Prolonged neural encoding of visual information in autism

Abstract

Autism spectrum disorder (ASD) is associated with a hyper‐focused visual attentional style, impacting higher‐order social and affective domains. The understanding of such peculiarity can benefit from the use of multivariate pattern analysis (MVPA) of high‐resolution electroencephalography (EEG) data, which has proved to be a powerful technique to investigate the hidden neural dynamics orchestrating sensory and cognitive processes. Here, we recorded EEG in typically developing (TD) children and in children with ASD during a visuo‐spatial attentional task where attention was exogenously captured by a small (zoom‐in) or large (zoom‐out) cue in the visual field before the appearance of a target at different eccentricities. MVPA was performed both in the cue‐locked period, to reveal potential differences in the modulation of the attentional focus, and in the target‐locked period, to reveal potential cascade effects on stimulus processing. Cue‐locked MVPA revealed that while in the TD group the pattern of neural activity contained information about the cue mainly before the target appearance, the ASD group showed a temporally sustained and topographically diffuse significant decoding of the cue neural response even after the target onset, suggesting a delayed extinction of cue‐related neural activity. Crucially, this delayed extinction positively correlated with behavioral measures of attentional hyperfocusing. Results of target‐locked MVPA were coherent with a hyper‐focused attentional profile, highlighting an earlier and stronger decoding of target neural responses in small cue trials in the ASD group. The present findings document a spatially and temporally overrepresented encoding of visual information in ASD, which can constitute one of the main reasons behind their peculiar cognitive style.