面孔识别特异性脑机制的ERP研究

Specific Brain Mechanism in Face Recognition Revealed by Event-related Potentials

目的研究面孔识别加工成分N1 70是否真正反映面孔识别加工的特异性及其是否是衡量面孔结构编码的特异指标 ;另外尚运用偶极子定位法论证面孔识别加工特异脑区、面孔识别加工是否具有右半球优势等问题。方法 1 6名被试学习和再认面孔照片 ,记录其脑电。结果实验结果表明 ,仅半数被试出现N1 70 ;认知任务显著影响N1 70波幅。结论N1 70不仅反映面孔的结构编码还反映视觉直接加工等其他加工单元 ,是否反映面孔识别加工特异性还值得进一步研究 ;面孔识别加工时两半球的优势在加工速度与加工强度两个维度上各占优势 ,并非单纯的右脑优势 ,提供了支持半球间两维关系观点的新电生理学证据 ;面孔识别加工的脑区不仅限于梭状回 ,顶叶后部偏右的皮层下结构应该也是一个面孔识别加工脑区。

Objective 1) To study whether early component of face recognition——N170 reflects the speciality in face processing and reflects face structure encoding, and to demonstrate a face-specific processing area in the human brain by employing dipole source analysis. Method Event-related potentials (ERPs) were recorded in 16 normal subjects during pictures of face learning-cognition task. Result N170 was elicited by the face stimuli in only half of the subjects and the amplitude was modulated by cognitive tasks. Conclusion 1) N170 reflects not only face structure encoding unit but also direct visual processing unit. Whether N170 reflects the speciality in face recognition needs further study. 2) The latency of N170 shows left hemisphere dominance and the amplitude shows right hemisphere dominance, indicating that it is not pure right hemisphere dominance in face recognition. 3) The study validates that the face processing area in brain is right fusiform gyrus and finds that right parietal cortex is probably a face specific processing area in the human brain.