Interaction of gaze direction and facial expressions processing: ERP study.

Event related potentials (ERPs) were recorded from 11 subjects watching photographs of angry and happy faces with different gaze directions. ERPs to right averted gaze differed from those to straight and left averted gaze at 85 and 460 ms whereas ERPs to happy and angry expressions differed at 115, 330 and 380 ms. We suggest that short-latency effects, maximal over occipital cortex, reflect the involvement of visual cortex in the early analysis of socially-relevant stimuli. Interaction of gaze and expressions was reflected in ERPs at 270 - 450 ms. We conclude that gaze and emotional expressions are analyzed in parallel at the early stages of visual processing. The interaction of these two processing streams starts no earlier than at 270 ms.