Hinojosa J A, Mercado F, Carretié L
Instituto Pluridisciplinar, Universidad Complutense de Madrid, Madrid, Spain; Facultad de Psicología, Universidad Complutense de Madrid, Madrid, Spain.
Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Madrid, Spain.
Neurosci Biobehav Rev. 2015 Aug;55:498-509. doi: 10.1016/j.neubiorev.2015.06.002. Epub 2015 Jun 9.
The N170 component is the most important electrophysiological index of face processing. Early studies concluded that it was insensitive to facial expression, thus supporting dual theories postulating separate mechanisms for identity and expression encoding. However, recent evidence contradicts this assumption. We conducted a meta-analysis to resolve inconsistencies and to derive theoretical implications. A systematic revision of 128 studies analyzing N170 in response to neutral and emotional expressions yielded 57 meta-analyzable experiments (involving 1645 healthy adults). First, the N170 was found to be sensitive to facial expressions, supporting proposals arguing for integrated rather than segregated mechanisms in the processing of identity and expression. Second, this sensitivity is heterogeneous, with anger, fear and happy faces eliciting the largest N170 amplitudes. Third, we explored some modulatory factors, including the focus of attention - N170 amplitude was found to be also sensitive to unattended expressions - or the reference electrode -common reference reinforcing the effects- . In sum, N170 is a valuable tool to study the neural processing of facial expressions in order to develop current theories.
N170成分是面部加工最重要的电生理指标。早期研究得出结论，它对面部表情不敏感，从而支持了假设身份和表情编码存在独立机制的二元理论。然而，最近的证据与这一假设相矛盾。我们进行了一项荟萃分析，以解决不一致之处并得出理论启示。对128项分析N170对中性和情感表情反应的研究进行系统修订，得到了57个可进行荟萃分析的实验（涉及1645名健康成年人）。首先，发现N170对面部表情敏感，支持了主张在身份和表情加工中采用整合而非分离机制的观点。其次，这种敏感性是异质性的，愤怒、恐惧和快乐表情引发的N170波幅最大。第三，我们探究了一些调节因素，包括注意力焦点——发现N170波幅对未被注意的表情也敏感——或参考电极——共同参考增强了效应。总之，N170是研究面部表情神经加工以完善当前理论的宝贵工具。
