White matter microstructure integrity in relation to reading proficiency☆

Abstract

Components of reading proficiency such as accuracy, fluency, and comprehension require the successful coordination of numerous, yet distinct, cortical regions. Underlying white matter tracts allow for communication among these regions. This study utilized unique residualized tract – based spatial statistics methodology to identify the relations of white matter microstructure integrity to three components of reading proficiency in 49 school - aged children with typically developing phonological decoding skills and 27 readers with poor decoders. Results indicated that measures of white matter integrity were differentially associated with components of reading proficiency. In both typical and poor decoders, reading comprehension correlated with measures of integrity of the right uncinate fasciculus; reading comprehension was also related to the left inferior longitudinal fasciculus in poor decoders. Also in poor decoders, word reading fluency was related to the right uncinate and left inferior fronto - occipital fasciculi. Word reading was unrelated to white matter integrity in either group. These findings expand our knowledge of the association between white matter integrity and different elements of reading proficiency.

White matter properties associated with pre‐reading skills in 6‐year‐old children born preterm and at term

“…Consistent with our hypothesis, the association between mean fractional anisotropy of the UF‐R and core language scores was moderated by birth group. The exact function of the uncinate fasciculus is debated; however, the present findings are consistent with prior studies that have found associations between properties of the uncinate fasciculus and language and reading abilities . The uncinate fasciculus connects with anterior projections of the inferior fronto‐occipital fasciculus, a tract considered in cognitive models of language and reading to be part of the ventral stream, and to be relevant for mapping sound to meaning.…”

“…The exact function of the uncinate fasciculus is debated; however, the present findings are consistent with prior studies that have found associations between properties of the uncinate fasciculus and language and reading abilities. 20,39 The uncinate fasciculus connects with anterior projections of the inferior fronto-occipital fasciculus, a tract considered in cognitive models of language and reading to be part of the ventral stream, 34 and to be relevant for mapping sound to meaning. A previous study demonstrated altered white matter properties in the uncinate fasciculus in adolescents born preterm compared with peers born at term, and found associations between fractional anisotropy of the UF-R and scores on a semantic language task.…”

“…Reading and its related subskills are known to activate a distributed network of cortical grey matter areas that are connected via complex networks of white matter pathways (tracts) . Fractional anisotropy of specific white matter tracts, such as the arcuate, superior longitudinal, and uncinate fasciculi, has been associated with reading, phonological awareness, and language skills in older, typically developing children and adults . Studies involving children born preterm have also observed associations between white matter properties and reading .…”

“…[15][16][17] Fractional anisotropy of specific white matter tracts, such as the arcuate, superior longitudinal, and uncinate fasciculi, has been associated with reading, phonological awareness, and language skills in older, typically developing children and adults. [18][19][20][21] Studies involving children born preterm have also observed associations between white matter properties and reading. 19,22 However, a recent study found that the direction of these associations varied between the two birth groups, suggesting a differing neurobiology for reading in children and adolsecents born preterm and at term.…”

Functional Anatomy of the Inferior Longitudinal Fasciculus: From Historical Reports to Current Hypotheses

“…For example, inter-individual variations in the microstructural properties of both the left and right ILFs in people with normal intelligence are correlated with word reading fluency and reading comprehension ( Horowitz-Kraus et al, 2014 ). This agrees with the fact that difficulties in reading comprehension were found to be associated with abnormalities of the right ILF in adolescents born preterm ( Feldman et al, 2012 ) and abnormalities of the left ILF in poor decoders ( Arrington et al, 2017 ). Lastly, these findings are consistent with the observation that the rate of maturation of the ILF covaries with children’s reading abilities ( Yeatman et al, 2012 ).…”