How does SES influence the brain circuitry for literacy? Modeling the association between SES, oral language, white matter integrity, and reading.

Reading is pivotal for educational and occupational success, hence, understanding the factors contributing to reading skill variation is a major educational objective. Although cognitive and neurobiological factors that influence reading are well documented, the contributions of environmental factors, such as socioeconomic status (SES), fiv to reading-related neurobiology are relatively understudied. Studies have shown that SES predicts reading and the integrity of reading-related white matter tracts; however, the direct and indirect contributions of SES to reading via white matter integrity remain undifferentiated. Further, while oral language (both phonological awareness [PA] and vocabulary) has been positively associated with both SES and reading, only a few studies have attempted to model the SES-reading association via oral language, and none of them included white matter integrity. The current study closes these gaps by using Structural Equation Modeling in a large sample of children from the Healthy Brain Network biobank, testing the (in)direct paths by which SES (parental education) influences reading through oral language and white matter integrity. Results reveal an effect of SES on reading that is indirectly affected by oral language, though not by white matter integrity. These findings reinforce the role of oral language skills as a key pathway linking SES and reading.