Brain anatomy differences between deaf, hearing depend on first language learned

April 15, 2014
brain
MRI brain scan

In the first known study of its kind, researchers have shown that the language we learn as children affects brain structure, as does hearing status. The findings are reported in the Journal of Neuroscience.

While research has shown that people who are and hearing differ in , these studies have been limited to studies of individuals who are deaf and use American Sign Language (ASL) from birth. But 95 percent of the deaf population in America is born to hearing parents and use English or another spoken as their first language, usually through lip-reading. Since both language and audition are housed in nearby locations in the , understanding which differences are attributed to hearing and which to language is critical in understanding the mechanisms by which experience shapes the brain.

"What we've learned to date about differences in brain anatomy in hearing and deaf populations hasn't taken into account the diverse language experiences among people who are deaf," says senior author Guinevere Eden, D.Phil., director for the Center for the Study of Learning at Georgetown University Medical Center (GUMC).

Eden and her colleagues report on a new structural brain imaging study that shows, in addition to deafness, early language experience – English versus ASL – impacts . Half of the adult hearing and half of the deaf participants in the study had learned ASL as children from their deaf parents, while the other half had grown up using English with their hearing parents.

"We found that our deaf and hearing participants, irrespective of language experience, differed in the volume of brain white matter in their auditory cortex. But, we also found differences in left hemisphere language areas, and these differences were specific to those whose native language was ASL," Eden explains.

The research team, which includes Daniel S. Koo, PhD, and Carol J. LaSasso, PhD, of Gallaudet University in Washington, say their findings should impact studies of brain differences in deaf and hearing people going forward.

"Prior research studies comparing brain structure in individuals who are deaf and attempted to control for language experience by only focusing on those who grew up using sign language," explains Olumide Olulade, PhD, the study's lead author and post-doctoral fellow at GUMC. "However, restricting the investigation to a small minority of the deaf population means the results can't be applied to all ."

Explore further: Deaf sign language users pick up faster on body language

Related Stories

Deaf sign language users pick up faster on body language

January 12, 2012
Deaf people who use sign language are quicker at recognizing and interpreting body language than hearing non-signers, according to new research from investigators at UC Davis and UC Irvine.

Program taught in American Sign Language helps deaf achieve healthier weight

March 19, 2014
A group of deaf adults using American Sign Language in a healthy lifestyle program successfully lost weight, according to a study presented at the American Heart Association's Epidemiology & Prevention/Nutrition, Physical ...

Early exposure to language for deaf children

June 5, 2012
(Medical Xpress) -- Most agree that the earlier you expose a child to a language, the easier it is for that child to pick it up. The same rules apply for deaf children.

A window on how language develops

March 28, 2014
Linguists have long debated what aspects of language are transmitted through culture and what aspects must be hard-wired into our brains. But it's impossible to take away the culture and study language development in isolation: ...

Need for culturally sensitive treatment for deaf patients with psychiatric disorders

March 11, 2013
Members of the Deaf community who suffer from mental health problems need culturally sensitive treatment to avoid misdiagnosis and inappropriate treatment, according to a report in the March Journal of Psychiatric Practice.

Recommended for you

Many kinds of happiness promote better health, study finds

July 21, 2017
A new study links the capacity to feel a variety of upbeat emotions to better health.

Study examines effects of stopping psychiatric medication

July 20, 2017
Despite numerous obstacles and severe withdrawal effects, long-term users of psychiatric drugs can stop taking them if they choose, and mental health care professionals could be more helpful to such individuals, according ...

Study finds gene variant increases risk for depression

July 20, 2017
A University of Central Florida study has found that a gene variant, thought to be carried by nearly 25 percent of the population, increases the odds of developing depression.

In making decisions, are you an ant or a grasshopper?

July 20, 2017
In one of Aesop's famous fables, we are introduced to the grasshopper and the ant, whose decisions about how to spend their time affect their lives and future. The jovial grasshopper has a blast all summer singing and playing, ...

Perceiving oneself as less physically active than peers is linked to a shorter lifespan

July 20, 2017
Would you say that you are physically more active, less active, or about equally active as other people your age?

Old antibiotic could form new depression treatment

July 19, 2017
An antibiotic used mostly to treat acne has been found to improve the quality of life for people with major depression, in a world-first clinical trial conducted at Deakin University.

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.