Effects of acute alcohol consumption on the perception of eye gaze direction

Alcohol consumption is associated with increases in aggressive behaviour, but the mechanisms underlying this relationship are poorly understood. One mechanism by which alcohol consumption may influence behaviour is via alterations in the processing of social cues such as gaze. We investigated the effects of acute alcohol consumption on the perception of gaze, using a task in which participants determined whether a stimulus face was looking towards or away from them. Gaze direction varied across trials, allowing calculation of a threshold at which participants considered gaze to switch from direct to averted. Target faces varied in both sex and attractiveness. Thirty social drinkers attended three randomized experimental sessions. At each session, participants consumed 0.0, 0.2 or 0.4 g/kg alcohol, and completed the gaze perception task. A significant three-way interaction involving target sex, participant sex and alcohol dose indicated that alcohol increased the cone of gaze for females viewing male targets (i.e. females were biased towards making a direct gaze judgement), but decreased the cone of gaze for males viewing male targets. Our data indicate that alcohol consumption influences gaze perception, but that these effects vary across sex of both stimulus and rater. These effects may have important implications for alcohol-related violence.