Unconscious processing of direct gaze: evidence from an ERP study

Humans detect faces with direct gaze more rapidly than they do faces with averted gaze. Evidence suggests that the visual information of faces with direct gaze reaches conscious awareness faster than that of faces with averted gaze. This suggests that faces with direct gaze are effectively processed in the brain before they reach conscious awareness; however, it is unclear how the unconscious perception of faces with direct gaze is processed in the brain. To address this unanswered question, we recorded event-related potentials while observers viewed faces with direct or averted gaze that were either visible or rendered invisible during continuous flash suppression. We observed that invisible faces with direct gaze elicited significantly larger negative deflections than did invisible faces with averted gaze at 200, 250, and 350 ms over the parietofrontal electrodes, whereas we did not observe such effects when facial images were visible. Our results suggest that the visual information of faces with direct gaze is preferentially processed in the brain when they are presented unconsciously.