The age at which children learn a second language can have a significant bearing on the structure of their adult brain, according to a new joint study by the Montreal Neurological Institute and Hospital at McGill University and Oxford University. Many people learn to speak more than one language during their lifetime and do so with great proficiency particularly if the languages are learned simultaneously or from early in development.
The study concludes that the pattern of brain development is similar if a person learn one or two language from birth. However, learning a second language later on in childhood after gaining proficiency in the first language does, in fact, modify the brain’s structure, specifically the brain’s inferior frontal cortex. The left inferior frontal cortex became thicker and the right inferior frontal cortex became thinner. The cortex is a multi-layered mass of neurons that plays a major role in cognitive functions such as thought, language, consciousness and memory.
The study suggests that the task of acquiring a second language after infancy stimulates new neural growth and connections among neurons in ways seen in acquiring complex motor skills such as juggling. The study’s authors speculate that the difficulty that some people have in learning a second language later in life could be explained at the structural level.