Does gaze direction of fearful faces facilitate the processing of threat? An ERP study of spatial precuing effects.

Eye gaze is very important for attentional orienting in social life. By adopting the event-related potential (ERP) technique, we explored whether attentional orienting of eye gaze is modulated by emotional congruency between facial expressions and the targets in a spatial cuing task. Faces with different emotional expressions (fearful/angry/happy/neutral) directing their eye gaze to the left or right were used as cues, indicating the possible location of subsequent targets. Targets were line drawings of animals, which could be either threatening or neutral. Participants indicated by choice responses whether the animal would fit inside a shoebox in real life or not. Reaction times to targets were faster after valid compared with invalid cues, showing the typical eye gaze cuing effect. Analyses of the late positive potential (LPP) elicited by targets revealed a significant modulation of the gaze cuing effect by emotional congruency. Threatening targets elicited larger LPPs when validly cued by gaze in faces with negative (fearful and angry) expressions. Similarly, neutral targets showed larger LPPs when validly cued by faces with neutral expressions. Such effects were not present after happy face cues. Source localization in the LPP time window revealed that for threatening targets, the activity of right medial frontal gyrus could be related to a larger gaze-orienting effect for the fearful than the angry condition. Our findings provide electrophysiological evidence for the modulation of gaze cuing effects by emotional congruency.