[Human visual evoked potentials during the recognition of facial emotional expression]

Visual evoked potentials (VEPs) were recorded in 22 right-handed healthy subjects in the occipital, parietal, central, frontal and posterotemporal cortical areas during recognition and passive viewing of positive, negative, and neutral emotional facial expression. Peak latencies of N90, P150, and N180 VEP components appeared to be significantly shorter in response to the negative emotional expression than during administration of other facial stimuli. The differences were observed both during active recognition and passive viewing. Correct recognition was characterized by involvement of both hemispheres and high level of interhemispheric correlation between the peak latencies of P150 in the posterotemporal and of N180 in the frontal areas. It is suggested that the facial expressions are primarily recognized at the subthreshold level with participation of the posterotemporal areas. The role of the frontal areas is discussed in the completion of this process and making the correct decision about the image.