bilingual brains
November 14, 2014

Speaking Multiple Languages Routinely Exercises Your Brain

Eric Hopton for redOrbit.com - Your Universe Online

Never mind the Chess or Sudoku: learn another language to give your brain a kick.

Bilingual speakers process information more efficiently and more easily than those who only speak a single language, and a new study by scientists at Northwestern University tells us that speaking more than one language is also good for the brain.

The University's Viorica Marian is lead author of the research and a professor in the department of communication sciences and disorders in the School of Communication. She believes that the benefits occur because the bilingual brain is constantly activating both languages and choosing which language to use and which to ignore. When the brain is constantly being exercised in this way, it has to work less hard to perform cognitive tasks.

“It's like a stop light,” Marian said. “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.”

The study, published online in the journal Brain and Language, is one of the first to use fMRI (functional magnetic resonance imaging) to test co-activation and inhibition in bilinguals. In 1999, Marian pioneered the concept of “co-activation during bilingual spoken language comprehension.” This established that, in the brains of people who are fluent bilinguals, both languages are “active” at the same time even if the individual is not conscious of this “double-language” function. When faced with selecting the correct language from a competing language, the brain uses an inhibitory control mechanism.

In previous research, Marian recorded eye movements to track co-activation and the inhibitory control function. This showed that when bilinguals heard words in one language, for example “marker” in English, they often made eye movements to objects whose names sounded similar in another language they knew, such as “marka”, the Russian word for stamp.

The latest research makes use of more sophisticated MRI imaging. The fMRI scans reveal changes in blood flow to specific brain areas when volunteers perform a cognitive task. Increased oxygen or blood flow to the region means that part of the brain is working harder.

Research subjects performed language comprehension tasks. After hearing a word, the participants were shown pictures of four objects. For example, after hearing the word “cloud” they would be shown four pictures, including a picture of a cloud and a picture of a similar-sounding word, such as a “clown.” The study participants needed to recognize the correct word and ignore the similar-sounding competing word. Bilingual speakers were much more adept at filtering out the incorrect words. This is due to the fact that, in their everyday lives, their brains are constantly controlling two languages and inhibiting irrelevant words.

“Monolinguals had more activation in the inhibitory control regions than bilinguals; they had to work much harder to perform the task,” said Marian.

The benefits of more efficient “bilingual” brains extend well beyond the use of multiple languages. For example, Marian recently found, in research co-authored with colleagues in the U.K. and published last month in the journal Bilingualism: Language and Cognition, that bilingual children were better at ignoring classroom noise.

“Inhibitory control is a hallmark of cognition” said Marian. “Whether we're driving or performing surgery, it's important to focus on what really matters and ignore what doesn't.” This mechanism may also help explain why bilingualism is thought to offer some protection against Alzheimer's and dementia.

Marian believes that this is the “exciting part.”

“Using another language provides the brain built-in exercise. You don't have to go out of your way to do a puzzle because the brain is already constantly juggling two languages,” she explained.

Marian's team included Northwestern Ph.D candidates Sarah Chabal and James Bartolotti. They collaborated with Kailyn Bradley and Arturo Hernandez of the University of Houston.

Marian grew up speaking both Romanian and Russian. Her third language is English and she also speaks some basic Spanish, French and Dutch.

The Huffington Post recently reported that, according to François Grosjean, author of Bilingual: Life and Reality, most of the world’s population is bilingual. Grosjean estimates that 56 percent of Europeans, 38 percent of Brits, and 35 percent of Canadians speak more than one language at a generally proficient level. The situation is very different in the United States where less than one in five people are fluent in more than one language.

But Marian and her team believe that it's never too late to learn another language, however basic that learning might be. “The benefits can be seen even after just one semester of studying.”

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