December 21, 2010

Brain Scans Help Predict Future Reading Success In Dyslexics


By searching for a specific pattern of brain activity in teens with dyslexia, the researchers were able to predict with 90 percent accuracy which students would learn to read.

"This gives us hope that we can identify which children might get better over time," Dr. Fumiko Hoeft of Stanford University School of Medicine, said in a statement.

"More study is needed before the technique is clinically useful, but this is a huge step forward," Hoeft said, whose study appears in the Proceedings of the National Academy of Sciences.

Dyslexia is a brain-based learning disability that affects between 5 and 17 percent of US children. People with dyslexia have difficulties with concentrating, reading, spelling, writing and pronouncing words.

Roughly one-fifth of those with severe dyslexia do learn to read. Hoeft and colleagues wanted to see what was occurring in the brains in these students.

They studied 45 teens between the ages of 11 and 14 who took a series of tests to determine their reading level. Based on those tests, they were able to classify 25 of them as dyslexics.

The researchers used two different imaging techniques: functional magnetic resonance imaging (MRI), which measures oxygen used by the brain during different activities, and diffusion tensor magnetic resonance imaging or DTI, which reveals connections between brain areas.

The team then showed the teens different pairs of words and asked them to identify which ones rhymed, even though they were spelled differently.

They found that about 50 percent of the teens with dyslexia had extra activity in a part of the brain near the right temple known as the right inferior frontal gyrus. And some of the children with dyslexia had stronger connections in a network of brain fibers that links the front of the brain to the back.

When the scientists checked these same teens 30 months later, they discovered children who had this unusual brain activity were more likely to have learned to read than other dyslexics.

Paper and pencil tests typically used for these children, however, were unable to predict which students would succeed.

"The reason this is exciting is that until now, there have been no known measures that predicted who will learn to compensate," Hoeft said.

Alan Guttmacher, director the National Institute of Child Health and Human Development said the finding gives insight into how certain people with dyslexia compensate for reading trouble.

"Learning why other individuals have difficulty compensating may lead to new treatments to help them overcome reading disability," Guttmacher, whose agency funded the study, said in a statement to Reuters.

The study is part of a new field called "educational neuroscience" that uses brain imaging studies to help improve learning problems in children and teens.


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