Spatio-temporal dynamics of visual processing in autism revealed by attentional masking

Autism spectrum disorder (ASD) has been associated with a detail oriented perception and an overselective attention. However, both clinical observations and experimental studies highlighted an inefficient visual selection under certain conditions. In order to understand this dissociation, we investigated the spatio-temporal dynamics of visual processing in children with ASD and IQ-matched typically developing (TD) controls, employing an Attentional Masking paradigm. Attentional Masking refers to a reduction in target identification that is followed by a second irrelevant masking object at different degrees of proximity in space and time. We found that the performance of ASD and TD group did not differ when the masking object was displayed in the same position of the target. In contrast, when the masking object appeared in lateral position in respect to the target, children with ASD showed a deeper and prolonged interference on the target identification compared to the TD group. These findings contribute to explain the dissociation between over- versus under-selectivity of visual processing in ASD, and could be interpreted in the light of the altered neural connectivity hypothesis and the reentrant theory of perception.