Remediation training improves reading ability of dyslexic children
BY LISA TREI
Stanford Report, Tuesday, February 25, 2003
For
the first time, researchers have shown that the brains
of dyslexic children can be rewired -- after undergoing
intensive remediation training -- to function more
like those found in normal readers.
The training program, which is designed to help dyslexics
understand rapidly changing sounds that are the building
blocks of language, helped the participants become better
readers after just eight weeks.
The findings were released Monday in "Neural deficits
in children with dyslexia ameliorated by behavioral remediation:
Evidence from functional MRI," published by the Proceedings
of the National Academy of Sciences Early Edition.
"It
was very dramatic to see the huge differences that occurred
in the brains of these children," said Stanford psychology
Professor John Gabrieli, one of the study's authors. "The
intervention, although substantial, only covered eight
weeks. One note of optimism about the study is that such
a limited intervention can have a substantial effect on
reading scores."
Brain imaging scans of the children who participated in
the training showed that critical areas of the brain used
for reading were activated for the first time, and that
they began to function more normally. Furthermore, additional
regions of the brain were activated in what the researchers
believe the dyslexics may have used as a compensatory
process as they learned to read more fluently.
Gabrieli said the study's findings may help demonstrate
how different kinds of reading programs can tackle various
problems faced by poor readers. "This is showing us for
the first time the specific changes in the brains of children
receiving this sort of treatment, and how that is coupled
with the improvement they have in reading and language
ability," he said. "We're hoping that this becomes an
additional tool to understand how educational remediation
programs alter children's abilities, as they must do,
by changing the way their brains process information."
Study co-author Paula Tallal, professor of neuroscience
at Rutgers University and a founder of Scientific Learning
Corporation, the Oakland-based company that designed the
program, said the findings are also important because
it is the first time a commercial product has been proven
scientifically to work using standardized educational
testing and brain imaging. Scientific Learning's computer
program, Fast ForWord Language, focuses on helping
children become more fluent at processing the rapidly
changing sounds, she said.
"In
light of President [George W.] Bush's legislation, No
Child Left Behind, which mandates that only scientifically
validated applications be used for intervening with children,
this program has the potential to address the crisis we
are facing in the number of children failing to meet [educational]
standards," she said. The No Child Left Behind Act of
2001 places an emphasis on teaching methods that have
been proven scientifically to work.
Dyslexia, sometimes called "word blindness," is a common
disorder, affecting 5 to 10 percent of Americans, Gabrieli
said. It is defined as a specific difficulty in reading
that is severe enough to interfere with academic functioning
and cannot be accounted for by lack of educational opportunities,
personal motivation or problems in sight or sound. Tallal
said that studies estimate that about 40 percent of people
with dyslexia inherit it genetically. Other factors believed
to trigger the disorder include prematurity at birth,
developmental language impairment and attention deficits,
she said.
Dyslexics have trouble distinguishing between letters
that rhyme, such as 'B' and 'D.' "If you hear the sound
'ba' in butter and 'da' in Doug, the only way we know
the difference is in the first 40 milliseconds of the
onset of those sounds," Tallal explained. "The ability
to extract the sounds out of words is what is called phonological
awareness. We have to be aware that words can be broken
into sounds, called phonemes, and that these sounds have
to be identified with letters." This process might appear
intuitive, but it is a learned skill, Tallal said.
The training program the children took part in was targeted
at helping them learn to process and interpret the very
rapid sequence of sounds within words and sentences by
exaggerating and slowing them down. "These are the building
blocks you have to have in place before you can learn
to read," Tallal said. "I think Fast ForWord is
building the scaffold for reading, and doing it based
on scientific knowledge of the most efficient and effective
way of helping the brain learn."
The study
The study included 20 dyslexic children aged 8 to 12 years.
Their brains were scanned using functional magnetic resonance
imaging (fMRI) at Stanford's Lucas Center for Magnetic
Resonance Spectroscopy before and after participating
in the eight-week training program. A control group of
12 children with normal reading abilities also had their
brains scanned but did not participate in the training.
The scanning machines, which look like beds that slide
into small tubes, normally are used to check for brain
injuries or tumors, Gabrieli said. With slightly different
software they can be used to measure which regions of
the brain are active by looking for changes in blood oxygenation,
a process that occurs in parts of the brain where the
neurons are active.
Study lead author Elise Temple, assistant professor in
human development at Cornell, headed the research as a
graduate student at Stanford. Both the dyslexic children
and the control group were asked to perform a simple rhyming
task while having their brains scanned. Participants were
shown two uppercase letters and told to push a button
if the two letters rhymed with each other. For example,
'B' and 'D' would match, but not 'B' and 'K.'
Twenty-minute sessions were broken into five-minute segments,
during which the children had to stay completely still.
Afterward, they were rewarded with Pokémon or baseball
cards, and given a picture of their brain to take home.
Before the sessions started, Temple allowed the children
to play around the machines, which can be claustrophobic,
to help them become comfortable with the testing process.
"In this study, it was especially important not to have
the experience be a bad one because we wanted them to
come back," Temple said.
During the rhyming exercise, children with normal reading
showed activity in both the language-critical left frontal
and temporal regions of the brain, the latter of which
is behind and above the left ear. Dyslexics, however,
struggled with the task and failed to activate the temporal
region, and showed some activity only in the frontal brain
area.
Afterward, the dyslexic children used the Fast ForWord
Language computer program for 100 minutes a day, five
days a week, as part of their regular school day. "The
computer games were fun, the kids liked them," Gabrieli
said. The program consisted of seven exercises that rewarded
players when they answered questions correctly. For example,
when a picture of a boy and a toy was shown, a voice from
the computer would ask the player to point to the boy,
a step that required understanding the very brief difference
in the sound of the first consonant in each word. Initially,
the questions were asked in a slower, more exaggerated
fashion than in normal speech to help the children understand
the sounds inside the words. As the player progressed,
the speed of the voice in the program slowly increased.
"Each child worked at his or her own level," Tallal said.
"The goal was to leave all children processing sounds
correctly in words and sentences of increasing length
and grammatical complexity."
The results
Following the training, the dyslexic children's scores
went up in a number of language and reading tests, Gabrieli
said. "The study supported the idea that for some children,
getting training on just simply processing rapid sounds
is a route to becoming much more fluent and capable readers,"
he said. In addition, activation of the children's brains
fundamentally changed, becoming much more like that of
good readers. "We see that the brains of these children
are remarkably plastic and adaptive, and it makes us hopeful
that the best language intervention programs in the future
can alter the brains in fundamentally helpful ways," he
said.
It is likely that the children will continue to need considerable
help in reading, Gabrieli said. "This is not a one-shot
vaccine," he said. "But it makes them much more prepared
to take advantage of a regular curriculum to read successfully
and do well."
The next step, Temple said, is to see if other commercial
programs can alter the brain as well. "I don't know if
these changes are unique to this program," she said. "Are
there some training programs that are better for some
kids than others?" A future goal would be to offer a series
of tests to help select which programs best meet a child's
needs, she said.
For many years, Gabrieli said, the nation has been concerned
with the best methods to teach reading. "We're hoping
that this becomes one piece of many pieces of research
that will help us better understand ... what are effective
ways to rescue children who have trouble reading," he
said. In addition, the study brings the scientific use
of brain imaging into the arena of education. "We'd like
to use these cutting-edge tools of neuroscience to somehow
directly assist thoughts about educational curricula,
policies and ways to help children perform better in school
and look forward to better futures," he said.
In
addition to Temple, Tallal and Gabrieli, the paper was
written by Gayle K. Deutsch, a senior clinical scientist
at Stanford; Russell Poldrack, a former postdoctoral student
at Stanford and currently assistant professor of psychology
at the University of California-Los Angeles; Steven L.
Miller of Scientific Learning Corporation; and Michael
M. Merzenich, a founder of Scientific Learning and a professor
at the University of California-San Francisco. The Haan
Foundation for Children helped fund the study.