Brain scan predicts dyslexia gains

About 20% of dyslexic children will improve their reading abilities by the time they become adults, and a new study shows how brain scans can predict who they are.

Brain imaging can foretell which dyslexic children will improve their reading skills over time.

Dyslexics don’t necessarily write letters out of order. But they do have a reading impairment that affects 5 to 17% of children in the US. About one-fifth of dyslexic children will improve their reading skills by the time they become adults – but improvements in reading ability are hard to predict.

So Fumiko Hoeft from Stanford and her colleagues recruited 25 children with dyslexia and 20 without. The team evaluated their reading skills with standardized tests and scanned their brains using functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI).

Two and a half years later, the researchers reevaluated the adolescents, looking for any indication in their brain scans or paper-and-pencil test results that could be correlated with improved reading.

They found that the standardized tests failed to predict future reading improvements, but the brain imaging did.

More reading improvement was seen in dyslexics with greater activity and structural connectivity in the brain’s right hemisphere (pictured).

"This gives us hope that we can identify which children might get better over time,” says Hoeft. “More study is needed before the technique is clinically useful, but this is a huge step forward."

Hoeft suggests that youths with dyslexia recruited right brain frontal regions to compensate for their reading difficulties, rather than regions in the left side of their brains, as typical readers do.

A test could one day predict which dyslexic individuals would most likely benefit from specific treatments, the findings suggest.

"It is the hope that we can identify children who will later develop dyslexia much earlier and more accurately," Hoeft says, "so we can provide necessary interventions ASAP."

This study provides a simple answer to the complex question: 'what can neuroscience contribute to complex issues in education?' co-author Bruce McCandliss says. "Here we have a clear example of how new insights and discoveries are beginning to emerge by pairing rigorous education research with novel neuroimaging approaches."

Partly funded by the National Institutes of Health, this study was published in Proceedings of the National Academy of Sciences yesterday.

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