People who speak more than one language fluently process information more easily than those who know only one language, a new study shows.
Researcher Viorica Marian, of Northwestern University's School of Communication, explains that is because the bilingual brain is constantly choosing which language to use and which to ignore.
Marian proposed this concept, which she calls co-activation, in 1999. Her new study, published in the journal Brain and Language, used functional magnetic resonance imaging to test its validity. Volunteers performed word recognition exercises. By watching blood flow as they did the tasks - a measure of how hard the brain was working - Marian found that monolinguals had to work harder to identify the correct words.
The brains of bilingual speakers are more efficient, she reports, because they are better at inhibitory control, constantly filtering out irrelevant words.
"Using another language," she said, "provides the brain built-in exercise."
That may help explain why bilingualism seems to help forestall Alzheimer's and dementia, she says. Other studies suggest that bilingual children are better at filtering out classroom noise than children who speak only one language.
