Examining the relationship between shared book reading at home, white matter organization in kindergarten, and subsequent language and reading abilities: a longitudinal investigation

Parent-child language interaction in early childhood carries long-term implications for children’s language and reading development. Naturalistic conversational interaction, in particular, has been linked to white matter organization of neural pathways critical for language and reading. Yet parent-child shared book reading serves a unique role for language interaction as it exposes children to diverse concepts and sophisticated vocabulary and syntax beyond the scope of everyday conversational interaction. Despite this, it remains unclear whether shared reading also contributes to white matter mechanisms subserving language and reading development. If so, to what extent do these environmentally-associated changes in white matter organization relate to subsequent reading outcomes? To address these questions, the present longitudinal study examined shared book reading and white matter organization in kindergarten in relation to subsequent language and reading outcomes among 77 typically-developing children. Findings reveal positive associations between the number of hours children are read to weekly in kindergarten and fractional anisotropy of the left arcuate fasciculus, as well as left lateralization of the superior longitudinal fasciculus (SLF). Further, left lateralization of the SLF in these kindergarteners is associated with subsequent reading abilities in second grade. Mediation analyses further reveal that the amount children are read to weekly is indirectly associated with second-grade reading abilities via left lateralization of the SLF. All results are significant when controlling for children’s age and their family’s socioeconomic status. This study provides the first evidence illuminating how white matter structure in relation to shared reading experiences in kindergarten is associated with subsequent school-age reading outcomes. These results carry implications for understanding specific contexts of parent-child language interaction that may support neurocognitive development, independent of socioeconomic factors.