A new study suggests people who speak two languages have more gray matter in the executive control region of the brain.
Earlier, bilingualism was thought to be a disadvantage because the presence of two vocabularies would lead to delayed language development in children.
The findings added to the growing understanding of how long-term experience with a particular skill — in this case management of two languages — changes the brain.
The researchers compared gray matter in bilinguals of American Sign Language (ASL) and spoken English with monolingual users of English.
“The experience with two languages and the increased need for cognitive control to use them appropriately would result in brain changes in Spanish-English bilinguals when compared with English-speaking monolinguals,” said senior author Guinevere Eden, director for the Center for the Study of Learning at Georgetown University Medical Center (GUMC).
The team compared gray matter volume between adult bilinguals and monolinguals.
Greater gray matter for bilinguals was observed in frontal and parietal brain regions that are involved in executive control.
Gray matter of the brain has been shown to differ in volume as a function of people’s experiences.
“Our aim was to address whether the constant management of two spoken languages leads to cognitive advantages and the larger gray matter we observed in Spanish-English bilinguals, or whether other aspects of being bilingual, such as the large vocabulary associated with having two languages, could account for this,” explained lead author Olumide Olulade, a fellow at GUMC.
“The management of two spoken languages in the same modality, rather than simply a larger vocabulary, leads to the differences we observed in the Spanish-English bilinguals,” Olulade said.