that requires additional time.