White matter correlates of reading subskills in children with and without reading disability.

Individual differences in reading ability are associated with characteristics of white matter microstructure in the brain. However, previous studies have largely measured reading as a single construct, resulting in difficulty characterizing the role of structural connectivity in discrete subskills of reading. The present study used diffusion tensor imaging to examine how white matter microstructure, measured by fractional anisotropy (FA), relates to individual differences in reading subskills in children aged 8 to 14 (n = 65). Findings showed positive correlations between FA of the left arcuate fasciculus and measures of single word reading and rapid naming abilities. Negative correlations were observed between FA of the right inferior longitudinal fasciculus and bilateral uncinate fasciculi, and reading subskills, particularly reading comprehension. The results suggest that although reading subskills rely to some extent on shared tracts, there are also distinct characteristics of white matter microstructure supporting different components of reading ability in children.