面孔内外特征对东西方面孔识别影响的ERP研究

目的 研究有无外部特征的东西方面孔在认知识别上的脑机制。方法 16名被试者辨别东西方人面孔性别，记录其脑电。结果 无论东西方面孔，无外部特征比有外部特征的面孔的P170波幅均增大，而N240波幅明显减小；西方面孔无外部特征与有外部特征的面孔产生的P170和N240之间的差异较东方面孔的小。上述变化在头皮前部更为显著。结论 在识别东西方面孔的过程中，均需要更多的资源分配于无外部特征面孔；有外部特征的面孔在加工机制上明显不同于没有外部特征的面孔，这一点还表现为被试者正确率的增加和反应时的加快；另外，西方面孔产生的差异波较东方面孔的小为弄族面孔在识别上容易混淆提供了电生理证据，而且也为弄族效应理论中的种族特征没有包含在面孔外部特征上提供了电生理证据。

Recognition of Eastern and Western Faces with Internal and External Features: An ERP Study

Objective To study the differences between recognitions of eastern and western faces with internal and external features (IF and EF). Method Event related potentials (ERPs) were recorded in 16 healthy subjects during gender discrimination task. Result Whether the faces were eastern or western, the faces without EF produced a larger P 170 and a smaller N 240 than the faces with EF. The difference between P 170 and N 240 elicited by western faces with or without EF was smaller than that of eastern faces, and it was more remarkable on foreside of the scalp. Conclusion Whether the face was eastern or western, more resources were distributed to faces without EF in recognition process. The processing mechanism for faces without EF was different from faces with EF and its processing depth was larger. The difference between the waves elicited by western faces was smaller than that elicited by eastern faces, which provided an evidence that western faces are easier to be confused. Moreover, no N 170 was found in the experiment, whether the face had EF or not.N 170 is probably related to structural characters of the faces or face prototype in the brain.