Abstract
Previous work has demonstrated that two separate components of the systemizing trait of autism differentially predict susceptibility to the mechanisms that drive the Rod-and-Frame illusion, with an Analytical Tendencies factor associated with reduced reliance on global cues, and an Insistence on Sameness factor associated with increased susceptibility to local orientation contrast effects (Reed & Dassonville, VSS 2012). However, it is unclear whether these associations reflect atypical contextual modulation only at higher levels of processing, or whether low-level visual processes (i.e., in primary visual cortex) may also be affected. To examine this, we compared scores on the Systemizing Quotient-Revised (Wheelwright et al., 2006) in the general population to individual differences in the contextual modulation of perceived orientation induced by lateral and collinear flankers, presented at the estimated size of V1 receptive fields. When an observer judges the orientation of a central line in the presence of lateral flankers, the perceived orientation of the line is biased in the direction opposite the tilt of the flankers (a repulsive effect), while the same judgments made in the presence of collinear flankers bias the perceived orientation of the line in the same direction as the flankers (an attractive effect). We found that higher scores on the Analytical Tendencies factor of the SQ-R were associated with reduced contextual effects of collinear flankers, but were unrelated to contextual interactions induced by lateral flankers. Conversely, higher scores on the Insistence on Sameness factor were associated with increased contextual effects of lateral flankers, but were unrelated to contextual effects induced by collinear flankers. These findings suggest that distinct systemizing tendencies differentially predict low-level contextual interactions that are thought to occur in primary visual cortex, and provide insight to the relationship between the functional structure of V1 and the behavioral tendencies associated with autism.
Meeting abstract presented at VSS 2015