High-Tech Hope for Children With Language Disabilities
Using specially designed computer games, CD-ROM books and audiotapes, a bicoastal team of language researchers has developed a pioneering therapy that they believe has the potential to correct language learning disabilities that afflict as many as 7 million U.S. children.
Such children, who have trouble understanding and using the spoken word, typically go on to develop the reading problems characteristic of dyslexia, a widespread impairment of reading ability.
Current therapies involve intensive, expensive--and often frustrating--one-on-one intervention by specially trained teachers and may continue for years.
The new approach, which uses computers to train the brain to recognize hard-to-hear sounds, has been shown to accomplish in a month the same goals that conventional therapy achieves in two or more years.
Some experts say it is like providing glasses for the ears.
The techniques, developed at Rutgers University in New Brunswick, N.J., and UC San Francisco, are described today in two papers in the journal Science.
“This represents a breakthrough in the understanding and treatment of a type of learning disabilities that takes a tremendous toll on individuals and society,” said David Mahoney, chairman of the Charles A. Dana Foundation, which funded the studies.
“This is the first significant, practical therapy that has been offered,” said linguist Susan Curtis of UCLA. “The idea of taking a therapy, bringing it home and having it ameliorate a fundamental and profoundly devastating developmental problem is of tremendous significance.”
The new therapy is based on more than two decades of research into the causes of language learning disabilities by neuropsychologist Paula Tallal of Rutgers. She reported last year that the major problem in about 85% of these children is that their brains do not operate fast enough to distinguish many different sounds.
When an individual hears a sound, “brain cells require a certain amount of time to respond, recover and be ready to respond again,” Tallal said.
In normal individuals, this response occurs very quickly, on the order of 30 to 40 milliseconds. For language learning-impaired children, the process takes 100 milliseconds or longer.
But many speech sounds, particularly the so-called stop-consonant syllables such as ba, da, ga, pa, ta and ka, have a very short transitional period in which the initial spoken consonant sound changes to the vowel. The initial “b” in ba, for example, lasts for only 40 milliseconds before switching to the “ah” sound.
Because the brains of the language learning-impaired children do not respond rapidly enough, they have great difficulty distinguishing these sounds, Tallal has found. This language learning disorder translates into dyslexia, as children enter school and learn to associate speech sounds with letters.
Based on this insight, neuroscientist Michael Merzenich and his colleagues at UC San Francisco used computers to alter speech, accenting the stop-consonant syllables so they stand out from the rest of the speech and lengthening them so that the children could recognize them.
Modifying speech in this manner before it reaches the ears of the language learning-impaired is like putting corrective lenses in front of the eyes of the nearsighted, Merzenich said.
Using the altered speech, they developed video games that reward the user when he or she recognizes the stop-consonant sounds and responds appropriately. As the user’s proficiency increases, the syllables are progressively shortened until they are recognized in real time.
The team also used the same technology to record stories on CD-ROMs and audiotapes that the children could listen to at home.
Tallal first tried the programs on a group of seven children, ages 5 to 10, at Rutgers last summer and found that all seven developed normal or near-normal language capabilities within a few weeks.
“When we first got the result, I was really surprised,” she said, because she believed that the children’s conditions were permanent. “I was surprised that it worked, but more surprised at how dramatic the change was. . . . [The children] were like different little people.”
Emboldened by the results, she studied a second group of 22 children. Half received the therapy. The other half played similar video games without the speech enhancement, but received all the attention the first group did. After a month, the control group had shown some progress, but those who received the new therapy had progressed to nearly normal language levels. Tests six months later showed that their language abilities had been retained.
Merzenich conceded that the group of children tested was relatively small, but argued that “the results are very highly statistically significant. There is no uncertainty at all about the positive results of these experiments. The surprise was that it had a very positive impact on every child. . . . Every child made significant progress, both in ability to identify rapid speech and in language comprehension abilities.”
“It is a small group of children,” Tallal added, “but they were severely delayed in language and reading skills. . . . We have every reason to believe that the results are going to generalize to much larger numbers of children.”
To test that conclusion, the team is organizing a much larger trial of thousands of children at centers nationwide. “We want to take it out of the laboratory and make it work in the clinic or classroom,” Tallal said. “We want to expand it to reading and develop materials for teaching.”
For further information about the technique, the team can be reached at (800) 890-0445.
Information is also available at their web site:
https://www.ld.ucsf.edu
