I’ve pasted an article from the NYTimes on brain dysfunction and dyslexia. Note the conclusions regarding the worst performing readers!
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July 8, 2003
Two Types of Brain Problems Are Found to Cause Dyslexia
By BONNIE ROTHMAN MORRIS
Dyslexia appears to be caused by two distinct types of brain problems, a new study has found.
The researchers, from Yale, used scanning devices to examine the brains of 43 young adults with known reading disabilities while they performed reading tasks. Another group of 27 good readers were also studied.
All the subjects had been tracked for reading ability since elementary school.
One group appeared to have what the researchers called a “predominantly genetic type” of dyslexia.
These students had gaps in the neural circuitry that the normal readers used for the basic processing of sound and language, but had learned to enlist other parts of the brain to compensate for the difficulty. They still read slowly but can comprehend what they read.
The second group had what the researchers called a “more environmentally influenced” type of dyslexia. Their brains’ system for processing sound and language was intact, but they seemed to rely more on memory than on the linguistic centers of the brain for understanding what they were reading. These students had remained persistently poor readers, scoring poorly on speed as well as comprehension.
The two groups of poor readers were from similar socioeconomic backgrounds and had comparable reading skills when they began school, according to the study, which was published this month in the journal Biological Psychiatry.
But there were two differences: the students who compensated for their problems tended to have higher overall levels of learning abilities, and the students whose problems persisted were twice as likely to attend what the researchers called disadvantaged schools.
The study’s lead author, Dr. Sally E. Shaywitz, said the discovery that the neural systems for reading are intact in the students with the most serious reading problems came as a surprise. It also implies that their problems are more correctable than may have been thought, she said.
“The persistently poor readers have a rudimentary system in place, but it’s not connected well,” Dr. Shaywitz said. “They weren’t able to develop and connect it right because they haven’t had that early stimulation.”
A large body of research has shown that intensive tutoring can correct this kind of reading problem, especially if begun while the children’s brains are still developing.
“If you can provide these children early on with effective reading instruction, these children can really learn to read,” Dr. Shaywitz said.
For the study, participants lay in a brain scanner known as a functional M.R.I. device, and peered through a periscope at monosyllabic words flashed on a computer screen. As they read, pictures were taken of what parts of their brains were doing the work, and how they were working together.
Good readers used three areas in the left side of the brain, to decode letters into sounds, fit them together to make words and process them fluently.
The readers who had compensated but still read slowly did not use the same brain regions for those tasks. Instead, they created an alternate neural pathway, reading mostly with regions on the right side of the brain — areas not as well suited for reading, the researchers said.
Paradoxically, the poorest readers in the study used the same parts of the left side of the brain that the normal readers did to begin the reading process. But instead of connecting that work to other language centers, they then activated a portion of the front right side of the brain that is used primarily for memory to help them along.
That overreliance on memory could help explain the persistence of these poor readers’ problems.
“Once the brain makes the connections it needs for certain tasks, it tends to stick with them,” said Dr. Gordon Sherman, the executive director of the Newgrange School and Educational Outreach Center in Princeton, N.J., an expert on dyslexia who had no connection to the study. “But those connections aren’t necessarily the best ones.”
Rote-based learning of words can get a student to a certain point, but “then it fails quite miserably; there’s too much to memorize,” Dr. Sherman said.
J. Thomas Viall, executive director of the International Dyslexia Association, said that the study’s findings underscored the need for intensive educational intervention, but that more work was needed before its findings of subgroups could be translated into practical applications.
“Dyslexia is a disorder whose treatment is education,” Mr. Viall said. He called the notion of using functional M.R.I. data to identify types of dyslexia “exciting” but added, “We don’t have F.M.R.I.’s in grocery stores like blood pressure machines.”
Dr. Shaywitz acknowledges that giving such tests to every child is impractical, but says researchers will now begin to use the brain connectivity studies to develop other kinds of diagnostic tests.
“It is possible from all that we’ve learned about the science of reading to identify all children who are at risk for experiencing reading difficulty,” she said.
The next step, she added, will be to design early strategies that are tailored to each child’s particular type of disability.
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two types of dyslexia
I think that the New York Times commentary on the article is really big simplification of the scientific findings.
I am not sure whether others can access this link- but here is the original article which I think is worth reading- I believe they had really compared apples and oranges in some cases…
http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6T4S-48XR72C-7-7&_cdi=4982&_orig=browse&_coverDate=07%2F01%2F2003&_sk=999459998&view=c&wchp=dGLbVtb-lSzBA&_acct=C000022720&_version=1&_userid=483692&md5=090f7119340e1191476737683608a62b&ie=f.pdf
Re: Interesting article regarding brain research and dyslexia
Boy, you are right Ewa. The real message here seems to be smarter kids with less disadvantaged schools learn to compenstate better.
They needed kids with the same IQs and same type of schools to really be able to say much.
They didn’t mean genetic and environmentally produced the way I interpreted it at all.
Beth
Re: Interesting article regarding brain research and dyslexia
Beth,
I believe that the issue is even more complicated than that, but you sure get similar impression as me.
“….smarter kids with less disadvantaged schools learn to compensate better. …”
That was exactly what we were told when our son was identified (in 1st grade). I believe this is generally true, however… the emotional effects of “being different” are really hard to evaluate and may play greater role that the specific disorders.
I think that there was however a very optimistic message from this study: the “middle” group- dyslexics but not disadvantaged economically and only slightly worse IQs turned out to comprehend almost as well as non-dyslexics, although they had never really achieve the same basic skills in reading.
Ewa
Re: Interesting article regarding brain research and dyslexia
I’m reading Sally Shaywitz’s book, Overcoming Dyslexia, right now, and she makes it very clear early on in the book that highly intelligent dyslexic people certainly compensate better than those who are not. She sites several people like Nobel prize winners who are tops in their fields.
This sort of concerns me because certainly the majority of dyslexic children are just average, and I wonder why Shawitz does not focus more on them. It sort of makes me think that only affluent, educated parents take their children to Yale for testing, so perhaps she does not see the same kids I see everyday in public school!
Janis
Re: Interesting article regarding brain research and dyslexia
The other thing about the study is that they define reading deficit in relationship to intelligence. So the higher intelligence kids (the remediated ones) don’t have the same starting Woodcock Johnson score. A standard score of 94 is far better than a standard score of 88. So objectively the remediated kids do not have as severe of reading disability to start with. That alone could explain a lot, apart from the higher intelligence and and higher economic status.
My son score was 91 in first grade so he was in between the two groups of dyslexics.
And I agree with you Janis, I think in trying to overcome the negative image of learning disabled people there is this great push on how many really really smart people are dyslexics. All well and good but little encouragement to those of us with kids with “average” IQs.
Still, I do see my own son doing some of the things they associate with higher intelligence—using vocabulary, for example, to compenstate. My son has always has strengths in vocabulary and we del. went to books on tape to make sure he didn’t lose this (he had lost some of his relative advantage as other kids could read at a much higher level than he). I have read in other articles that vocaulary helps kids compenstate and so, as they suggest, I think interventions aimed at improving verbal abilities are a good addition to decoding programs.
Beth
Re: Interesting article regarding brain research and dyslexia
I agree with you 100% about the books on tape. I think that is the number one thing we can do to prevent the Matthew Effect from further depressing the verbal IQ because of lack of learning new vocabulary in books.
And certainly, our kids do have advantages coming from homes with educated parents even though they may not have gifted level IQ’s. So they probably will fall between those two categories!
I’ll have to let you know what I think about the rest of the Shaywitz book.
Janis
testing at Yale
Janis,
just to comment about testing at Yale- we got thi sopportunity (which I deliced when my son was 7 b/c I believed that the brain MRI will be scary experience for him). We got another opportunity for testing last summer, but since he was accepted to the LD school and we were lookind at yet another round of testing, I declined it again.
Neither of the offers was something that other poeple could not have gotten- I just responded to the ad in a Yale’s local newspaper.
Recently I saw a similar ad in our public library that they were looking for children to participate.
Ewa
Re: Interesting article regarding brain research and dyslexia
I understand what you are saying, Ewa, but you have to understand, a lot of public school students’ parents wouldn’t even be reading the paper. And the majority totally let the school IEP team direct the child’s education. I doubt that there are more than a handful of kids in an average district (not a university city) who have had private neuro-psych or APD evals. We just don’t have ads for those kinds of offers in our local paper! I wish we did!
Janis
Re: Interesting article regarding brain research and dyslexia
Janis,
I should hence conclude that more effort should be directed to educating teachers.
yes, there are certainly advantages to living close to Yale, but…just to give you some perspective- this did not protected my son from being thought by “whole language” in 1999 when he was in first grade. And even now our local school is using “four blocks” as a basic reading program… and Reading Recovery as intervention.
Ewa
Re: Interesting article regarding brain research and dyslexia
Oh, nooooooooo!!! Dr. S must get a lot of business with those curriculums in the schools.
Janis
I found this article interesting. It backs up what I have long thought—that there are two types of dyslexia. My son is dyslexic but there is no history of reading problems on either side of our family. He had low grade undiagnosed ear infections that caused hearing loss (tubes at age 4). The lack of early stimulation and the intermittent nature of his ear infections (never seemed to be there when we had physicals) had been supposed by a number of professionals to be the cause of his problems (overlaid on some genetic auditory weaknesses—but compenstated fine by other family members).
My son’s problems happen to be quite severe but I thought he was an anomoly rather than characteristic of a particular type of dyslexic.
Thanks for sharing.
Beth