The "Mexican hat" of the attentional focus in autism spectrum disorders

Abstract

It is well established that individuals with autism spectrum disorder (ASD) manifest abnormalities in their visual perception. These abnormalities are sometimes reflected in strengths on detail-oriented tasks, but some others implicate difficulties on distractors inhibition, thus producing sensory overload. In the present study we tested whether these contradictory aspects of perceptual capacity in ASD may be due to a different spatial profile of the attentional focus. Recent neurophysiological models demonstrate that visual selection requiring spatial scrutiny for object recognition elicits – in the immediate surround of the attentional focus – a zone of attenuated excitability, evoking a spatial distribution of attentional resources that resembles a "Mexican hat". This aspect of visual attention was investigated in a group of adolescents with ASD as compared to typically developing (TD) peers matched for age and cognitive level. Our results showed that in the ASD group the attenuation surrounding the focus of attention was markedly reduced, suggesting an unbalanced relationship between neural mechanisms of enhancement and suppression at the locus of attention. Moreover, weaker suppression outside the focus of attention was correlated with higher autistic symptomatology. The present findings give a unique insight into the understanding of visual processing in autism and can help to explain the superior performance in detail-oriented tasks as well as the sensory overload often experienced by individuals with ASD.

Meeting abstract presented at VSS 2014