Mr. Grimace or Ms. Smile: does categorization affect perceptual processing in autism?

This study compared the influence of categorization on perceptual processing in adults with autistic spectrum disorders (ASD) and normal control participants. Participants were asked to categorize hybrid faces (composed of two overlapped faces of different spatial bandwidths) by gender and emotion. Control participants exhibited a bias for low-pass information during gender categorization and a bias for high-pass information during emotion categorization. By contrast, adults with ASD showed the same low-pass bias in both tasks. This absence of a shift in processing style in the ASD group is discussed in terms of diminished top-down modulation in autism.