面孔加工的情绪效应和效价效应

Emotional Effect and Valance Effect of Facial Processing

目的:采用面孔识别研究范式和事件相关电位方法,研究面孔加工的情绪效应。方法:14名大学生作为被试,视觉刺激包括愉快、悲伤和中性三种面孔。被试分别完成情绪—中性面孔区分和愉快—悲伤面孔区分任务。结果:①情绪—中性面孔区分任务中,在刺激出现后200～600ms出现情绪效应,情绪面孔引发的ERPs较之于中性面孔的ERPs更正。其中在200～400ms情绪效应分布在额区和中央区;在400～600ms情绪效应主要分布在顶区和中央区;②愉快—悲伤面孔区分任务中,在刺激呈现后的500～800ms出现效价效应,悲伤面孔引发的ERPs较之于愉快面孔的ERPs更正,效价效应分布在广泛的头皮位置。结论:情绪效应和效价效应可能有不同的神经机制,效价效应反映着更为精细的表情加工。

Objective： Two facial discrimination tasks were adapted to be used in an event-related potential paradigm in order to examine the late processing of facial expression. Methods： Fourteen undergraduates （7 males, 7 females） served as subjects in the experiment. Subjects were asked to complete the emotional-neutral face discrimination task and the happy-sad face discrimination task. Results： ①In the emotional-neutral face discrimination task, after the 200 and 600ms latency range, responses to emotional faces were positively related to responses of neutral faces. The emotional effect distributed at frontal and central sites between 200 and 400 ms of latency, yet at parietal and occipital sites between 400 and 600ms of latency. ②In the happy-sad face discrimination task, after the 500 and 800ms latency range, responses to sad faces were positively related to responses of happy faces, and the valance effect distributed at global scalp .sites. Conclusion： These data suggest that it is possible that emotional effect and valance effect of facial pictures rely on different neural mechanisms, and valance effect reflect more deliberate processing.