Article

The angular gyrus in developmental dyslexia: task-specific differences in functional connectivity within posterior cortex.

Department of Pediatrics, Yale University School of Medicine, P.O. Box 3333, New Haven, CT 06510-8064, USA.
Psychological Science (impact factor: 4.43). 02/2000; 11(1):51-6. pp.51-6
Source: PubMed

ABSTRACT Converging evidence from neuroimaging studies of developmental dyslexia reveals dysfunction at posterior brain regions centered in and around the angular gyrus in the left hemisphere. We examined functional connectivity (covariance) between the angular gyrus and related occipital and temporal lobe sites, across a series of print tasks that systematically varied demands on phonological assembly. Results indicate that for dyslexic readers a disruption in functional connectivity in the language-dominant left hemisphere is confined to those tasks that make explicit demands on assembly. In contrast, on print tasks that do not require phonological assembly, functional connectivity is strong for both dyslexic and nonimpaired readers. The findings support the view that neurobiological anomalies in developmental dyslexia are largely confined to the phonological-processing domain. In addition, the findings suggest that right-hemisphere posterior regions serve a compensatory role in mediating phonological performance in dyslexic readers.

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Keywords

angular gyrus
 
compensatory role
 
Converging evidence
 
developmental dyslexia
 
disruption
 
dysfunction
 
dyslexic
 
dyslexic readers
 
findings support
 
functional connectivity
 
left hemisphere
 
mediating phonological performance
 
neuroimaging studies
 
nonimpaired readers
 
phonological assembly
 
phonological-processing domain
 
posterior brain regions
 
right-hemisphere posterior regions
 
temporal lobe sites