Neural dissociation of phonological and visual attention span disorders in developmental dyslexia: FMRI evidence from two case reports

C. Peyrin*, M. Lanier, J. F. Demonet, C. Pernet, M. Baciu, J. F. Le Bas, S. Valdois

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

A dissociation between phonological and visual attention (VA) span disorders has been reported in dyslexic children. This study investigates whether this cognitively-based dissociation has a neurobiological counterpart through the investigation of two cases of developmental dyslexia. LL showed a phonological disorder but preserved VA span whereas FG exhibited the reverse pattern. During a phonological rhyme judgement task, LL showed decreased activation of the left inferior frontal gyrus whereas this region was activated at the level of the controls in FG. Conversely, during a visual categorization task, FG demonstrated decreased activation of the parietal lobules whereas these regions were activated in LL as in the controls. These contrasted patterns of brain activation thus mirror the cognitive disorders' dissociation. These findings provide the first evidence for an association between distinct brain mechanisms and distinct cognitive deficits in developmental dyslexia, emphasizing the importance of taking into account the heterogeneity of the reading disorder. (C) 2012 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)381-394
Number of pages14
JournalBrain and Language
Volume120
Issue number3
DOIs
Publication statusPublished - Mar 2012

Keywords

  • SURFACE DYSLEXIA
  • Broca's area
  • LANGUAGE
  • Parietal dysfunction
  • READING-DISABILITY
  • Visual attention span
  • CHILDREN
  • FRONTAL-CORTEX
  • BRAIN ACTIVATION
  • FUNCTIONAL MRI
  • Developmental dyslexia
  • Dyslexia subtypes
  • EVENT-RELATED FMRI
  • WORD FORM AREA
  • Phonological disorder
  • DUAL-ROUTE
  • Heterogeneity

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