There is increasing evidence that bilingualism can affect the functioning of the brain. Older, lifelong bilinguals demonstrated better cognitive abilities in tasks requiring increased cognitive control.
These cognitive effects are most pronounced in bilingual people who speak two languages in their daily lives compared to those who speak a second language but do not use it frequently. Our new research has drawn attention to structural improvements in the brain that are now observed in people who are bilingual immersed themselves in bilinguals.
Bilingualism for children affects both the main types of brain tissue and the structure of the brain, including gray matter and white matter. The neurons in our brain have two different anatomical features: the cell bodies where all information, thinking and planning processes take place, and their axons, which are the main pathways that connect brain areas and transfer information between them.
Cell bodies are organized around the surface of the brain – gray matter – and all axons converge beneath it and connect to white matter.
We call it white matter because axons are wrapped in a fatty layer of myelin that allows for better neuronal communication – the transfer of information around the brain. Myelin acts as an "insulation" that prevents it from "leaking" from the axon during transmission.