Bilingualism helps boost brain power and hearing

PUBLISHED : Tuesday, 01 May, 2012, 12:00am
UPDATED : Tuesday, 01 May, 2012, 12:00am

Nei ho, bonjour, konnichiwa, shalom, annyong, hello. Speaking more than one language not only breaks down communication barriers, but a new study has found biological evidence that bilingualism also improves hearing and enhances attention and working memory.

Published yesterday in the Proceedings of the National Academy of Sciences, the Northwestern University study zoomed in on the auditory regions beneath the brain's cortex that are bathed with input from cognitive brain areas. It was found that the experience of bilingualism changes how the nervous system responds to sound.

'People do crossword puzzles and other activities to keep their minds sharp,' says Viorica Marian, professor of communication sciences in Northwestern's School of Communication. 'But the advantages we've discovered in dual language speakers come automatically simply from knowing and using two languages. It seems that the benefits of bilingualism are particularly powerful and broad, and include attention, inhibition and encoding of sound.'

Nina Kraus, an auditory neuroscientist, adds: 'Bilingualism serves as enrichment for the brain and has real consequences when it comes to executive function, specifically attention and working memory.'

The researchers recorded the brainstem responses to complex sounds in 23 bilingual English- and Spanish-speaking teenagers and 25 English-only-speaking teens as they heard speech sounds in two conditions.

Under a quiet condition, the groups responded similarly. But against a backdrop of background noise, the bilingual brains were significantly better at processing sound and paying greater attention to relevant versus irrelevant sounds.

'Bilinguals are natural jugglers,' says Marian. 'Rather than promoting linguistic confusion, bilingualism promotes improved 'inhibitory control', or the ability to pick out relevant speech sounds and ignore others.'

In future studies, the researchers will investigate whether these results can be achieved by learning a language later in life.