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Sabrina Censi, Mathieu Simard, Laurent Mottron, Dave Saint-Amour, Armando Bertone; Assessing lateral interactions within the early visual areas of adults with autism.. Journal of Vision 2014;14(10):672. doi: 10.1167/14.10.672.
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© ARVO (1962-2015); The Authors (2016-present)
Background. It has been suggested that atypical visuo-spatial perception in autism may originate from altered local connectivity mediating the response properties of early visual feature detectors. The goal of this study was to assess lateral interactions between neurons within early visual areas in autism by measuring steady-state visual evoked potentials (ssVEPs) elicited by windmill-dartboard (Ratliff & Zemon, 1982) and lateral masking paradigms (Polat et al, 1997). Method. Nine participants with autism and 9 typically developing participants, matched for full-scale IQ and age (18-30 years), were asked to passively view visual stimuli during windmill-dartboard and lateral masking paradigms while ssVEPs from four electrodes over the occipital cortex (Oz, POz, O1 and O2) were collected. For the windmill-dartboard paradigm, first- and second-harmonic components of the steady-state responses were used to calculate indices reflecting facilitatory (FI) and inhibitory (SI) cortical interactions for all participants. For lateral masking paradigm, ssVEP data was collected while participants viewed Gabor patches presented either in isolation (target), or flanked by collinear Gabors at different contrasts (8, 16, 30%) at target-flanker distances (1.5λ, 3 λ, 6 λ). Results. Group differences were not evidenced for either FI or SI cortical interaction indices obtained during the windmill-dartboard task. For the lateral masking paradigm, an expected difference between collinear and orthogonal Gabors (presented at a contrast of 16%) at target-flanker distances of 1.5 λ was found in the control group, p = 0.018. Importantly, this difference was not evidenced for the autism group. Conclusion. Our results suggest that FI and SI cortical interactions within early visual brain areas are similar in autism and control groups. However, group differences on the lateral masking paradigm are consistent with the hypotheses that lateral connectivity within early visual areas is atypical in autism, and could be considered a possible early neural origin for altered perception in autism.
Meeting abstract presented at VSS 2014
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