Peak Wellbeing
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Bilingualism Boosts Your Brain for Stronger Cognitive Function

Speaking — and learning — a second language can strengthen your brain’s executive control systems and functions related to attention control, thinking, decision making, and problem solving

Dr. Yang Hwajin visits Singaporean schools to run cognitive tests on youngsters who have a low socioeconomic status. She found the children who were bilingual (speak multiple languages) showed a higher level of cognitive functioning on tests than monolinguals (who speak one language). In fact, this effect was the same the younger and younger she went: babies who couldn’t even speak yet performed better if they had been exposed to different languages in their environment. Merely overhearing family members speaking both Mandarin and Cantonese, for example, gave them a cognitive boost.

Early bilingual research from around the 1950s would have warned these Singaporean parents against exposing their children to more than one language. The general consensus at the time was this confuses children and hinders their development, giving them an unfortunate bilingual handicap.

But since then, decades of studies have disagreed: other than some slight disadvantages around vocabulary, bilingualism improves higher level cognitive function such as executive control. The only overlap between the old and new way of thinking is the idea that learning a second language fundamentally changes our brain structure and function, especially when we’re young. In fact, bilingualism can stamp the mind with a “neural signature,” visible on fMRI scans, demonstrating that bilinguals process language in a predictable, recognizable pattern that’s different from their monolingual peers. And research like that of Yang Hwajin suggests that teaching children a second language can be a proactive cognitive intervention that counteracts the effects of growing up in an underprivileged environment.

A Second Set of Weights to Train Your Brain

Bilingualism exercises and therefore strengthens the executive control systems based in the brain’s prefrontal cortex, including functions related to attention control, thinking, decision making, and problem solving. It all boils down to cognitive focus and the ability to suppress a language while activating another one. Bilinguals constantly decide whether the words they hear belong to one language or the other, and when they respond, they must choose which words to use from more than one mental dictionary (also known as a lexicon).

Linguistic psychologist and researcher Dr. Viorica Marian studies this cognitive inhibition and explains, “It’s like a stop light…Bilinguals are always giving the green light to one language and red to another. When you have to do that all the time, you get really good at inhibiting the words you don’t need.” A study by Marian and team used fMRI to scan the brains of bilinguals and monolinguals during a task in which they had to focus on a word and ignore irrelevant or conflicting information. The monolinguals’ brains “lit up” more in inhibitory control regions of the brain, suggesting that they need more brain activity or “work” to focus and filter information, while bilinguals need less “work” to perform the same task.

As Marian puts it, when we learn a second language, our executive control system gets a second set of weights to train with. Bilinguals who have been training with more weight their whole lives are stronger for it, though the benefits are also seen in people who learn new languages after childhood.

Enhanced executive control helps bilinguals of all ages and in various areas of their lives. This has been demonstrated in many studies, from better attentional control in preschoolers to teenagers who can process sounds more efficiently amid distracting noise to elderly bilinguals who cope better with brain deterioration and delay Alzheimer’s onset by four or five years.

A Matter of Preservation

And research on the actual structure of the brain shows that bilinguals get support from a higher number of neural connections, through gray and white matter density. White matter, which is known to decline with age, is actually preserved better in elderly bilinguals than in elderly monolinguals, providing greater connectivity to support executive function. Meanwhile, researchers at University College London found that bilingual people have more gray matter density in a section of the brain responsible for storing vocabulary, called the posterior supramarginal gyrus.

Brain area with higher gray matter density in bilinguals

(Fun fact: people who speak tonal languages like Chinese have additional gray matter density in other areas of their brain, suggesting that these languages have different vocabulary storage systems. Tonal languages convey the meaning of a word not only through letters and pronunciation but the way the speaker intones or “sings” the word.)

This is all good and well for people who grew up with more than one mother tongue. But what about those of us who learned a language later in life, like high school French or some Japanese we picked up during travels? And if we decide to start studying Norwegian once we retire, will we still get cognitive benefits?

Even though the effects of bilingualism on the brain are strongest when we learn early, learning a new language is beneficial at any age. It’s is a new experience that strengthens neural connections, just like learning how to juggle or playing brain training games. As longtime bilingualism researcher Dr. Ellen Bialystock puts it, “Nothing I can think of is more difficult or more cognitively engaging than trying to learn another language … an excellent activity to maintain cognitive function.”

Are you convinced and ready to learn some new words? Vámonos (let’s go)!



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