Fit brains, good health?

Bilingualism seems to protect against dementia, according to work done by psycholinguist

Ellen Bialystok at Canada’s York University where she compared monolinguals and bilinguals as they aged.

“The bilinguals showed symptoms of Alzheimer’s some four to five years after monolinguals with the same disease pathology,” she says.

Being bilingual didn’t prevent people from getting dementia, but it delayed its effects, a 2007 study published in the journal Neuropsychologia found. In two people whose brains showed similar levels of disease progression, the bilingual person would show symptoms an average of five years after the monolingual, says Bialystok, citing 2010 research in the journal Neurology.

She thinks this is because bilingualism rewires the brain and improves the executive system, boosting people’s “cognitive reserve”.

It means that, as parts of the brain succumb to damage, bilinguals can compensate more because they have extra grey matter and alternative neural pathways.

Speaking more than one language may also help patients to recover more quickly after brain injury, a study of 600 stroke survivors in India published in the journal Stroke suggests. In fact, cognitive recovery was twice as likely for bilinguals as for monolinguals.

Asteady stream of studies over the past decade has shown that bilinguals outperform monolinguals in a range of cognitive and social tasks from verbal and nonverbal tests to how well they can read other people, research published in the journal Trends in Cognitive Sciences shows. Greater empathy is thought to be because bilinguals are better at blocking out their own feelings and beliefs in order to concentrate on the other person’s.

In fact, it is possible to distinguish bilingual people from monolinguals simply by looking at scans of their brains, says cognitive neuropsychologist Jubin Abutalebi at the University of San Raffaele in Milan.

“Bilingual people have significantly more grey matter than monolinguals in their anterior cingulate cortex, and that is because they are using it so much more often,” he says. The ACC is like a cognitive muscle, he adds: the more you use it, the stronger, bigger and more flexible it gets.

Bilinguals, it turns out, exercise their executive control all the time because their two languages are constantly competing for attention. Brain-imaging studies show that, when a bilingual person is speaking in one language, their ACC is continually suppressing the urge to use words and grammar from their other language, a 2008 study published in the journal of Language and Cognitive Processes found.

Their mind is always making a judgment about when and how to