Contrast sensitivity thresholds in children with autistic spectrum disorder

Abstract

Aims: To compare a basic visual ability, contrast sensitivity, in participants with autistic spectrum disorder (ASD) and neuro-typical controls. There has been recent interest in visual perception in individuals with ASD but with the exact nature and aetiology of any abnormality yet to be defined. While some theories postulate that high-level cognitive and/or neuronal deficits underlie any perceptual abnormalities this may be premature given that very little is known about the basic integrity of the visual system in individuals with ASD. This is explored here.Methods: We used the Vector Vision CSV-1000 to measure contrast sensitivity at a range of spatial frequencies (3–18 cpd) in 30 children diagnosed with ASD and 30 typically developing controls.Results: There were no significant differences between the two groups, and all children tested showed contrast sensitivity within normal levels at all spatial frequencies.Conclusion: At a gross level visual perception is intact in ASD. Therefore, theories postulating reduced, or enhanced, contrast sensitivity are not supported as an explanation for atypical perception observed at higher levels.