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Dysregulated oscillatory connectivity in the visual system in autism spectrum disorder.
Seymour, Robert A; Rippon, Gina; Gooding-Williams, Gerard; Schoffelen, Jan M; Kessler, Klaus.
Afiliação
  • Seymour RA; Aston Brain Centre, School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK.
  • Rippon G; ARC Centre of Excellence in Cognition and Its Disorders, Macquarie University, Sydney, Australia.
  • Gooding-Williams G; Department of Cognitive Science, Macquarie University, Sydney, Australia.
  • Schoffelen JM; Aston Brain Centre, School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK.
  • Kessler K; Aston Brain Centre, School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK.
Brain ; 142(10): 3294-3305, 2019 10 01.
Article em En | MEDLINE | ID: mdl-31410480
Autism spectrum disorder is increasingly associated with atypical perceptual and sensory symptoms. Here we explore the hypothesis that aberrant sensory processing in autism spectrum disorder could be linked to atypical intra- (local) and interregional (global) brain connectivity. To elucidate oscillatory dynamics and connectivity in the visual domain we used magnetoencephalography and a simple visual grating paradigm with a group of 18 adolescent autistic participants and 18 typically developing control subjects. Both groups showed similar increases in gamma (40-80 Hz) and decreases in alpha (8-13 Hz) frequency power in occipital cortex. However, systematic group differences emerged when analysing intra- and interregional connectivity in detail. First, directed connectivity was estimated using non-parametric Granger causality between visual areas V1 and V4. Feedforward V1-to-V4 connectivity, mediated by gamma oscillations, was equivalent between autism spectrum disorder and control groups, but importantly, feedback V4-to-V1 connectivity, mediated by alpha (8-13 Hz) oscillations, was significantly reduced in the autism spectrum disorder group. This reduction was positively correlated with autistic quotient scores, consistent with an atypical visual hierarchy in autism, characterized by reduced top-down modulation of visual input via alpha-band oscillations. Second, at the local level in V1, coupling of alpha-phase to gamma amplitude (alpha-gamma phase amplitude coupling) was reduced in the autism spectrum disorder group. This implies dysregulated local visual processing, with gamma oscillations decoupled from patterns of wider alpha-band phase synchrony (i.e. reduced phase amplitude coupling), possibly due to an excitation-inhibition imbalance. More generally, these results are in agreement with predictive coding accounts of neurotypical perception and indicate that visual processes in autism are less modulated by contextual feedback information.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Percepção Visual / Transtorno do Espectro Autista / Lobo Occipital Tipo de estudo: Prognostic_studies Limite: Adolescent / Female / Humans / Male Idioma: En Revista: Brain Ano de publicação: 2019 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Percepção Visual / Transtorno do Espectro Autista / Lobo Occipital Tipo de estudo: Prognostic_studies Limite: Adolescent / Female / Humans / Male Idioma: En Revista: Brain Ano de publicação: 2019 Tipo de documento: Article