A specific autistic trait that modulates visuospatial illusion susceptibility.

Although several accounts of autism have predicted that the disorder should be associated with a decreased susceptibility to visual illusions, previous experimental results have been mixed. This study examined whether a link between autism and illusion susceptibility can be more convincingly demonstrated by assessing the relationships between susceptibility and the extent to which several individual autistic traits are exhibited as a continuum in a population of college students. A significant relationship was observed between the systemizing trait and susceptibility to a subset of the tested illusions (the rod-and-frame, Roelofs, Ponzo and Poggendorff illusions). These results provide support for the idea that autism involves an imbalance between the processing of local and global cues, more heavily weighted toward local features than in the typically developed individual.