Brain 'Asymmetry' Works for Reading Skills
Extra space on left side of brain may boost language skills, study suggests
SATURDAY, Nov. 17, 2001 (HealthDayNews) -- Asymmetry may suggest an imperfection or misalignment, but when it comes to the right and left sides of the brain, the variations appear to have an important role in children's reading and verbal skills.
Language and reading abilities are known to be associated with the left side of the brain, and, as seen in many matching parts of the body, a natural asymmetry is normal, with the left side being slightly larger.
According to a new study, that extra space may pay off in language abilities.
The study, published in a recent issue of the journal Child Development, found that children with greater symmetry between the two sides of the brain don't perform as well on reading-skill tests as those with the more-common asymmetry between the two sides.
The finding was based on study of 39 sixth-graders in Florida. The children were given magnetic resonance imaging (MRI) scans, then tested for a variety of reading abilities, including pronouncing unfamiliar words, determining missing words in a paragraph and reordering nonsense syllables into words.
The researchers found that children whose MRIs showed more symmetry between right and left sides of the brain didn't do as well on the tests as those who displayed asymmetry.
In addition to examining the MRIs and the tests, the researchers also considered the socio-economic status of the students, because children from low-income families often have poor reading and verbal skills.
Although kids from low-income families did indeed perform more poorly on the reading tests and low-income kids who had little asymmetry showed the weakest mastery of language, overall the kids with less brain asymmetry had consistently lower reading scores, regardless of income levels.
And those from lower income families had no greater levels of brain symmetry than children from other income levels.
"There were two main findings," says lead study author Mark A. Eckert, an instructor in the department neuroscience at the University of Florida's McKnight Brain Institute. "One is that brain asymmetry predicted the children's verbal ability, and the other was that it was true in both economic groups."
Eckert speculates that because the language facilities are known to reside, for the most part, in the left side of the brain, those who have more symmetrical brains, and hence smaller left sides, may be at a language disadvantage.
"It may be that if you have this reversed asymmetry, your language isn't completely lateralized to the left hemisphere and you might not be as good at processing oral language as other people," he says.
Interestingly, the researchers also found that the correlation between reading ability and brain asymmetry only applied to right-handed participants. Eckert says the patterns were not as clear in left-handed people.
"In our studies, we frequently see relations between the asymmetry and verbal ability of right-handers, but that relationship is sporadic in left-handers" he says.
Eckert says that before brain symmetry is even considered as a factor to look at in children with learning problems, research must be done to find out what kinds of intervention could help these children.
Child development expert Dr. Jean Berko Gleason, a professor of psychology at Boston University, says that regardless of the size or shape of a child's brain, early intervention can almost always help with reading and verbal skills.
"I don't think you can draw the conclusion that you're predestined to be a good or bad reader, because it's conceivable that early language experience can indeed contribute to the development of your brain," she says.
"If people are reading to you and talking to you, and you have a lot of linguistic experience from your earliest years, there's no reason not to assume that your brain wouldn't develop to represent the experiences you have."
Early experiences of being regularly read to and spoken to can have a powerful impact on not only reading skills later in life, but even on the physical development of the brain, Gleason adds.
"You have a period in early development where there is an enormous proliferation of neurons in the brain and then there is a pruning of those neurons to represent what your experiences have been," Gleason explains.
Those experiences profoundly shape the development of the brain, regardless of the amount of asymmetry between left and right sides, she adds.
What to Do: Visit the National Education Association's Web page on "How Can I Help My Child Learn How To Read?" for tips on developing reading skills. And here's an educational site on child brain development, offered by the National Network for Child Care.