Knowing 2 Languages Protects Your Brain From Stroke Damage

It turns out that being bilingual affects your ability to recover from a stroke- but not in the ways that most of us would expect. One of the prevailing myths about people who speak more than one language is that after a stroke, people lose the second language and can still communicate using the first language. But, surprisingly that isn't what usually happens. Not all strokes affect language function because the language centers of the brain are located in a relatively small region of the dominant side of the brain (the side of the brain opposite your dominant hand.) Even when a stroke affects the language area, there isn't a consistent 'first language' vs. 'second language' pattern.

What actually happens is that bilingual stroke survivors have better overall thinking and problem solving abilities after a stroke than stroke survivors who spoke one language prior to the stroke. 

What is bilingualism?

Some people who are bilingual have one primary language that was acquired because that is what their parents spoke at home prior to the age of 5 and another second language they learned in school, or even later in life. Some people who are bilingual communicated with one language that was regularly spoken at home and another language in the community. There are fewer people who are bilingual who learned more than one language at home at a very young age without having to 'learn' a second language. But there are numerous reasons for bilingualism and so many different individual life stories that explain why people know more than one language. Mark Zuckerberg, for example, decided to learn Chinese as an adult and became fluent in the language.

How does bilingualism affect your brain?

It turns out that people who are bilingual develop dementia 4-5 years later than people who can only speak one language. Neuroscientists have evaluated the brains of people who are bilingual by using brain imaging studies and compared them to people who spoke one language.

It turned out that people who are bilingual actually have larger brains. Normal aging results in about 1% brain loss every year, but the brain loss of people who are bilingual is significantly slower than the brain loss of the rest of the population. This brain ‘reserve’ is what neuroscientists believe may protect the cognitive abilities of people who are bilingual as they age. 

The specific area that was noted to be larger in bilingual individuals is the region of the brain called the grey matter. The grey matter of the brain is what we use for solving challenging problems and for understanding complex concepts. Learning a second language and using more than one language entails high level thinking that involves areas of the grey matter beyond the language region. 

Bilingual stroke survivors 

This 'brain reserve' or 'spare brain' seems to come in handy when someone has a stroke. A recent experiment published in the journal Stroke compared bilingual stroke survivors to monolingual stroke survivors on tests of cognitive ability.

It turned out that 40.5% of bilingual stroke survivors had normal cognitive abilities while only 19.6% of monolingual stroke survivors had normal cognitive abilities. Authors of the study suggested that the explanation for this large difference was probably due to the brain reserve that is developed in bilingualism. 

Protecting your brain

There are other ways to build ‘brain reserve’ besides learning a second language. Find out more about building spare brain here. Protecting yourself from head trauma is also an important way to keep your brain healthy and to protect against stroke damage. And recovery after a stroke may be enhanced by unexpected lifestyle factors such as spirituality.



Impact of Bilingualism on Cognitive Outcome After Stroke, Alladi S, Bak THMekala S, Rajan A, Chaudhuri JR, Mioshi E, Krovvidi R, Surampudi B, Duggirala V, Kaul S, Stroke, January 2016


Bilingualism provides a neural reserve for aging populations, Abutalebi J, Guidi L, Borsa V, Canini M, Della Rosa PA, Parris BA, Weekes BS, Neuropsycholgia, March 2015

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