Subcortical malleability as a result of cognitively challenging experiences: the case of bi-/multilingualism

Experience-based neuroplasticity in the healthy brain is a well-documented finding, with functional and structural adaptations in cortical and subcortical structures reported as the brain’s response to cognitively challenging experiences. These experiences include bi-/multilingualism: speaking more than one language entails increased cognitive demands related to language acquisition, processing and control, which affect subcortical structures subserving these processes, including the basal ganglia and the cerebellum. This paper reviews evidence on bilingualism-induced subcortical neuroplasticity at the level of brain structure, function, and metabolism and explores how it interacts with brain decline. As such, it highlights bi-/multilingualism as a test case for studying long-term neuroplastic effects in the brain. • Cognitively challenging experiences cause structural and functional brain changes. • These include bi-/multilingualism, with its increased cognitive control demands. • The basal ganglia, thalamus, and cerebellum are all affected by bi-/multilingualism. • Adaptations are dynamic and nonlinear in response to changing bilingualism demands. • These adaptations follow the principles of experience-based neuroplasticity.