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Dyslexia and configural perception of character sequences

Developmental dyslexia is a complex and heterogeneous disorder characterized by unexpected difficulty in learning to read. Although it is considered to be biologically based, the degree of variation has made the nature and locus of dyslexia difficult to ascertain. Hypotheses regarding the cause have...

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Autores principales: Houpt, Joseph W., Sussman, Bethany L., Townsend, James T., Newman, Sharlene D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4406005/
https://www.ncbi.nlm.nih.gov/pubmed/25954234
http://dx.doi.org/10.3389/fpsyg.2015.00482
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author Houpt, Joseph W.
Sussman, Bethany L.
Townsend, James T.
Newman, Sharlene D.
author_facet Houpt, Joseph W.
Sussman, Bethany L.
Townsend, James T.
Newman, Sharlene D.
author_sort Houpt, Joseph W.
collection PubMed
description Developmental dyslexia is a complex and heterogeneous disorder characterized by unexpected difficulty in learning to read. Although it is considered to be biologically based, the degree of variation has made the nature and locus of dyslexia difficult to ascertain. Hypotheses regarding the cause have ranged from low-level perceptual deficits to higher order cognitive deficits, such as phonological processing and visual-spatial attention. We applied the capacity coefficient, a measure obtained from a mathematical cognitive model of response times to measure how efficiently participants processed different classes of stimuli. The capacity coefficient was used to test the extent to which individuals with dyslexia can be distinguished from normal reading individuals based on their ability to take advantage of word, pronounceable non-word, consonant sequence or unfamiliar context when categorizing character strings. Within subject variability of the capacity coefficient across character string types was fairly regular across normal reading adults and consistent with a previous study of word perception with the capacity coefficient—words and pseudowords were processed at super-capacity and unfamiliar characters strings at limited-capacity. Two distinct patterns were observed in individuals with dyslexia. One group had a profile similar to the normal reading adults while the other group showed very little variation in capacity across string-type. It is possible that these individuals used a similar strategy for all four string-types and were able to generalize this strategy when processing unfamiliar characters. This difference across dyslexia groups may be used to identify sub-types of the disorder and suggest significant differences in word level processing among these subtypes. Therefore, this approach may be useful in further delineating among types of dyslexia, which in turn may lead to better understanding of the etiologies of dyslexia.
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spelling pubmed-44060052015-05-07 Dyslexia and configural perception of character sequences Houpt, Joseph W. Sussman, Bethany L. Townsend, James T. Newman, Sharlene D. Front Psychol Psychology Developmental dyslexia is a complex and heterogeneous disorder characterized by unexpected difficulty in learning to read. Although it is considered to be biologically based, the degree of variation has made the nature and locus of dyslexia difficult to ascertain. Hypotheses regarding the cause have ranged from low-level perceptual deficits to higher order cognitive deficits, such as phonological processing and visual-spatial attention. We applied the capacity coefficient, a measure obtained from a mathematical cognitive model of response times to measure how efficiently participants processed different classes of stimuli. The capacity coefficient was used to test the extent to which individuals with dyslexia can be distinguished from normal reading individuals based on their ability to take advantage of word, pronounceable non-word, consonant sequence or unfamiliar context when categorizing character strings. Within subject variability of the capacity coefficient across character string types was fairly regular across normal reading adults and consistent with a previous study of word perception with the capacity coefficient—words and pseudowords were processed at super-capacity and unfamiliar characters strings at limited-capacity. Two distinct patterns were observed in individuals with dyslexia. One group had a profile similar to the normal reading adults while the other group showed very little variation in capacity across string-type. It is possible that these individuals used a similar strategy for all four string-types and were able to generalize this strategy when processing unfamiliar characters. This difference across dyslexia groups may be used to identify sub-types of the disorder and suggest significant differences in word level processing among these subtypes. Therefore, this approach may be useful in further delineating among types of dyslexia, which in turn may lead to better understanding of the etiologies of dyslexia. Frontiers Media S.A. 2015-04-22 /pmc/articles/PMC4406005/ /pubmed/25954234 http://dx.doi.org/10.3389/fpsyg.2015.00482 Text en Copyright © 2015 Houpt, Sussman, Townsend and Newman. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Psychology
Houpt, Joseph W.
Sussman, Bethany L.
Townsend, James T.
Newman, Sharlene D.
Dyslexia and configural perception of character sequences
title Dyslexia and configural perception of character sequences
title_full Dyslexia and configural perception of character sequences
title_fullStr Dyslexia and configural perception of character sequences
title_full_unstemmed Dyslexia and configural perception of character sequences
title_short Dyslexia and configural perception of character sequences
title_sort dyslexia and configural perception of character sequences
topic Psychology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4406005/
https://www.ncbi.nlm.nih.gov/pubmed/25954234
http://dx.doi.org/10.3389/fpsyg.2015.00482
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