Bilingual Brains May Be More Efficient, Less Prone to Dementia

Bilingual brains are more efficient and economical with cognitive resources than their monolingual counterparts, which may help stave off symptoms of aging and dementia, according to new research published in the journal Neurolinguistics.

For the study, a team of Canadian researchers led by Ana Inés Ansaldo, Ph.D., a professor at Université de Montréal, compared functional brain connections between bilingual seniors and monolingual seniors.

The findings revealed that years of bilingualism appears to change how the brain carries out tasks, particularly those that require concentrating on one piece of information without becoming distracted by other information. This makes the brain more efficient and economical with its resources.

“After years of daily practice managing interference between two languages, bilinguals become experts at selecting relevant information and ignoring information that can distract from a task,” said Ansaldo, a researcher at the Centre de recherche de l’Institut universitaire de gériatrie de Montréal.

The researchers asked both bilingual and monolingual seniors to perform a task that involved focusing on visual information while ignoring spatial information. As the seniors performed the task, the researchers compared the networks in different areas of their brains.

They found that monolinguals recruited a larger circuit with multiple connections, whereas bilinguals recruited a smaller circuit that was more appropriate for the required information.

The participants completed a task that required them to focus on visual information (the color of an object) while ignoring spatial information (the position of the object). The researchers observed that the monolingual brain allocates a number of regions linked to visual and motor function and interference control, which are located in the frontal lobes.

In other words, the monolingual brain requires multiple brain regions to do the task.

“In this case, bilinguals showed higher connectivity between visual processing areas located at the back of the brain. This area is specialized in detecting the visual characteristics of objects and therefore is specialized in the task used in this study. These data indicate that the bilingual brain is more efficient and economical, as it recruits fewer regions and only specialized regions,” said Ansaldo.

Bilinguals essentially have two cognitive benefits. First, they have more centralized and specialized functional connections which saves resources compared to the multiple and more diverse brain areas allocated by monolinguals to accomplish the same task. Second, bilinguals achieve the same result by not using the brain’s frontal regions, which are vulnerable to aging.

This may explain why the brains of bilinguals are better equipped at staving off the signs of cognitive aging or dementia.

“We have observed that bilingualism has a concrete impact on brain function and that this may have a positive impact on cognitive aging,” said Ansaldo.

“We now need to study how this function translates to daily life, for example, when concentrating on one source of information instead of another, which is something we have to do every day. And we have yet to discover all the benefits of bilingualism.”

Source: University of Montreal