Abstract
It has been suggested that a core feature of the autism spectrum disorders (ASD) is a profound inability to integrate the contextual elements of a perceptual scene (“weak central coherence,” Frith 1989). While this theory suggests that a contextual processing deficit causes many of the impairments associated with ASD, it could also explain the enhanced performance on some visuospatial tasks, such as the Hidden Figures Task (HFT; Happe 1999). The theory also predicts that individuals with ASD should be less susceptible to visual illusions, as they should not naturally integrate the misleading contextual elements that cause the illusions. Unfortunately, experimental evidence of a decreased susceptibility to illusions in ASD is spotty at best (see Happe 1996; Ropar & Mitchell 2000, 2001). However, these previous studies may have suffered from confounds associated with the diverse spectrum of traits exhibited by individuals with ASD, and with differences in illusion susceptibility associated with chronological-age (children with ASD were matched with controls of a similar mental-age). Here, we examined the relationship between illusion susceptibility and specific autistic traits, as exhibited (in varying degrees) within a population of healthy college students. Using a factor analysis to find underlying patterns in the data from 301 participants, we found that illusion susceptibility was negatively correlated to the autistic trait of systemizing as measured by the Systemizing Quotient (SQ, Baron-Cohen et al. 2003) while performance in HFT and intuitive physics (Baron-Cohen et al. 2001) were positively correlated with SQ. In contrast, performance in these tasks was not related to scores on the Empathizing Quotient or the more general Autism Quotient (EQ, AQ; Baron-Cohen et al. 2004, 2001). Thus, although ASD is associated with enhanced performance on visuospatial tasks, the degree of enhancement is most directly modulated by the extent to which an individual exhibits the systemizing trait