Facial Expression And Gaze-direction In Face Perception

Eyes are central to various aspects of face processing, including face perception,gender discrimination, identity recognition and facial expression discrimination, and facialexpression and gaze-direction are two important dynamic aspects of human faces.Expressions communicate the internal emotional state of others while gaze-direction offerscues to their attentional focus and future intentions.Here we explored the relationship between the processing of facial expression and theprocessing of gaze-direction. In the current study24subjects were instructed to judge thegaze-direction (direct or averted gaze) or expression (happy or fear) of presented faceswhile we recorded reaction time and brain potentials with event-related potential(ERP)technique.Behavioral results confirmed the prediction that gaze-direction facilitated theprocessing of facially emotional expressions (both fear and happy), however, emotionalexpression had no reciprocal influence on judgment of gaze-direction. Data of ERPsrevealed that amplitudes elicited by fearful faces were larger than those elicited by happyfrom very early stage even from about100ms, consistent with the presence of a ‘negativitybias’. Even we found that direct gaze faces were recognized faster than averted-gaze faces,but this effect of direct gaze had little demonstration in brain potentials. The brain waves ofgaze and emotional expressions are integrated at the early stages of visual processing, andthese two processing streams were dissociable at no earlier than300ms. The late positivecomponent of emotional processing appeared earlier than that of gaze-direction processing,consistent with the behavioral results that RTs for expression judgements were faster thangaze-direction judgements.