Reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency.

The acquisition of letter-speech sound associations is one of the basic requirements for fluent reading acquisition and its failure may contribute to reading difficulties in developmental dyslexia. Here we investigated event-related potential (ERP) measures of letter-speech sound integration in 9-ye...

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Main Authors: Gojko Žarić, Gorka Fraga González, Jurgen Tijms, Maurits W van der Molen, Leo Blomert, Milene Bonte
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4199667?pdf=render
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author Gojko Žarić
Gorka Fraga González
Jurgen Tijms
Maurits W van der Molen
Leo Blomert
Milene Bonte
author_facet Gojko Žarić
Gorka Fraga González
Jurgen Tijms
Maurits W van der Molen
Leo Blomert
Milene Bonte
author_sort Gojko Žarić
collection DOAJ
description The acquisition of letter-speech sound associations is one of the basic requirements for fluent reading acquisition and its failure may contribute to reading difficulties in developmental dyslexia. Here we investigated event-related potential (ERP) measures of letter-speech sound integration in 9-year-old typical and dyslexic readers and specifically test their relation to individual differences in reading fluency. We employed an audiovisual oddball paradigm in typical readers (n = 20), dysfluent (n = 18) and severely dysfluent (n = 18) dyslexic children. In one auditory and two audiovisual conditions the Dutch spoken vowels/a/and/o/were presented as standard and deviant stimuli. In audiovisual blocks, the letter 'a' was presented either simultaneously (AV0), or 200 ms before (AV200) vowel sound onset. Across the three children groups, vowel deviancy in auditory blocks elicited comparable mismatch negativity (MMN) and late negativity (LN) responses. In typical readers, both audiovisual conditions (AV0 and AV200) led to enhanced MMN and LN amplitudes. In both dyslexic groups, the audiovisual LN effects were mildly reduced. Most interestingly, individual differences in reading fluency were correlated with MMN latency in the AV0 condition. A further analysis revealed that this effect was driven by a short-lived MMN effect encompassing only the N1 window in severely dysfluent dyslexics versus a longer MMN effect encompassing both the N1 and P2 windows in the other two groups. Our results confirm and extend previous findings in dyslexic children by demonstrating a deficient pattern of letter-speech sound integration depending on the level of reading dysfluency. These findings underscore the importance of considering individual differences across the entire spectrum of reading skills in addition to group differences between typical and dyslexic readers.
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spelling doaj.art-1a2cadd83fd04e2e8503e0976b32fd182022-12-22T00:29:23ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-01910e11033710.1371/journal.pone.0110337Reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency.Gojko ŽarićGorka Fraga GonzálezJurgen TijmsMaurits W van der MolenLeo BlomertMilene BonteThe acquisition of letter-speech sound associations is one of the basic requirements for fluent reading acquisition and its failure may contribute to reading difficulties in developmental dyslexia. Here we investigated event-related potential (ERP) measures of letter-speech sound integration in 9-year-old typical and dyslexic readers and specifically test their relation to individual differences in reading fluency. We employed an audiovisual oddball paradigm in typical readers (n = 20), dysfluent (n = 18) and severely dysfluent (n = 18) dyslexic children. In one auditory and two audiovisual conditions the Dutch spoken vowels/a/and/o/were presented as standard and deviant stimuli. In audiovisual blocks, the letter 'a' was presented either simultaneously (AV0), or 200 ms before (AV200) vowel sound onset. Across the three children groups, vowel deviancy in auditory blocks elicited comparable mismatch negativity (MMN) and late negativity (LN) responses. In typical readers, both audiovisual conditions (AV0 and AV200) led to enhanced MMN and LN amplitudes. In both dyslexic groups, the audiovisual LN effects were mildly reduced. Most interestingly, individual differences in reading fluency were correlated with MMN latency in the AV0 condition. A further analysis revealed that this effect was driven by a short-lived MMN effect encompassing only the N1 window in severely dysfluent dyslexics versus a longer MMN effect encompassing both the N1 and P2 windows in the other two groups. Our results confirm and extend previous findings in dyslexic children by demonstrating a deficient pattern of letter-speech sound integration depending on the level of reading dysfluency. These findings underscore the importance of considering individual differences across the entire spectrum of reading skills in addition to group differences between typical and dyslexic readers.http://europepmc.org/articles/PMC4199667?pdf=render
spellingShingle Gojko Žarić
Gorka Fraga González
Jurgen Tijms
Maurits W van der Molen
Leo Blomert
Milene Bonte
Reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency.
PLoS ONE
title Reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency.
title_full Reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency.
title_fullStr Reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency.
title_full_unstemmed Reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency.
title_short Reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency.
title_sort reduced neural integration of letters and speech sounds in dyslexic children scales with individual differences in reading fluency
url http://europepmc.org/articles/PMC4199667?pdf=render
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