Event-related potentials to emotional and neutral stimuli.

The present study examined subjects' cognitive processing of pictures of emotional and neutral facial expressions, as measured by Event-Related Potentials (ERPs). In Experiment 1, 10 subjects viewed two slides of a woman modelling angry and happy expressions; in Experiment 2, 10 subjects viewed slides of two women modelling neutral expressions. One face appeared on 20% of the trials and the other on 80% of the trials. Subjects counted the low frequency target face. In both experiments, the area of the P300 component was larger at Pz than Cz. In Experiment 1, P300 area was larger when the target was happy; peak amplitude was greater when the target was angry. No differences between neutral target faces were found for P300 amplitude or area in Experiment 2. These results suggest that emotional versus neutral facial expressions elicit different electrophysiological responses; responses are further differentiated to positive versus negative expressions.