Abstract
Autism Spectrum Disorder (ASD) is often associated with impaired performance in high-level visual tasks such as recognition of faces or facial expressions. In contrast, individuals with ASD may outperform neurotypical controls in detail-oriented visual tasks. We investigated whether this superior ability for fine detail in ASD originates from fundamentally superior low-level processing of spatial frequency and orientation. We tested 19 adult participants, 13 controls and 6 with ASD in two low-level and three high-level visual tasks. In Experiment 1, we measured contrast thresholds for detecting Gabor patches ranging in spatial frequency between 0.5-16cpd. Control results replicated typical contrast sensitivity profiles. ASD participants either showed atypical and reduced contrast sensitivity compared to controls (N=4), or showed typical profiles with higher sensitivity than controls at high spatial frequencies (N=2). In Experiment 2, we measured orientation discrimination thresholds for a 4cpd Gabor patch across base orientations ranging between 0-180 degrees. Controls again yielded typical curves associated with the oblique effect showing better discrimination around vertical and horizontal compared to oblique angles. Alternatively, ASD participants either showed a flat elevated threshold profile (N=3) or an impaired oblique effect (N=3). In Experiment 3, we measured contrast thresholds for face and house recognition. ASD participants were impaired in both tasks compared to controls. Moreover, the ASD group performed better with houses than faces whereas controls showed an opposite trend. Finally, in Experiment 4, we measured discrimination thresholds for subtle changes in facial expression. ASD participants showed significantly impaired performance compared to controls. Overall, our results confirm that high-level visual ability is impacted in people with ASD. In addition, these results suggest significant variation in visual abilities across the ASD population. While some may be impaired in both low and high-level tasks, others may show typical or superior low-level vision despite higher-level impairments.
Meeting abstract presented at VSS 2013