Eimer Martin, Holmes Amanda
Department of Psychology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK.
Neuropsychologia. 2007 Jan 7;45(1):15-31. doi: 10.1016/j.neuropsychologia.2006.04.022. Epub 2006 Jun 22.
Results from recent event-related brain potential (ERP) studies investigating brain processes involved in the detection and analysis of emotional facial expression are reviewed. In all experiments, emotional faces were found to trigger an increased ERP positivity relative to neutral faces. The onset of this emotional expression effect was remarkably early, ranging from 120 to 180ms post-stimulus in different experiments where faces were either presented at fixation or laterally, and with or without non-face distractor stimuli. While broadly distributed positive deflections beyond 250ms post-stimulus have been found in previous studies for non-face stimuli, the early frontocentrally distributed phase of this emotional positivity is most likely face-specific. Similar emotional expression effects were found for six basic emotions, suggesting that these effects are not primarily generated within neural structures specialised for the automatic detection of specific emotions. Expression effects were eliminated when attention was directed away from the location of peripherally presented emotional faces, indicating that they are not linked to pre-attentive emotional processing. When foveal faces were unattended, expression effects were attenuated, but not completely eliminated. It is suggested that these ERP correlates of emotional face processing reflect activity within a neocortical system where representations of emotional content are generated in a task-dependent fashion for the adaptive intentional control of behaviour. Given the early onset of the emotion-specific effects reviewed here, it is likely that this system is activated in parallel with the ongoing evaluation of emotional content in the amygdala and related subcortical brain circuits.
本文综述了近期有关事件相关脑电位（ERP）研究的结果，这些研究探讨了大脑在检测和分析情绪性面部表情时所涉及的过程。在所有实验中，相对于中性面孔，情绪性面孔均能引发ERP正波增强。这种情绪表达效应的起始非常早，在不同实验中，当面孔呈现在注视点或侧面，且有无非面孔干扰刺激时，刺激后120至180毫秒即可出现。虽然先前研究发现非面孔刺激在刺激后250毫秒以上会出现广泛分布的正波偏转，但这种情绪正波早期在前额中央分布的阶段很可能是面孔特异性的。六种基本情绪均发现了类似的情绪表达效应，这表明这些效应并非主要在专门用于自动检测特定情绪的神经结构中产生。当注意力从周边呈现的情绪性面孔位置转移时，表达效应消失，这表明它们与前注意情绪加工无关。当中央凹面孔未被注意时，表达效应减弱，但并未完全消除。研究表明，这些情绪性面孔加工的ERP相关指标反映了新皮层系统内的活动，在该系统中，情绪内容的表征以任务依赖的方式产生，用于行为的适应性有意控制。鉴于此处所综述的情绪特异性效应起始较早，该系统很可能与杏仁核及相关皮层下脑回路中正在进行的情绪内容评估同时被激活。
