Interaction of threat expressions and eye gaze: an event-related potential study.

The current study examined the interaction of fearful, angry, happy, and neutral expressions with left, straight, and right eye gaze directions. Human participants viewed faces consisting of various expression and eye gaze combinations while event-related potential (ERP) data were collected. The results showed that angry expressions modulated the mean amplitude of the P1, whereas fearful and happy expressions modulated the mean amplitude of the N170. No influence of eye gaze on mean amplitudes for the P1 and N170 emerged. Fearful, angry, and happy expressions began to interact with eye gaze to influence mean amplitudes in the time window of 200-400 ms. The results suggest early processing of expression influence ERPs independent of eye gaze, whereas expression and gaze interact to influence later ERPs.