Language exposure and brain myelination in early development

Abstract

The language environment to which children are exposed has an impact on later language and cognitive abilities as well as on brain development; however, it is unclear how early such impacts emerge. This study investigates the effects of children's early language environment and socioeconomic status (SES) on brain structure in infancy at both 6 and 30 months of age. We used magnetic resonance imaging (MRI) to quantify concentrations of myelin in specific fiber tracts in the brain. Our central question was whether Language ENvironment Analysis (LENA) measures from in-home recording devices and SES measures of maternal education and family income predicted myelin concentrations over development. Results show relationships between amount of in-home adult input and myelination in the white matter tracts most associated with language. Right hemisphere regions also show an association with SES, with older children from a higher SES background who were exposed to more adult input showing greater concentrations of myelin in language-related areas. We discuss these results in relation with the current literature and implications for future language research and intervention.

Environmental contributions to cognitive development: The role of cognitive stimulation

“…Such associations are also evident in early childhood. For example, recent work demonstrates that a greater number of conversational turns between infants' vocalizations and adult responses, and amount of adult language a child is exposed to is correlated with enhanced white matter integrity (Huber et al, 2023) and myelination (Fibla et al, 2023) in crucial neural pathways that support language development. Additionally, the frequency of conversational exchanges, rather than incidental overheard speech, are linked to resting-state functional connectivity of infant brain networks associated with language processing (King et al, 2021).…”