The ability to communicate in multiple languages not only provides doorways to new cultural and social experiences but also apparently promotes brain growth and staves off the onset of dementia and Alzheimer’s disease.

Researchers at the University of Kentucky and Kyungpook National University in South Korea studied 110 participants (who were either bilingual or monolingual) while undergoing functional magnetic resonance imaging (fMRI). The results of the experiments showed that older adult bilinguals “showed better perceptual switching performance than their monolingual peers” and that older adult bilinguals required less blood flow to the frontal cortex and cingulate cortex in order to complete certain mental tasks.

The study suggests that “lifelong bilingualism offsets age-related declines in the neural efficiency for cognitive control processes.” In other words, as the brain ages, it inevitably becomes less able to conduct the thought processes involved in everyday life.  According to the study, being bilingual throughout life helps delay this slowdown.

Other studies, such as the one conducted at the University of Toronto, have shown that bilingualism significantly improves white matter integrity and thickening of the cerebral cortex. White matter relays communications between various parts of the brain, and its deterioration results in decreased cognitive speed and acuity. The cerebral cortex is the layer covering the outer part of the cerebrum and is often referred to as gray matter. It is here where most information processing takes place in the brain.

Bilingualism has been regarded by some as a hindrance to a child’s intellectual development. Although there is plenty of data to show that bilingual brains keep both language systems active even when speaking or reading in just one, this is less of a drawback than was once believed. In fact, it conditions the brain to resolve the internal conflict between the languages, thereby strengthening its cognitive abilities.

A 2004 study on monolingual and bilingual (French and English) children found that the bilingual children were quicker at performing mental tasks such as sorting objects on a computer screen by color and shape. Other studies have reinforced the collective evidence that bilingualism improves the brain’s ability to plan, solve problems and perform mentally challenging tasks. It also improves the ability to ignore distractions, hold information in mind, and switch attention from one important task to the other.

In essence, a bilingual brain “exercises” the abilities that help keep it young: concentration, memorization, rapid purposeful switching, and flexibility. Although the benefits are greatest for those with lifelong experience in multiple languages, it is never too late to start learning a new way of talking and thinking.

References

Gold BT, Kim C, Johnson NF, Kryscio RJ, & Smith CD (2013). Lifelong bilingualism maintains neural efficiency for cognitive control in aging. The Journal of neuroscience : the official journal of the Society for Neuroscience, 33 (2), 387-96 PMID: 23303919

Luk G, Bialystok E, Craik FI, & Grady CL (2011). Lifelong bilingualism maintains white matter integrity in older adults. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31 (46), 16808-13 PMID: 22090506

Bialystok E, & Martin MM (2004). Attention and inhibition in bilingual children: evidence from the dimensional change card sort task. Developmental science, 7 (3), 325-39 PMID: 15595373

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