Dr. Nadine Gaab of the Laboratory of Cognitive Neuroscience at Children's Hospital Boston says that the new finding may eventually translate into measures to diagnose dyslexia even before reading begins. She counts musical training among the possible new ways of treating dyslexia.
The researcher used functional MRI imaging (fMRI) examine how the brains of 9 to 12 year-old children with developmental dyslexia and that of normal readers responded to fast changing and slow changing sounds, which the participants were made to listen through headphones.
She also involved educational software called 'Fast ForWord Language', designed in part by a co-author on the study named Tallal, in her study.
In typical readers, 11 brain areas became more active when the children listened to fast-changing sounds, compared to slow-changing sounds.
In dyslexic children, the fast-changing sounds did not trigger this ramped-up brain activity. Their brains rather processed the fast-changing sounds as if they were slow-changing sounds.
"This is obviously wrong. Children with developmental dyslexia may be living in a world with in-between sounds. It could be that whenever I tell a dyslexic child 'ga,' they hear a mix of 'ga,' 'ka,' 'ba,' and 'wa'," says Dr. Gaab.
However, dyslexic children's brains changed after completing exercises in the computer program 'Fast ForWord Language', which involved listening to sounds, starting with simple, changing noises, like chirps that swooped up in pitch. The children then had to indicate whether the chirp's pitch went up or down.
The researchers later introduced increasingly complex sounds like syllables, words, and sentences in the exercises.
After eight weeks of daily sessions, about 60 hours total, dyslexic children's brains started responding more like typical readers' when processing fast-changing sounds. It also helped improve their reading ability.
The researchers, however, are unclear whether the improvement would have lasted beyond a few weeks, as they did not conduct follow-up tests.
Dr. Gaab is now planning to investigate whether other type of sound trainingósuch as learning to sing or play a musical instrumentómay help dyslexic children.
"We've done a few studies showing that musicians are much better at processing rapidly changing sounds than people without musical training. If musicians are so much better at these abilities, and you need these abilities to read, why not try musical training with dyslexic children and see if that improves their reading," she says.
The study has been reported in the journal Restorative Neurology and Neuroscience.