Imaging study shows little difference between poor readers with low IQ and poor readers with high IQ
Last year, Fumiko Hoeft, MD, PhD, authored a study that used sophisticated brain imaging to predict with 90 percent accuracy which teenagers with dyslexia would improve their reading skills over time. Now the Stanford imaging expert has turned her attention to the diagnosis of the learning disability, and she and colleagues have provided “biological evidence that IQ should not be emphasized in the diagnosis of reading abilities.”
As I explain today in a release, schools and psychologists sometimes rely on a child’s IQ to define and diagnose dyslexia: If a child’s reading achievement is below expectation based on IQ, he would be considered dyslexic, while a poor reader with a low IQ would receive some other diagnosis. (And those children not considered dyslexic might not be given access to the proper reading interventions.) But in an imaging study of 131 children - including poor readers with typical IQ, poor readers with low IQ and typical readers with typical IQ - Hoeft and colleagues show that what happened in the brains of poor readers during a reading task was similar regardless of IQ:
In the fMRI analysis, researchers found that both groups of poor readers exhibited significantly reduced activations relative to typical readers in the left inferior parietal lobule and left fusiform gyrus. The researchers also used a sophisticated analysis to determine that the brain patterns of each group of poor readers looked liked those of the other group of poor readers more than 80 percent of the time, and did not often resemble the patterns from the normal readers.
The researchers said that their work, which will appear in an upcoming issue of Psychological Science, indicates 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.” And:
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.
Previously: Stanford study furthers understanding of reading disorders and Researchers use brain imaging to predict which dyslexics will learn to read
Photo by Marc Samson
September 28th, 2011 at 1:59 pm
So what happens to the children who have been diagnosed using the previous method? Do all of them have to be reevaluated?
September 29th, 2011 at 12:50 pm
This depends on a number of factors, but in general, children with learning disabilities should always get evaluated on a regular basis or whenever necessary as children’s developmental trajectory depends on that individual,
In this case, rather than getting evaluated, it is worth talking to the specialist who did the evaluation who should have the results form the evaluation. You can discuss whether there was a discrepancy with aptitude and achievement and can take it from there. Ultimately, decisions about diagnoses and accommodation often depend on the State and school district unfortunately.
We hope that past research showing no difference in the phonological deficit and response to intervention in the two groups of poor readers together with our brain imaging finding will inform policy and educational practice.
October 6th, 2011 at 4:18 pm
In my experience, children and adolescents with disabilities and a low IQ may be overlooked as candidates for intensive reading intervention. The presumption may be that the student is “doing the best that s/he can.” It is essential that public school educators, parents, and private assessors share this important research with IEP teams so that students with disabilities receive a free and appropriate public education (FAPE). It is also essential that attorneys introduce this type of evidence in special education due process hearings to help administrative law judges analyze whether a child with unique needs in the area of reading has been offered appropriately intensive reading intervention.
October 11th, 2011 at 7:34 pm
There are two groups of learners that have been misrepresented by the over-reliance on IQ to determine certification for reading disability services and eligibility for special educational consideration. Students with a low IQ are presumed to be doing the best that can be expected. But they may still be perceived as needy and frequently provided with social supports.
In my experience, the students with a high IQ and who struggle with reading decoding and fluency are much more at risk for dropping out, underachieving, developing antisocial behaviors and attempting suicide. They are presumed to not be sufficiently disabled to warrant intervention because their reading achievement scores are close to their grade placement; although the inconsistent scores are not commensurate with their vocabulary, comprehension and general knowledge. The emotional wreckage that results from ignoring their struggle is totally unnecessary. Without appropriate intervention, they are left on their own to resolve the self-recrimination from the disparity between comments about how smart they are, and the struggle with producing work that reflects their intelligence.
Excellent research-proven interventions can be provided for identified subsets of students who learn differently or progress at different rates. The current educational trend, “Response to Intervention”, an educational tracking and grouping strategy, should not be mistaken as a diagnostic tool. Education that is targeted to the identified specific needs of individual learners needs to be revisited. Hopefully research like this will contribute to an array of diagnostic tools that are not based on societal bias and simplistic mechanized education.
Longitudinal studies would help with understanding of the impact of maturation and perhaps pinpoint optimal times to provide instruction.