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Visual Magnocellular Function in Perceptual Disorders

Developmental disorders such as autism spectrum disorders (ASD), dyslexia, schizophrenia and dyscalculia have also been reported to show abnormal visual perception. Central to the four disorders are observations of altered global/local perception, motion sensation and grouping that are suggestive of...

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Autores principales: Crewther, David P., Laycock, Robin, Jastrzebski, Nikki, Crewther, Daniel P., Crewther, Sheila G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: SAGE Publications 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5393755/
http://dx.doi.org/10.1068/ic416
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author Crewther, David P.
Laycock, Robin
Jastrzebski, Nikki
Crewther, Daniel P.
Crewther, Sheila G.
author_facet Crewther, David P.
Laycock, Robin
Jastrzebski, Nikki
Crewther, Daniel P.
Crewther, Sheila G.
author_sort Crewther, David P.
collection PubMed
description Developmental disorders such as autism spectrum disorders (ASD), dyslexia, schizophrenia and dyscalculia have also been reported to show abnormal visual perception. Central to the four disorders are observations of altered global/local perception, motion sensation and grouping that are suggestive of a magnocellular abnormality(s). Such psychophysical observations do not easily yield neurophysiological mechanisms that can explain the altered perception/vision. Nonlinear visual evoked potentials have allowed the separation of magnocellular (M) and parvocellular (P) contributions to the VEP (Klistorner et al., 1997). Using these tools we compare the patterns of abnormality in groups with visual disorders. The second order kernel responses of the VEP in autistic tendency show interference between P and M nonlinearities at high contrast (Sutherland & Crewther, 2010) resulting in a delay of completion of firing. While afferent latencies of M and P cortical activation are not different in ASD, the delay in completion may allow a revision of the ideas surrounding the “magnocellular advantage” which relate to the alterations observed in global and local perception.
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spelling pubmed-53937552017-04-24 Visual Magnocellular Function in Perceptual Disorders Crewther, David P. Laycock, Robin Jastrzebski, Nikki Crewther, Daniel P. Crewther, Sheila G. Iperception Article Developmental disorders such as autism spectrum disorders (ASD), dyslexia, schizophrenia and dyscalculia have also been reported to show abnormal visual perception. Central to the four disorders are observations of altered global/local perception, motion sensation and grouping that are suggestive of a magnocellular abnormality(s). Such psychophysical observations do not easily yield neurophysiological mechanisms that can explain the altered perception/vision. Nonlinear visual evoked potentials have allowed the separation of magnocellular (M) and parvocellular (P) contributions to the VEP (Klistorner et al., 1997). Using these tools we compare the patterns of abnormality in groups with visual disorders. The second order kernel responses of the VEP in autistic tendency show interference between P and M nonlinearities at high contrast (Sutherland & Crewther, 2010) resulting in a delay of completion of firing. While afferent latencies of M and P cortical activation are not different in ASD, the delay in completion may allow a revision of the ideas surrounding the “magnocellular advantage” which relate to the alterations observed in global and local perception. SAGE Publications 2011-05-01 2011-05 /pmc/articles/PMC5393755/ http://dx.doi.org/10.1068/ic416 Text en © 2011 SAGE Publications Ltd. Manuscript content on this site is licensed under Creative Commons Licenses http://creativecommons.org/licenses/by-nc-nd/3.0/ This article is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License (http://www.creativecommons.org/licenses/by-nc-nd/3.0/) which permits non-commercial use, reproduction and distribution of the work as published without adaptation or alteration, without further permission provided the original work is attributed as specified on the SAGE and Open Access page (http://www.uk.sagepub.com/aboutus/openaccess.htm).
spellingShingle Article
Crewther, David P.
Laycock, Robin
Jastrzebski, Nikki
Crewther, Daniel P.
Crewther, Sheila G.
Visual Magnocellular Function in Perceptual Disorders
title Visual Magnocellular Function in Perceptual Disorders
title_full Visual Magnocellular Function in Perceptual Disorders
title_fullStr Visual Magnocellular Function in Perceptual Disorders
title_full_unstemmed Visual Magnocellular Function in Perceptual Disorders
title_short Visual Magnocellular Function in Perceptual Disorders
title_sort visual magnocellular function in perceptual disorders
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5393755/
http://dx.doi.org/10.1068/ic416
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