[Visual evoked potentials and face recognition. Influence of celebrity and emotional expression]

Visual evoked potentials (VEP) were recorded in the right and left parietal and occipital regions of 40 right-handed controls in a facial recognition task. VEP were studied first according to the renown of the faces, then according to their emotional expression. Asymmetry was noted between the hemispheres: P100 was of greater amplitude and longer latency in the left occipital region. Later components (P400 and P600) were of greater amplitude and longer latency in the right parietal region in all situations. P100 latency on the left side was shorter for renowned faces than for non-renowned faces (P = 0.05). P600 latency was shorter on the right (P < 0.03) and left (P < 0.05) sides for smiling than for non-smiling faces. When the subjects were asked to look for emotional expression of the face (smiling or non-smiling) P400 was very ample and P600 of little amplitude. When the subjects were asked to recognize the face (renowned or not renowned) P600 was very ample and P400 of little amplitude. Thus, there seems to be a differential treatment of information: automatic and rapid to detect emotion (P400), controlled, tardy (P600) and involving memory in the search for renown.