MONDAY, Jan. 23 (HealthDay News) -- New imaging research shows that the reduced brain activity associated with the onset of dyslexia appears to develop before, not after, a child starts to read.
Key parts of the brain's rear left hemisphere critical to language processing do not undergo activity changes as a consequence of dyslexia, the study suggests, but may instead be part of the cause.
The finding could ultimately help clinicians screen for at-risk children at an early pre-reading age, when interventions to reduce the severity of the condition might be most effective.
"We already knew that children and adults with a diagnosis of dyslexia show brain alterations within the left posterior -- back -- part of the brain," said study co-author Nadine Gaab, an assistant professor of pediatrics in the neuroscience program at Harvard Medical School and Children's Hospital Boston. "However, it was unclear whether these alterations are a result of dyslexia [that] show up after years of reading failure or whether they predate the reading onset," she noted.
"[Here] we could show that they predate reading onset," Gaab said. "This suggests that children are either born with it or that it develops within the first few years of life."
The study, published in the Jan. 23 issue of the Proceedings of the National Academy of Sciences, focused on 36 healthy kindergarteners aged 5 and 6 years who had not begun to read.
Half of the children were at a high risk for developing dyslexia, as at least one of their immediate family members had been previously diagnosed with the disability. None of the children had difficulty with hearing or vision, and none had a history of either neurological or psychological illness.
After completing standard pre-reading language and vocabulary skills assessments, all of the children participated in a couple of audio-identification tasks.
All rights reserved