Neuropsychological effects of second language exposure in Down syndrome

Background While it has been common practice to discourage second language learning in neurodevelopmental disorders involving language impairment, little is known about the effects of second language exposure (SLE) on broader cognitive function in these children. Past studies have not found differences on language tasks in children with Down syndrome (DS) and SLE. We expand on this work to determine the effects on the broader cognitive profile, including tests tapping deficits on neuropsychological measures of prefrontal and hippocampal function. Method This study examined the specific cognitive effects of SLE in children with DS (aged 7–18 years). Children with SLE (n = 13: SLE predominantly Spanish) and children from monolingual homes (n = 28) were assessed on a standardised battery of neuropsychological tests developed for DS, the Arizona Cognitive Test Battery. The current exposure level to a language other than English in the SLE group was greater than 4 h per day on average. Results No group differences were observed for any outcome, and level of exposure was also not linearly related to neuropsychological outcomes, several of which have been shown to be impaired in past work. Conclusion There were no measurable effects of SLE on neuropsychological function in this sample of children with DS. Potential clinical implications of these findings are discussed.