PERCEPTUAL AND NEURAL MECHANISMS OF THE OTHER-RACE EFFECT IN FACE RECOGNITION

The underlying cause of the other-race effect (ORE) remains controversial. A dominating social cognitive theory, suggests that group-bias causes us to process own-race and other-race faces using different cognitive processes. There are two key predictions from the social cognitive theory. Firstly, following the social categorization of faces, different cognitive processes are used to process own-race faces and other-race faces; own-race faces are individuated, whereas other-race faces are categorized. The second is that people are more engaged or attentive to own-race faces because of their in-group status. The aim of this thesis was to test these two hypotheses using behavioural and neural approaches. First, a behavioural experiment with two different tasks was developed to investigate individual differences in the ORE for face recognition. Although a clear ORE was evident, the covariation in performance across tasks suggests that similar mechanisms are involved in processing own-race and other-race faces. That is, individual performance on own-race faces correlated to other-race faces. Consistently, an item-analysis revealed that participants from different races had similar patterns of response. An analysis of the shape and texture information from the face images showed that participants used image cues in judgements similarly for own-race and other-race faces. There was also no evidence that participants spent more time on own-race compared to other-race faces. A test on face trait judgement showed participants rated on dominance and trustworthiness in similar patterns of perception for own-race and other-race faces. Finally, an fMRI study showed that own-race and other-race faces are processed in a similar way in face-selective regions of the brain. Together, the results from this thesis show that faces from different races are processed using fundamentally similar mechanisms and thus challenge key predictions from the social cognitive theory of the ORE.