Bilingualism fine-tunes hearing, enhances attention

April 30, 2012, Northwestern University

A Northwestern University study that will be published in the Proceedings of the National Academy of Sciences (PNAS) provides the first biological evidence that bilinguals' rich experience with language in essence "fine-tunes" their auditory nervous system and helps them juggle linguistic input in ways that enhance attention and working memory.

Northwestern expert Viorica Marian teamed up with auditory neuroscientist Nina Kraus to investigate how bilingualism affects the brain. In particular, they looked at subcortical auditory regions that are bathed with input from cognitive . In extensive research, Kraus has already shown that lifelong music training enhances language processing, and an examination of subcortical auditory regions helped to tell that tale.

"For our first collaborative study, we asked if bilingualism could also promote experience-dependent changes in the fundamental encoding of sound in the brainstem -- an evolutionarily ancient part of the brain," said Marian, professor of communication sciences in Northwestern's School of Communication. The answer, according to their study, is a resounding yes.

The researchers found that the experience of bilingualism changes how the nervous system responds to sound. "People do and other activities to keep their minds sharp," Marian said. "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."

Co-authored by Kraus, Marian and researchers Jennifer Krizman, Anthony Shook and Erika Skoe, "Bilingualism and the Brain: Subcortical Indices of Enhanced Executive Function" underscores the pervasive impact of bilingualism on . The article will appear in the April 30 issue of PNAS.

"Bilingualism serves as enrichment for the brain and has real consequences when it comes to executive function, specifically attention and ," said Kraus, Hugh Knowles Professor at Northwestern. In future studies, she and Marian will investigate whether these results can be achieved by learning a language later in life.

In the study, the researchers recorded the brainstem responses to complex sounds (cABR) 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 encoding the fundamental frequency of speech sounds known to underlie pitch perception and grouping of auditory objects. This enhancement was linked with advantages in auditory attention.

"Through experience-related tuning of attention, the bilingual auditory system becomes highly efficient in automatically processing sound," Kraus explained.

"Bilinguals are natural jugglers," said Marian. "The bilingual juggles linguistic input and, it appears, automatically pays greater attention to relevant versus irrelevant sounds. Rather than promoting linguistic confusion, bilingualism promotes improved 'inhibitory control,' or the ability to pick out relevant speech sounds and ignore others."

The study provides for system-wide neural plasticity in auditory experts that facilitates a tight coupling of sensory and cognitive functions. "The bilingual's enhanced experience with sound results in an auditory system that is highly efficient, flexible and focused in its automatic sound processing, especially in challenging or novel listening conditions," Kraus added.

Explore further: Neuroscientist: Think twice about cutting music in schools

Related Stories

Neuroscientist: Think twice about cutting music in schools

February 21, 2010
At a press briefing today at the American Association for the Advancement of Science annual meeting, a Northwestern University neuroscientist will argue that music training has profound effects that shape the sensory system ...

Musical aptitude relates to reading ability

October 17, 2011
Auditory working memory and attention, for example the ability to hear and then remember instructions while completing a task, are a necessary part of musical ability. But musical ability is also related to verbal memory ...

Musical experience offsets some aging effects

May 11, 2011
(Medical Xpress) -- A growing body of research finds musical training gives students learning advantages in the classroom. Now a Northwestern University study finds musical training can benefit Grandma, too, by offsetting ...

How noise and nervous system get in way of reading skills

July 13, 2009
A child's brain has to work overtime in a noisy classroom to do its typical but very important job of distinguishing sounds whose subtle differences are key to success with language and reading.

Study examines role of bilingualism in children's development

February 8, 2012
A new study on children who are raised bilingual examined the effects on children's development of growing up speaking two languages. The study found that different factors were responsible for the language- and non-language-related ...

New brain findings on dyslexic children

November 11, 2009
The vast majority of school-aged children can focus on the voice of a teacher amid the cacophony of the typical classroom thanks to a brain that automatically focuses on relevant, predictable and repeating auditory information, ...

Recommended for you

Study of protein 'trafficker' provides insight into autism and other brain disorders

September 22, 2018
In the brain, as in business, connections are everything. To maintain cellular associates, the outer surface of a neuron, its membrane, must express particular proteins—proverbial hands that reach out and greet nearby cells. ...

Breast milk may be best for premature babies' brain development

September 21, 2018
Babies born before their due date show better brain development when fed breast milk rather than formula, a study has found.

Early warning sign of psychosis detected

September 21, 2018
Brains of people at risk of psychosis exhibit a pattern that can help predict whether they will go on to develop full-fledged schizophrenia, a new Yale-led study shows. The findings could help doctors begin early intervention ...

White matter repair and traumatic brain injury

September 20, 2018
Traumatic brain injury (TBI) is a leading cause of death and disability in the U.S., contributing to about 30 percent of all injury deaths, according to the CDC. TBI causes damage to both white and gray matter in the brain, ...

Gut branches of vagus nerve essential components of brain's reward and motivation system

September 20, 2018
A novel gut-to-brain neural circuit establishes the vagus nerve as an essential component of the brain system that regulates reward and motivation, according to research conducted at the Icahn School of Medicine at Mount ...

Genomic dark matter activity connects Parkinson's and psychiatric diseases

September 20, 2018
Dopamine neurons are located in the midbrain, but their tendril-like axons can branch far into the higher cortical areas, influencing how we move and how we feel. New genetic evidence has revealed that these specialized cells ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.