Want to protect your brain from aging? Learn another language

Scientists have been finding out that there are methods that can slow down the aging of the brain, including learning another language. This was confirmed in a recent study by scientists at the HSE University (Russia) and Northumbria University (UK).

Cognitive Reserve

Central to the new research has been the idea of Cognitive Reserve (CR). As the scientists explain in their paper, published in Frontiers in Psychology, Cognitive Reserve, which consists of neural networks built up over a person’s lifetime, “is the individual ability to compensate for age-related neural deterioration and maintain optimal cognitive functioning.”

By affecting and training the cognitive reserve, we may influence the various skills that may otherwise start declining: overall information-processing speed, short-term and episodic memory, language ability, and executive and visuospatial functions.

When confronted with external stimuli, the brain makes neural networks stronger. Training the networks involved in the CR means making them more complex and preparing them to withstand the changes that old age will bring. Previous studies pointed to lifestyle factors, including physical exercise, proper nutrition, career changes, leisure habits, level of education, socio-economic status, and others as being key to improving your cognitive reserve.

The new study

Scientists have been consistently adding another important element into the brain-health mix — being bilingual. In a new experimental study involving 63 healthy adults above the age of 60, the participants were required to have at least some knowledge of a second language.

Prior to the experiment, all the subjects took a questionnaire that tried to assess their cognitive reserve based on questions about their social life, education, profession, sports, and more. They also had to specify their fluency in a second language and how long they had known it.

The experiment had the participants perform a “flanker task” to test inhibitory executive control. The task had the participants choosing the direction of the central arrow in a row of five arrows, where the arrows were pointing in various directions. As they had to do this quickly, it presented a challenge since it’s been found that when the central arrow and the side arrows point in diverging directions, the subject has a harder time getting the answer correctly. What the researchers found, however, was that people who studied a second language performed better at this task in proportion to how fluent they were in the language. The greater their language skills, the better they did!

Researchers believe the explanation for this prowess on the part of bilingual speakers lies in the fact that they often face similar situations in everyday life, having to choose between two systems of language.

Why bilingualism helps the brain

Federico Gallo, one of the study authors of the HSE University Institute of Cognitive Neuroscience, explained why this works — “Unlike other factors that shape cognitive reserve, bilingualism is unique in that it is constantly present in our lives.” It’s not something you just turn off or choose to do or not to do on a certain day, like going to the gym or being on a diet. Language is always engaged whether we talk, watch movies or read books.

“We witnessed an interesting phenomenon in this experiment: with a high level of language proficiency, the correlation between successful conflict resolution and other components of cognitive reserve disappeared,” shared Gallo. “This suggests that bilingualism's benefits on cognitive reserve might be stronger than those of other known factors."

What’s more, the scientists also discovered that being able to speak in two or more languages doesn’t only help healthy brains but also improves the functioning of those with neurodegenerative disorders like dementia, Alzheimer's, Parkinson's disease, or those who’ve had a stroke. Gallo also shared the data demonstrating that active bilingual speakers tend to be diagnosed with neurodegenerative diseases 5–7 years later than speakers of only one language. 

Considering the current absence of effective-enough drugs that can prevent brain aging, Gallo recommends that “non-drug ways to slow down cognitive aging should become a priority in science.”

Growing body of evidence

Gallo’s work builds on a growing body of research that highlights the importance of learning languages for our brains. A 2020 study by York University psychology researchers found evidence that bilingualism could delay symptoms of dementia. Bilinguals could function at a high level even as the disease was spreading through their brain, showing greater resilience in dealing with neurodegeneration. As the authors pointed out, the bilinguals were operating at a higher level of functioning because of their cognitive reserve.

The study’s lead author Ellen Bialystok, Professor in York's Department of Psychology, shared that "Given that there is no effective treatment for Alzheimer's or dementia, the very best you can hope for is keeping these people functioning so that they live independently so that they don't lose connection with family and friends. That's huge."

Another 2020 study from Singapore, published in the Journals of Gerontology: Psychological Sciences, also discovered the positive benefits of bilingualism. Carried out by researchers from the Singapore University of Technology and Design (SUTD), the study showed how the regular use of two languages and language switching could help protect the brain against the effects of aging. They focused on how a group of healthy seniors from 60 to 84 years old, who were fluent in Chinese and English, performed certain computerized control tasks, which involved executive functions, which are the brain’s complex, higher-order processes. These functions help us stay focused on tasks and not distracted by irrelevant information.

The subjects actively using two languages “with less frequent language switching” performed better in following their goals and “conflict monitoring”.

The author, Associate Professor Yow Wei Quin from SUTD, explained, “The effort involved in not switching between languages and “staying” in the target language is more cognitively demanding than switching between languages while actively using both languages.” According to what they observed in their study, “seniors developed more efficient neural organization at brain regions related to language control, which also overlap with areas involved in executive control.”

As there have also been previous studies showing the benefits of bilingualism, perhaps it is time to consider learning another language.

Abstract:

Add Bilingualism to the Mix: L2 Proficiency Modulates the Effect of Cognitive Reserve Proxies on Executive Performance in Healthy Aging

HSE University / Northumbria University (2022)

Frontiers in Psychology

We investigated the contribution of bilingual experience to the development of cognitive reserve (CR) when compared with other, traditionally more researched, CR proxies, in a sample of cognitively healthy senior (60 +) bilingual speakers. Participants performed in an online study where, in addition to a wide inventory of factors known to promote CR, we assessed several factors related to their second language (L2) use. In addition, participants’ inhibitory executive control was measured via the Flanker Task. We used Structural Equation Modeling to derive a latent composite measure of CR informed by traditional CR proxies (i.e., occupational complexity, marital status, current and retrospective socio-economic status, physical exercise, perceived positive support, maximal educational attainment, frequency of leisure activities and extent of social network). We examined whether bilingualism may act as a mediator of the effects of such proxies on cognitive performance therefore assessing the unique contribution of dual language use to CR. First, our analyses revealed facilitatory effects of both L2 age of acquisition and L2 proficiency on the executive performance. Second, our analyses confirmed the moderating role of bilingual experience on the relationship between other factors known to promote CR and cognitive integrity, revealing a strong contribution by bilingualism to CR development. Our findings provide further support to the notion that bilingualism plays an important role in mitigating cognitive decline and promoting successful aging.