The University of Washington’s Dyslexia Research Findings
Dyslexia affects one in five students and it is the most common learning disability.
An interdisciplinary team of University of Washington researchers have found for the first time that there are chemical differences in the brain function of dyslexic and non-dyslexic children. They found, too, that dyslexic children use nearly five times the brain area as normal children while performing a simple language task. This research was published in the American Journal of Neuroradiology.
The researchers used PEPSI to capture the brain activity of the subjects. PEPSI is 32 times faster than conventional magnetic resonance spectroscopy. Software developed at the University of Washington enabled the researchers to detect specific brain chemicals.
The dyslexic and non-dyslexic boy tudents were well-matched with age, IQ, and head size, but not in reading skills. The non-dyslexics control group was reading at a level above normal for their age. The dyslexics had delayed reading skills and they all had a family history of dyslexia. The subjects were fitted with earphones and they were asked to perform four tasks while their brains were being imaged. Three of the tests involved pairs of words and the fourth used pairs of musical tones. The results of the language tests showed that the dyslexics exhibited nearly five times more brain activation during a language task that asked them to interpret the sounds of words while there was no difference in the two groups during the musical tone test. So, this means that the difference between the dyslexics and the non-dyslexic boys relates to auditory language and not to nonlinguistic auditory function.
The findings are important because they shed new light on brain mechanisms involved with dyslexia at a developmental stage when it is still amenable to treatment. Also, the functional differences between dyslexics and control subjects add evidence that dyslexia is a brain-based disorder.
The dyslexics were using 4.6 times as much area of the brain to do the same language task as the control students. The dyslexics’ brains were working a lot harder and using more energy than the non-dyslexic children. Schools and teachers must become aware of how hard it is for dyslexic children to do a task that others do so effortlessly; they must provide accommodations for them. There are definite learning differences in children.
The research findings are exciting, but considerably more research is needed to precisely define the chemical and neurological markers of dyslexia. What the researchers found is a metabolic marker, but there could be a more fundamental cause. We need to understand the molecular and neural mechanisms underlying dyslexia.