Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.

Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to exa...

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Main Authors: Ying Zhang, Susan Whitfield-Gabrieli, Joanna A Christodoulou, John D E Gabrieli
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3692444?pdf=render
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author Ying Zhang
Susan Whitfield-Gabrieli
Joanna A Christodoulou
John D E Gabrieli
author_facet Ying Zhang
Susan Whitfield-Gabrieli
Joanna A Christodoulou
John D E Gabrieli
author_sort Ying Zhang
collection DOAJ
description Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow's direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.
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spelling doaj.art-3d0da0a74a774e56952437564851f8b72022-12-22T00:20:56ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0186e6733110.1371/journal.pone.0067331Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.Ying ZhangSusan Whitfield-GabrieliJoanna A ChristodoulouJohn D E GabrieliReading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow's direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.http://europepmc.org/articles/PMC3692444?pdf=render
spellingShingle Ying Zhang
Susan Whitfield-Gabrieli
Joanna A Christodoulou
John D E Gabrieli
Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.
PLoS ONE
title Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.
title_full Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.
title_fullStr Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.
title_full_unstemmed Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.
title_short Atypical balance between occipital and fronto-parietal activation for visual shape extraction in dyslexia.
title_sort atypical balance between occipital and fronto parietal activation for visual shape extraction in dyslexia
url http://europepmc.org/articles/PMC3692444?pdf=render
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