Being Bilingual Boosts Brain
Oct. 13, 2004
People who are bilingual have an advantage over the rest of us, and not just in
terms of communication skills. The bilingual brain develops more densely, giving
it an advantage in various abilities and skills, according to new research.
Researchers Andrea Mechelli of London's Wellcome Department of Imaging
Neuroscience and colleagues, including experts from the Fondazione Santa
Lucia in Rome, looked at brain densities of bilingual people.
First, they recruited 25 people who speak one language, 25 who learned a
second European language before age 5, and 33 who became bilingual between ages
10 and 15.
All the participants spoke English as their primary language. Those who had
learned a second language later in life had practiced it regularly for at
least five years.
Bilingual Brains Do Better
The brain has two types of tissue visible to the naked eye, termed gray and
white matter. Gray matter makes up the bulk of nerve cells within the brain.
Studies have shown an association with gray matter density (or volume and
intellect), especially in areas of language, memory, and attention.
Brain imaging showed that bilingual speakers had denser gray matter compared
with monolingual participants.
The difference was especially significant in the brain's left side —an area
known to control language and communication skills. The right hemisphere of
bilingual speakers also showed a similar trend.
The researchers say that although language is thought to be mediated by
functional changes in the brain, they show that being bilingual structurally
changes the brain. Their study shows the effect was strongest in people who
had learned a second language before age 5.
In a second test, the researchers studied 22 native Italian speakers who had
learned English as a second language between ages 2 and 34.
Those who had learned English at a young age had greater proficiency in
reading, writing, talking, and understanding English speech.
As in the first test, increases in gray matter density in the brain's left
region were linked to age at which a person became bilingual. The earliest
second language learners had the densest gray matter in that part of the brain.
Of course, while it might seem easier to pick up a second language as a
child, it's still possible to do so as an adult.
"Our findings suggest that the structure of the human brain is altered by the
experience of acquiring a second language," write the researchers in the October
issue of the journal Nature.
SOURCE: Mechelli, A. Nature, October 2004; vol 431: p 757.