Dyslexia Begins when the Wires don’t Meet
The work done by Dr. Just and his colleagues at Carnegie Mellon, as well as brain imaging carried out at Georgetown University, Yale University and other centers, has now proven that seeing letters in reverse or out of order is not the cause of of dyslexia.
Using functional magnetic resonance imaging, which can measure blood flow to different parts of the brain in real time, researchers now know that the reading disability involves a weakness in the part of the brain that decodes the sounds of written language…
“When we first learn how to read,” she said, “it’s effortful. But after you’ve read a word a certain number of times, those nerve endings come together and then it’s stored in the word-form area.”
In many adults with dyslexia, however, the word-form area stays largely dormant. For them, every word remains a puzzle that needs to be unraveled.
It might seem that the new brain studies amount to a grim prognosis for an ingrained disability.
But they have also shown that the right kind of intensive instruction can start to rewire the brain and help overcome reading deficits, even if it can’t eliminate them…
So even moving people a little way forward on the path to reading better can be beneficial, he said. “Being a slow reader is a surmountable impediment. Many, many professionals are slow readers. They take longer, but they can do it.” …
One reason for the wide range of estimates is that the classic definition of a person with dyslexia is someone of average or above-average intelligence who has poor reading skills.
But there are also millions of people with below-average intelligence who are poor readers, and it’s not clear how many of them have the brain problems associated with dyslexia, and how many struggle with reading for other reasons…
In fact, Dr. Henry said, if a child is still reversing his letters in first or second grade, it’s a good indicator that he may have dyslexia, she said…
Most of the brain imaging research on dyslexia so far has been done on English-speaking people, but the problem exists throughout the world…
There is even dyslexia in China and Japan, where the written symbols represent whole words, Dr. Eden said, but in those nations, the brain differences between good and poor readers show up in frontal regions that seem to be involved in processing the shapes of the symbols.
The brain imaging researchers are not experts on reading instruction methods, but their work on dyslexia has convinced them of one thing.
For children with dyslexia, the “whole language” approach to reading — which stresses seeing whole words and saying them aloud — does not work well.
The best interventions, they say, are letter-to-sound decoding techniques that are even more detailed and concrete than regular phonics classes.
Source: Post-Gazette.com
http://www.post-gazette.com/pg/07042/760823-114.stm
February 11th, 2007 at 10:10 PM
“In fact, Dr. Henry said, if a child is still reversing his letters in first or second grade, it’s a good indicator that he may have dyslexia” your article quote not mine.
A reasonable question to ask is why when looking at a single area of the brain the results between dyslexics and non dyslexics overlap.
The reason that some people still consider a visual basis for dyslexia is that a minority of dyslexics do have a visual basis for their problem. The problem with conclusions about dyslexia is the assumption of one cause.
Dr Eden is a perfect example of the single cause of dyslexia theory. Her quote that giving something a long name makes it believable is inane.
Using her as an example, she first reported in the 1980’s that dyslexics see differently. I remember a graphic that had letters walking along with a quote from a dyslexic girl (as reported by Dr Eden )about how reading was difficult because of the walking letters.
When she investigated the language processing center of the brain she threw out the vision data and announced that dyslexia was caused by language processing difficulties.
Her next development was the study of the structural differences in the brain and that has become the cause of dyslexia. This was followed by the plasticity of the brain showing changes in the brain due to interventions.
In her last study she was again back to studying the visual centers of the brain and again seeing differences.
Now, I do not question any of the brain imaging results. I do note the fact that the differences observed ( when looking at any single brain location ) only show up when comparing groups and individuals have overlap with non dyslexics that result in the inability to identify individuals with dyslexia by those methods. This overlap between dyslexics and non dyslexics is seen when any single brain location is studied.
I suggest that the dyslexics in those studies whose results overlap non dyslexics actually have their dyslexia caused by different factors than what is being studied. I suspect that 1 subgroup that is partly at fault has visual processing problems. This also works in reverse when studying the visual centers by the phonologically impaired.
Having a group of dyslexics made from dyslexics that actually have different factors causing their dyslexia would produce the results that so far make it impossible to identify individual dyslexics from analysis generated by 1 brain location. I think that dyslexia has more than one cause the more reasonable conclusion rather than there is one cause.
The prejudice against visual problems being involved with dyslexia partly is generated the public response to those overselling the concept that there is a single color for a particular dyslexic that will help their dyslexia. When the evaluation is actually the product being sold there is no recourse when there is failure and no financial reason to limit those tested as the profits are the same for both success or failure.
This failure of high priced evaluations to determine a particular color for a particular dyslexic should not result in the conclusion that dyslexics have no visual problems. All the failure does is to make it a financially risky action to try those high priced evaluations.
If we take those walking letters as reported by the dyslexic girl in Dr. Eden’s study on the visual centers as being a real problem then I would think she would know if something stopped that problem when the letters no longer were walking. If a dyslexic’s visual problem can be described then there should be no question about knowing if that problem is removed.
I sell a niche product that claims and is guaranteed to remove any described visual problem that makes reading difficult for dyslexics without an evaluation. More information at http://www.dyslexiaglasses.com . The only risk involved is that return shipping is not included.
Some people believe the evidence actually shows there may be more than one cause of dyslexia are not convinced that the visual problems such as those reported as walking letters or seeing the page as if behind a waterfall are adequately explained by the phonological explanation of dyslexia.