Abstract
Background: Converging evidence indicates a functional disruption in the neural systems
for reading in adults with dyslexia. We examined brain activation patterns in dyslexic
and nonimpaired children during pseudoword and real-word reading tasks that required
phonologic analysis (i.e., tapped the problems experienced by dyslexic children in
sounding out words).
Methods: We used functional magnetic resonance imaging (fMRI) to study 144 right-handed
children, 70 dyslexic readers, and 74 nonimpaired readers as they read pseudowords
and real words.
Results: Children with dyslexia demonstrated a disruption in neural systems for reading
involving posterior brain regions, including parietotemporal sites and sites in the
occipitotemporal area. Reading skill was positively correlated with the magnitude
of activation in the left occipitotemporal region. Activation in the left and right
inferior frontal gyri was greater in older compared with younger dyslexic children.
Conclusions: These findings provide neurobiological evidence of an underlying disruption
in the neural systems for reading in children with dyslexia and indicate that it is
evident at a young age. The locus of the disruption places childhood dyslexia within
the same neurobiological framework as dyslexia, and acquired alexia, occurring in
adults.
Keywords
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Article info
Publication history
Accepted:
February 5,
2002
Received in revised form:
January 23,
2002
Received:
November 2,
2001
Identification
Copyright
© 2002 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
