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Speaking Two Languages May Help the Aging Brain

Research

Photo by ONEINCHPUNCH / GETTY IMAGES.


Psycholinguist Mark Antoniou of Western Sydney University in Australia argues that bilingualism—as he defines it, using at least two languages in your daily life—may benefit our brains, especially as we age.

Q: What are the benefits of bilingualism?

A: The first main advantage involves what’s loosely referred to as executive function. This describes skills that allow you to control, direct and manage your attention, as well as your ability to plan. It also helps you ignore irrelevant information and focus on what’s important. Because a bilingual person has mastery of two languages, and the languages are activated automatically and subconsciously, the person is constantly managing the interference of the languages so that she or he doesn’t say the wrong word in the wrong language at the wrong time. The brain areas responsible for that are also used when you’re trying to complete a task while there are distractions. The task could have nothing to do with language; it could be trying to listen to something in a noisy environment or doing some visual task. The muscle memory developed from using two languages also can apply to different skills.

Q: Where are these benefits expressed in the brain?

A: First of all, we see increases in gray matter volume. The brain is made up of cells called neurons, which each have a cell body and little branching connections called dendrites. Gray matter refers to how many cell bodies and dendrites there are. Bilingual experience makes gray matter denser, so you have more cells. This is an indication of a healthier brain.

Bilingualism also affects white matter, a fatty substance that covers axons, which are the main projections coming out from neurons to connect them to other neurons. White matter allows messages to travel fast and efficiently across networks of nerves and to the brain. Bilingualism promotes the integrity of white matter as you age. It gives you more neurons to play with, and it strengthens or maintains the connections between them so that communication can happen optimally.

A bilingual brain can compensate for brain deterioration by using alternative brain networks and connections when original pathways have been destroyed.

Q: Does a bilingual brain age differently than a monolingual one?

A: We know from studies that starting at the age of about 25, your brain starts to decline, in terms of working memory, efficiency, processing speed, those kinds of things. As you age, these declines become steeper. The argument is that as we get into older age, bilingualism puts the brakes on and makes that decline less steep. Evidence from older adults is the strongest kind supporting a bilingual advantage. (The second strongest comes from children.)

When you look at bilingual individuals who have suffered neurodegeneration, their brains look damaged. From their brain scans, you’d think these people should be more forgetful, or that they shouldn’t be coping as well as they are. But that’s not the case. A bilingual brain can compensate for brain deterioration by using alternative brain networks and connections when original pathways have been destroyed. Researchers call this theory “cognitive compensation” and conclude that it occurs because bilingualism promotes the health of both gray and white matter.

Q: Could learning a language later in life keep Alzheimer’s at bay?

A: That is a working hypothesis. We’re doing studies where we teach a foreign language to people ages 65 and up with the goal of promoting healthy brain function, even at such a late point in life. What we’re testing is: Can we help people in old age by using language-learning? Does that give you some benefit in terms of a “use it or lose it” approach to brain health?

The initial signs are encouraging. Preliminary data look good. It seems that learning a language in later life results in positive cognitive outcomes.

Because language-learning and use is so complex—arguably the most complex behavior we human beings engage in—it involves many levels. You have speech sounds, syllables, words, grammar, sentences, syntax. There’s so much going on; it really is a workout for a wide brain network. And those areas of the brain overlap with the ones in which aging adult brains show decline or neurological pathological disease. As a result, we argue that learning a second language would be an optimal activity to promote healthy aging.

Q: What advice do you have for parents raising bilingual children?

A: To be encouraging and patient. Bilingual children have a tougher task than those learning only a single language. They’re learning two sets of vocabulary and speech sounds. It can be challenging for those of us living in a country with a dominant language to establish a functional purpose for the second language. A child needs to feel that the language is practical and has a use. Grandparents are great for this, and so is living in a community where there are cultural events or schools where children can be immersed in the second language.

Another concern parents bring up is worrying that their child might be mixing the languages. Don’t worry about what we refer to as “code mixing.” It’s a perfectly normal part of bilingual development. They’re not confused. It’s thought to be a sign of bilingual proficiency or competence to mix up the languages.

This article was adapted from a Washington Post article by Ramin Skibba.