Abstract
Studies investigating visual perception in Autism Spectrum Disorder (ASD) have identified atypical abilities mediated by low-, mid-, and high-levels of processing (Mottron 2006, Bertone et al 2010a). Much of this research, however, has focused on isolated levels of processing (i.e. low or high). It is therefore unknown if a functional relationship exists between levels of information processing, and moreover, if alterations in early levels of visual analysis influence mid- and high-level perception in ASD. The goal of this project was to systematically assess whether manipulating either (i) the type (luminance vs texture), or (ii) access to early, local information differentially affects performance on tasks targeting low-, mid- and high-level perceptual processes in ASD. Three separate studies examined the effects of manipulating physical stimulus properties on progressively complex visuo-spatial tasks: low-level perception was assessed using luminance- and texture-defined gratings over a range of low to high spatial frequencies; mid-level perception was examined using luminance and texture-defined radial-frequency patterns manipulated to create “bumps” along their contours to optimize global (few bumps) and local (many bumps) processing; high-level perception was assessed using a face-identification task where access to local and global cues was manipulated by presenting faces from different orientations and viewpoints. For the low-level task, results revealed an increased sensitivity of the ASD group for high-spatial frequency information in the luminance-defined condition. For the mid-level task, the ASD group performed worse than the control group for luminance-defined RFPs with few modulations, but similarly for those with many modulations. For the high-level task, individuals with ASD were significantly worse identifying faces in the view-change condition in which local cues were limited. Our findings indicate that visual abilities mediated by low-, mid- and high-level mechanisms in ASD are differentially affected by the nature and access to early visual information during task completion.
Meeting abstract presented at VSS 2015