For a groundbreaking 2010 study, a team of Canadian researchers explored the associations between bilingualism and Alzheimer’s disease.
At that time, it was known that socially and physically active older adults tended to enjoy a measure of protection from dementia, and the study team was interested to learn if the cognitive demands of bilingualism — the ability of speaking and understanding two or more languages — offered any similar protections.
To find out, they collected data on more than 200 people recently diagnosed with Alzheimer’s disease. They found that people who spoke two or more languages developed Alzheimer’s symptoms an average of five years later in life than those who spoke only one language. This time gap persisted even after the study team controlled for occupation, education level, country of birth, and other variables. (Later follow-up work has supported these findings.)
“The brain needs exercise just like the body, or it winnows away.”
How could bilingualism protect the brain from dementia? The study authors highlight something called “cognitive reserve,” which they describe as the capacity of the brain to maintain proper functioning despite the onslaught of disease. “[Bilingualism] appears to contribute to cognitive reserve, which acts to compensate for the effects of accumulated neuropathology,” they write.
The brain is an organ, not a muscle. But several decades of brain research have revealed that, much like a muscle, the brain appears to benefit from effortful training. Once a person reaches and surpasses middle age, that kind of training may be necessary to prevent the sort of weakening and wasting that, for different reasons, also threatens the muscles. “The brain needs exercise just like the body, or it winnows away,” says Catherine Caldwell-Harris, PhD, a bilingualism researcher and associate professor of psychological and brain sciences at Boston University. “The phrase use it or lose it — there’s a lot of neuroscience behind that.”
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Caldwell-Harris says that almost any novel activity — from taking up a new hobby to visiting a new place — seems to engage and challenge the brain in ways that can improve its functioning. But learning and using a second language may be the ultimate form of brain training. “Learning a new language is a type of all-demanding activity that involves almost all aspects of cognitive functioning,” she says. “It’s as complicated as chess or any science, but it also involves social interaction and activation and all of those processes.”
Language training not only seems to make the brain healthier and stronger, but it may also helpfully reshape the way its owner experiences and interacts with the world.
Bilingualism and the brain’s executive functions
The brain is not a static organ. It’s constantly changing in response to the tasks it performs. Many of those changes are measurable — both in terms of the brain’s electrical activity and in the actual mass and density of its cortical structures.
For a 2019 study in Frontiers in Neuroscience, Italian researchers measured the effects of language training on the brains of healthy older adults between 59 and 79. After just four months of studying English, the people in the study scored significantly better on two research-backed measures of brain health and acuity: tests of global cognition and functional connectivity.
“Learning a foreign language is one of the non-pharmacological cognitive interventions that can boost cognition in young and older adults,” says Giovanna Bubbico, PhD, first author of the study and a postdoctoral research at the University of California, Irvine and D’Annunzio University of Chieti–Pescara in Italy.
“The phrase use it or lose it — there’s a lot of neuroscience behind that.”
Unlike other novel activities — the cognitive benefits of which tend to fade once a person’s brain has gotten the hang of things — a second language never stops challenging the brain in helpful ways. “A second language forces the brain to switch between two languages — inhibiting one and favoring the other — depending on the context,” Bubbico says. The cerebral processes involved in this sort of context-monitoring and switching seems to beef up the brain’s executive functions, or its ability to plan, concentrate, make decisions, and engage in other important aspects of cognition, she explains.
Caldwell-Harris adds to this point. “Being cognitively flexible and able to switch from one task to the other, rather than staying in autopilot, is an important aspect of executive functioning,” she says.
People who have poor executive functioning — an issue that often emerges late in life, or in some cases following a brain injury — have a reduced ability to shift their thinking or behavior in response to changing circumstances. Basically, their brains become mired in old or unhelpful patterns of activity. “If you’re bilingual, you have to constantly be alert to what language is being spoken to you, which keeps alive this switching aspect,” she says. This may be one way in which bilingualism helps keep the brain agile and healthy.
At this point, Caldwell-Harris says that it’s not clear whether learning a second language during childhood or early adulthood is somehow better for the brain than tackling this challenge later in life. But she points out that much of the research on the benefits of bilingualism — such as the work showing its associations with delayed Alzheimer’s disease — have involved people who learned a second language at a young age.
Just as adopting a healthy diet or exercise routine early in life is surely better than doing so only in old age, it’s a good bet that challenging the brain with a second language while young will be better for the brain than doing so later on. And apart from making the brain sharper or more adept, there’s evidence that learning a second language can enrich the way people interact with others and with the world.
The concept of “linguistic relativity”
The Aymara, an indigenous people of South America, aren’t looking forward to 2021. That’s because, in their native language, the idea of “looking forward” to anything in the future would make no sense.
For a 2006 study in Cognitive Science, researchers documented the way the Aymara talk about time. While English speakers — and the speakers of most other languages — describe the future as something in front of them that they’re moving toward, the Aymara people talk about time from the opposite orientation. Since the future is unseeable, they reason, it must be behind them and out of sight. The past, which can be seen, therefore lies before them. The Aymara even gesture at their backs when talking about the future, the study team found.
“It’s as complicated as chess or any science, but it also involves social interaction and activation and all of those processes.”
This is just one example of how language can influence the way a speaker thinks about life and the world. This influence is known as linguistic relativity. Anyone who has ever studied a foreign language — whether Spanish or French or Chinese — has likely noticed how that language’s treatment of certain ideas or concepts may differ from one’s own.
“When you learn a foreign language, you learn that other people may think about things very differently than you do,” Caldwell-Harris says. “This experience can reveal new shades of meaning.”
She offers two more examples. The Russian language, unlike English, has two distinct words for the color blue — one referring to light blue shades and the other to dark blue shades. And research has found that, thanks to this linguistic distinction, Russians are quicker than English speakers at spotting differences among closely related shades of blue.
She also brings up the German word schadenfreude, which refers to the pleasure one may feel from another’s misfortune. While English speakers can understand this concept just as well as Germans, the fact that German speakers have a specific word for it likely strengthens their ability to identify and acknowledge this emotion in themselves or others.
Learning a new language confronts the brain with these sorts of unfamiliar, perspective-shifting insights. Basically, it takes what the brain thinks it understands and shakes it up, and this sort of shake-up is not only “mentally invigorating,” Caldwell-Harris says, but it can also help people see the world — and one another — in new and enriching ways.
She says that there are countless language learning tools online — many of which are free. Those are great places to get started. Once a person has some rudimentary knowledge, there are services that can connect learners with native speakers. (Search online for “language exchange” programs, which can pair you up with someone who speaks the language you’re studying and is also interested in learning your language. Most are inexpensive.)
“The problem with learning a foreign language is that people really just want the end result — to be fluent,” Caldwell-Harris adds. While fluency is an admirable goal, the real payoff for the brain begins as soon as a person starts learning. And it doesn’t stop.