Event-related potentials as neurophysiological markers of face perception and face recognition

The perception and recognition of faces are complex brain functions of great psychobiological relevance and have been studied by the neuroscientific community for decades. This paper reviews existing data on event-related potentials and facial processing, therefore, the functional significance of each psychophysiological response, in relation with the different stages or modules described in cognitive and neural models regarding the processing of familiar and unknown faces are discussed. The initial processing of faces is related to early electrophysiological responses as occipital P120 wave, associated with the detection of primary structural features suggestive of, basically, the presence of a face in our visual field. The posterior temporal N170 wave is more sensitive to facial configuration (vs. other objects) and to the presence of specific facial features before the intra-categorical identification takes place (visual recognition of identity), while the later latency responses as the anterior temporal N250r and the more topographically distributed N400 are those that reflect, respectively, the access and retrieval of information on familiar faces in long-term memory.