Brain Images Show Biological Basis of Dyslexia
When diagnosing dyslexia, schools often rely on IQ tests in their evaluation. However, a new study has found that there are great similarities in brain patterns between poor readers with typical IQs— those that traditionally qualify for special ed services—and poor readers with low IQ, who do not meet the standard for services.
Using brain imaging scans (functional MRI), researchers at the Stanford University School of Medicine studied brain activation processes of 131 children, ages 7 to 16 while they completed a simple reading task. The children were divided into three groups:
- Typical readers with typical IQs
- Poor readers with typical IQs
- Poor readers with low IQs
The findings, recently reported in Medical News Today (MNT), showed that brain patterns were similar in both groups of poor readers and differed significantly from patterns exhibited by typical readers.
This study adds to the growing body of research that shows similar difficulties exist among poor readers, regardless of their cognitive ability, leading senior researcher, Fumiko Hoeft, MD, Ph.D, to conclude that “IQ should not be emphasized in the diagnosis of reading abilities.” According to the MNT article:
Hoeft noted that the results are timely. The Diagnostic and Statistical Manual of Mental Disorders, the standard diagnostic guide for mental illnesses and brain disorders, is currently being revised, and there is a proposal to change it so that IQ wouldn’t be taken into consideration when diagnosing dyslexia. (The new version, DSM V, will be released in 2013.) This work, she said, is the ‘first study reporting biological neuroimaging evidence to support’ that change.
Hoeft and her colleagues also point out that these and other findings indicate that “any child with a reading difficulty, regardless of his or her general level of cognitive abilities (IQ), should be encouraged to seek reading intervention.”
Stanford University Medical Center. (2011, September 30). “Brain Imaging Study Shows Physiological Basis Of Dyslexia.” Medical News Today. Accessed from http://www.medicalnewstoday.com/releases/235222.php.