White matter correlates of reading subskills in children

White matter correlates of reading subskills in children

First Author: Alexandra Cross -- University of Western Ontario
Additional authors/chairs: 
Jessica Lammert; Christine Stager; Maureen Lovett; Karen Steinbach; Jan Frijters; Lisa Archibald; Marc Joanisse
Keywords: Reading development, Diffusion Tensor Imaging, Neuroimaging, Developmental neuroscience, Reading disability
Abstract / Summary: 

Purpose: Reading is a cognitive process which involves integration of a number of subskills, and relies on coordinated processing across many regions of the brain. Previous magnetic resonance imaging (MRI) studies of children have tended to correlate a single reading measure with neural connectivity. However, studies of adults have demonstrated that separable subskills associated with reading relate differently to connectivity in various white matter tracts of the brain. The present study extends this research to children to examine the relationship between reading subskills and regional white matter tract integrity.
Methods: Participants were children enrolled in grades 4 to 6 in local schools with a range of reading abilities, including a subset of children identified with reading disability. Children completed a diffusion tensor imaging (DTI) scan as a measure of white matter microstructure, a high-resolution anatomical MRI scan, and a behavioural testing session in which reading fluency, phonological decoding, rapid naming, and reading comprehension were assessed.
Results: Analyses examined the relationship between reading subskills and fractional anisotropy in the arcuate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and uncinate fasciculus. A hemispheric dissociation was observed in which better reading subskills were associated with greater white matter integrity in some left hemisphere tracts, while poorer reading subskills were associated with greater white matter integrity in some right hemisphere tracts.
Conclusions: The findings provide insight into how various reading subskills relate to white matter microstructure, as well as how connectivity may differ in children with reading disability.