Righi S, Marzi T, Toscani M, Baldassi S, Ottonello S, Viggiano M P
Department of Psychology, University of Florence, Italy.
Acta Psychol (Amst). 2012 Jan;139(1):7-18. doi: 10.1016/j.actpsy.2011.09.015. Epub 2011 Oct 26.
Facial expressions play a key role in affective and social behavior. However, the temporal dynamics of the brain responses to emotional faces remain still unclear, in particular an open question is at what stage of face processing expressions might influence encoding and recognition memory. To try and answer this question we recorded the event-related potentials (ERPs) elicited in an old/new recognition task. A novel aspect of the present design was that whereas faces were presented during the study phase with either a happy, fearful or neutral expression, they were always neutral during the memory retrieval task. The ERP results showed three main findings: An enhanced early fronto-central positivity for faces encoded as fearful, both during the study and the retrieval phase. During encoding subsequent memory (Dm effect) was influenced by emotion. At retrieval the early components P100 and N170 were modulated by the emotional expression of the face at the encoding phase. Finally, the later ERP components related to recognition memory were modulated by the previously encoded facial expressions. Overall, these results suggest that face recognition is modulated by top-down influences from brain areas associated with emotional memory, enhancing encoding and retrieval in particular for fearful emotional expressions.
面部表情在情感和社会行为中起着关键作用。然而，大脑对情绪面孔反应的时间动态仍不清楚，尤其是一个悬而未决的问题是，表情可能在面孔加工的哪个阶段影响编码和识别记忆。为了尝试回答这个问题，我们记录了在旧/新识别任务中诱发的事件相关电位（ERP）。本研究设计的一个新颖之处在于，虽然在学习阶段呈现的面孔带有开心、恐惧或中性表情，但在记忆检索任务中它们始终是中性的。ERP结果显示出三个主要发现：在学习和检索阶段，编码为恐惧的面孔在早期额中央部位都有增强的正电位。在编码过程中，后续记忆（Dm效应）受情绪影响。在检索时，早期成分P100和N170受编码阶段面孔情绪表达的调制。最后，与识别记忆相关的后期ERP成分受先前编码的面部表情调制。总体而言，这些结果表明，人脸识别受来自与情绪记忆相关脑区的自上而下的影响调制，特别是增强了对恐惧情绪表情的编码和检索。
