Bilinguals of Two Spoken Languages Have More Grey Matter in Their Brains

First Posted: Jul 17, 2015 07:29 AM EDT

Bilinguals may actually have more grey matter than the average person. Scientists have discovered that people who speak two languages have more grey matter in the executive control region of the brain.

In past decades, much has changed about the understanding of bilingualism. Early on, bilingualism was actually thought to be a disadvantage because the presence of two vocabularies would lead to delayed language development in children. Since then, though, researchers have found that bilingual children perform better on tasks that require attention, inhibition and short-term memory, collectively termed "executive control."

Although research has shown some advantages for bilinguals, there is still skepticism about whether these advantages are actually presence, since they're not observed in all studies. That's why researchers decided to take a closer look.

"Inconsistencies in the reports about the bilingual advantage stem primarily from the variety of tasks that are used in attempts to elicit the advantage," said Guinevere Eden, one of the researchers, in a news release. "Given this concern, we took a different approach and instead compared grey matter volume between adult bilinguals and monolinguals. We reasoned that 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. And in fact greater gray matter for bilinguals was observed in frontal and parietal brain regions that are involved in executive control."

Grey matter of the brain has been shown to differ in volume as a function of people's experiences. In this case, though, the researchers found the grey matter associated with Spanish-English bilinguals had greater grey matter. With that said, there was no evidence for greater grey matter in ASL-English bilinguals. This suggests that the management of two spoken languages in the same modality, rather than simply a larger vocabulary, leads to the differences.

The findings are published in the journal Cerebral Cortex.