Rapid reactions to direct and averted facial expressions of fear and anger

Recent studies have shown that reaction times to expressions of anger with averted gaze and fear with direct gaze appear slower than those to direct anger and averted fear. Such findings have been explained by appealing to the notion of gaze/expression congruence with aversion (avoidance) associated with fear, whereas directness (approach) is associated with anger. The current study examined reactions to briefly presented direct and averted faces displaying expressions of fear and anger. Participants were shown four blocked series of faces; each block contained an equal mix of two facial expressions (neutral plus either fear or anger) presented at one viewpoint (either full face or three quarter leftward facing). Participants were instructed to make rapid responses classifying the expressions as either neutral or expressive. Initial analysis of reaction time distributions showed differences in distribution shape with reactions to averted anger and direct fear showing greater skew than those to direct anger and averted fear. Computational modelling, using a diffusion model of decision making and reaction time, showed a difference in the rate of information accrual with more rapid rates of accrual when viewpoint and expression were congruent. This analysis supports the notion of signal congruence as a mechanism through which gaze and viewpoint affect our responses to facial expressions.