June 2012

Bilingual Effects in the Brain

Scientists found that certain brain functions are enhanced in teens fluent in more than one language. The study gives clues to the interplay between our brains and senses.

About 1 in 5 children nationwide speaks a language other than English at home. Studies have found that children who speak 2 languages (bilingual) tend to be better than monolingual children at multitasking. They are also better at focusing their attention—for example, homing in on a voice in a noisy cafeteria.

To learn more, scientists at Northwestern University studied 48 high school students. All were skilled speakers of English; about half were also Spanish speakers.

The teens listened to speech syllables while scientists measured activity in specific brain circuits that process complex sounds. Bilinguals showed a stronger response than monolinguals. When the sound was played with a background of babble, bilinguals continued to have a strong response, but the response fell for monolingual teens.

Bilingual teens also outperformed monolingual teens on a test of selective attention, in which they were asked to repeatedly click a mouse when a 1, but not a 2, was seen or heard. Among bilingual teens, scores on this test matched up with the intensity of their brain circuit responses to the babble test.

“Bilingualism serves as enrichment for the brain and has real consequences when it comes to executive function, specifically attention and working memory,” says Dr. Nina Kraus, lead researcher of the study. In future efforts, the team plans to explore whether similar benefits can be achieved by learning a language later in life.