Abstract
Individuals with autism spectrum disorders (ASD) have impairments in face recognition tasks. It has been suggested that this impairment occurs in part because, in contrast to typically developed individuals, individuals with ASD do not spontaneously make use of the eyes region of the face. Indeed, some researchers have suggested that individuals with ASD attend preferentially to the mouth. To test this hypothesis, we adapted Barton et al.'s (2001) feature displacement discrimination task for 16 high-functioning adult males with ASD and 19 sex- and IQ-matched controls. Like Barton and colleagues, for typically developed individuals, we found relatively low displacement thresholds for both eye and mouth discriminations when stimuli were upright. When stimuli were inverted, thresholds remained low for eye discriminations, but were significantly elevated for mouth discriminations, consistent with the interpretation that typically developed observers give priority to processing eyes (e.g., Sekuler et al., 2004). If individuals with ASD prioritize the mouth over the eyes, one would expect the reverse pattern of results (low thresholds in both orientations for mouth discriminations, and low thresholds only when upright for eye discriminations). In contrast to this prediction, we found no inversion effect for individuals with ASD when viewing eyes, but overall performance was significantly impaired relative to controls. Performance on discriminations of mouth displacements did not differ significantly across groups. As such, our results are consistent with the view that a deficit exists in processing eyes in ASD, but the mouth does not appear to receive processing priority.
Natural Sciences and Engineering Research Council of Canada, and the Canada Research Chairs program