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Developmental dyslexia affects 5 to 17 percent of children, often causing lasting frustration. Statistics show that children with reading problems are more apt to drop out of school and enter the juvenile justice system. But research in Children's Laboratories of Cognitive Neuroscience suggests that much frustration could be avoided by spotting children at risk for dyslexia and intervening as early as age 4—before reading instruction begins.
"Currently, dyslexia can only be diagnosed in second or third grade," says senior investigator Nadine Gaab, PhD. "In my opinion, that's way too late."
In 2007, Gaab and colleagues demonstrated that school-age children with dyslexia have functional differences in their brains that can be reversed—and their reading improved—with computer games that train them to detect subtle differences in sounds. Now, they are studying 4- to 6-year-olds with a family history of dyslexia, and finding some of the same brain differences in pre-readers.
Compared with controls, children with dyslexia in their family had structural alterations in several brain regions, correlating with poorer performance on pre-reading skills such as manipulating the sounds of language (saying "cat" without the "c," for example). On functional MRI (fMRI) studies—among the first ever done on young children—they showed altered activation in a variety of brain regions when trying to distinguish between rapidly presented sounds or when deciding whether two words start with the same sound.
Josh Thibeau, whose three older siblings have varying degrees of dyslexia, entered the study last year after completing kindergarten. "We noticed he was having a hard time recognizing his letters," says his mother, Janet. "He was at a point where we would be able to get some feedback from their assessment." She thinks the study will also help educators. "Some teachers have very good intentions, but not a clear understanding of what interventions are needed," she says. "The more we can educate teachers, the better the experience our children will have in school."
Gaab's team is studying a second group of pre-readers this year, to confirm its findings, add optional genetic testing and examine brain patterns, seeking the best dyslexia predictor. "We also want to document how typical reading develops in the brain," says Gaab.
The team has developed an elaborate protocol to coax young children to lie still in the fMRI scanner. For information on enrolling, email nora.raschle@childrens.harvard.edu.
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