Reference: St. Louis Post Dispatch August 4, 2011
Disorder has roots in failure to recognize the sounds of speech.
by Pam Belluck New York Times
Many people consider dyslexia simply a reading poblem in which children mix up letters and misconstrue written words. But scientists increasingly have come to believe that the reading difficulties of dyslexia are part of a larger puzzle: a problem with how the brain processes speech and puts together words from smaller units of sound.
Now, a study published last week in the journal Science suggests that how dyslexics hear language may be more important than previously realized. Reasearchers at the Massachusetts Institute of Technology have found that people with dyslexia have more trouble recognizing voices than those without dyslexia.
John Gabrieli, a professor of cognitive neuroscience, and Tyler Perrachione, a graduate student, asked people with and without dyslexia to listen to recorded voices paired with cartoon avatars on computer screens. The subjects tried matching the voices to the correct avatars speaking English and then an unfamiliar language, Mandarin.
Nondyslexics matched voices to avatars correctly almost 70 percent of the time when the language was English and half the time when the language was Mandarin. Experts not involved in the study said that was a striking disparity.
“Typically, you see big differences in reading, but there are just subtle general differences between individuals who are afflicted with dyslexia and individuals who aren’t on a wide variety of tests,” said Richard Wagner, a psychology professor at Florida State University. “This effect was really large.”
Sally Shaywitz, a director of the Center for Dyslexia and Creativity at Yale University, said the study “demonstrates the centrality of spoken language in dyslexia-that it’s not a problem in meaning, but in getting to the sounds of speech.”
That is why dyslexic children often misspeak, she said, citing two examples drawn from real life.
“A child at Fenway Park watching the Red Sox said, ‘Oh, I’m thirsty. Can we go to the confession stand?’ ” she said. “Another person crossing a busy intersection where many people were walking said, ‘Oh, those Presbyterians should be more careful.’ It’s not a question of not knowing but being unable to attach what you know is the meaning to the sounds.”
Gabrieli said the findings underscored a critical problem for dyslexic chidlren learning to read: the ability of a child hearing, say, a parent or teacher speak to connect the auditory bits that make up words, called phonemes, with the sight of written words.
If a child has trouble grasping the sounds that make up language, he siad, acquiring reading skills will be harder.
The research shows that spoken language deficiencies persist even when dyslexics learn to read well. The study subjects were mostly “high-functioning, high-IQ young adults who had overcome their reading difficulty,” Gabrieli said. “And yet when they had to distinguish voices, they were not one iota better with the English-language voices that they’ve heard all their life.”
Experts said the new study also shows the interconnectedness of the brain processes invoiced in reading. Many scientists had considered voice recognition to be “like recognizing melodies or things that are primarily nonverbal,” Gabrieli said.
Voice recognition was thought to be a separate task in the brain from understanding language.
But this research shows that normal reading involves a “circuit, the ability to have all of those components integrated absolutely automatically,” said Maryanne Wolf, a dyslexia expert at Tufts University. “One of the great weaknesses in dyslexia is that the system is not able to integrate these phoneme-driven systems” with other aspects of language comprehension.
Any questions or comments about this article are welcome at www.interactivetherapy.net!
To start the discussion:
A speech language pathologist is often involved with a child’s articulation and/or phonological disorder at earlier ages before a child starts to read. One cannot predict if a child with an articulation or phonological disorder will have a reading/writing problem. It behooves us as educators and speech language pathologists to monitor a child’s development in reading and writing for those children who may be at risk for dyslexia because of difficulty in perceiving, processing and producing sounds in speech. If anyone is doing research on predicting dyslexia based on articulation/phonological disorders, please let me know. It would be a worthwhile study. It would be good to know if those of us working in the field of speech language pathology could lessen the degree of dyslexia before a child learns to read/write or even prevent it.
Pam Hass, Interactive Therapy Inc