Preserved low-level visual gain control in autistic adults

Background: No sensory stimulus is an island entire of itself, the processing of visual inputs is highly influenced by surrounding spatial context. Some accounts of Autism Spectrum Disorder have suggested that the sensory difficulties reported in the condition could arise from differences in contextual modulation of sensory stimuli, specifically problems with gain control mechanisms that regulate incoming sensory information as a function of sensory context. Methods: Here we examined the spatial modulation of visual processing in autistic and neurotypical adults by assessing surround suppression for two low-level visual features: orientation and luminance. We used an established psychophysical task with known neurocomputational correlates and interrogated group differences in suppression magnitude. Results: We found that the magnitude of surround suppression for both visual features was equivalent in autistic adults and matched neurotypical controls. Additionally, there was no relationship between suppression magnitude and autism symptom severity. Conclusion: These results suggest that for low level visual features, the spatial gain control mechanisms regulating sensory input are preserved. These findings have important theoretical implications for establishing the types of gain control mechanisms that are compromised in autism, and the extent to which there are differences in contextual processing.