Brain Defect Underlies Reading Difficulties of Dyslexia
The work is "further evidence that dyslexia has biological roots," says Eden.
And it is important because it shows that "dyslexia is not an auditory problem and not a visual problem -- it's a problem with the auditory-visual connection," says Frank Wood, PhD, chief of neuropsychiatry at Wake Forest University School of Medicine in Winston-Salem, N.C.
To see if those biological problems can be overcome, Eden and her colleagues did brain scans on 20 dyslexic adults, then put 10 of them on an intensive training program. The program, which was designed to improve reading skills, consisted of three hours per day of training for eight weeks.
The 10 dyslexics who received the training learned to read, even forming a book club at the end of the training period. What's more, they compensated for the weak performance of their left parietal lobe by learning to use their right parietal lobe. According to Eden, the results show that the adult brain is capable of change. "It says you shouldn't give up on adult dyslexics," she says.
Knowing a biological cause for dyslexia should help researchers come up with better ways of diagnosing the disorder. Currently, most children are not diagnosed as dyslexics until they are in the second or third grade and have a hard time reading. "As a society, we're not doing a very good job at diagnosing children at risk for reading failure," Zeffiro says.
But understanding the specific brain functions and regions that go awry should allow researchers to come up with better diagnostic tests for children as young as 4 or 5. Those at-risk children could be directed to an intervention program that would help them learn to read better, Zeffiro says.
Parents should be aware that young children are at risk of dyslexia if at least one parent or relative has it, says Wood. And they should also be wary of quick and easy fixes for dyslexia. "Dyslexia can only be treated by trained teachers," he says.