Imaging Study Reveals Brain Function of Poor Readers Can Improve
A brain imaging study has shown that, after they overcome their
reading disability, the brains of formerly poor readers begin to
function like the brains of good readers, showing increased activity
in a part of the brain that recognizes words. The study appears
in the May 1 Biological Psychiatry and was funded by the
National Institute of Child Health and Human Development (NICHD),
one of the National Institutes of Health.
"These images show that effective reading instruction not
only improves reading ability, but actually changes the brain's
functioning so that it can perform reading tasks more efficiently,"
said Duane Alexander, M.D., Director of the NICHD.
The research team was led by Bennett Shaywitz, M.D., and Sally
Shaywitz, M.D, of Yale University, in New Haven, Connecticut. Other
authors of the study were from Syracuse University, in Syracuse,
New York; Vanderbilt University, in Nashville, Tennessee; and the
NICHD.
According to Dr. Sally Shaywitz, the results show that "Teaching
matters and good teaching can change the brain in a way that has
the potential to benefit struggling readers."
Along with testing the children's reading ability, the researchers
used functional magnetic resonance imaging (fMRI), a sophisticated
brain imaging technology, to observe the children's brain functioning
as they read.
In all, 77 children between the ages of 6 and about 9 and ½
took part in the study. Of these, 49 had difficulty reading, and
29 children were good readers. Of the 49 poor readers, 12 received
the standard instruction in reading that was available through their
school systems. The remaining 37 were enrolled in an intensive reading
program based on instruction in phonemic awareness and phonics.
In the study, the 37 poor readers in the intensive reading program
outpaced the 12 poor readers in the standard instruction groups,
making strong gains in three measures of reading skill: accuracy,
fluency, and comprehension. These gains were still apparent when
the children were tested again a year later. Moreover, fMRI scans
showed that the brains of the 37 formerly poor readers began functioning
like the brains of good readers. Specifically, the poor readers
showed increased activity in an area of the brain that recognizes
words instantly without first having to decipher them.
The intensive reading program the 37 children took had strong components
in phonemic awareness and phonics. Phonemic awareness refers to
the ability to identify phonemes, the individual sounds that make
up spoken words. The word "bag," for example, is made
up of three such elemental units of speech, which can be represented
as bbb, aaa, and ggg. The brain strings together the 40 phonemes
making up the English language to produce hundreds and thousands
of words. In speech, this process is unconscious and automatic.
Beginning in the 1970s, NICHD-funded researchers learned that developing
a conscious awareness of the smaller sounds in words was essential
to mastering the next step in learning to read, phonics. Phonics
refers to the ability to match spoken phonemes to the individual
letters of the alphabet that represent them. Once children master
phonics, the NICHD-funded studies showed, they could make sense
of words they haven't seen before, without first having to memorize
them. Further NICHD-supported research found that instruction in
phonemic awareness was an essential part of a comprehensive program
in reading instruction that could help most poor readers overcome
their disability.
In the 1990s, the Shaywitzes had used fMRI to learn that reading
ability resides in the brain's left half, or hemisphere. Within
the hemisphere, three brain regions work together to control reading.
In the left front of the brain, one area recognizes phonemes. Further
back, another brain area "maps" phonemes to the letters
that represent them. Still another brain area serves as a kind of
long-term storage system. Once a word is learned, this brain region
recognizes it automatically, without first having to decipher it
phonetically.
Poor readers, the researchers had learned in the earlier studies,
have difficulty accessing this automatic recognition center. Instead,
they rely almost exclusively on the phoneme center and the mapping
center. Each time poor readers see a word, they must puzzle over
it, as if they were seeing it for the first time.
In the current study, the researchers discovered that, as the 37
poor readers progressed through their instruction program, their
brains began to function more like the brains of good readers. Specifically,
the brains of these children showed increased activation in the
automatic recognition center.
"This study represents the fruition of decades of NICHD-supported
reading research," said G. Reid Lyon, Ph.D, Chief of NICHD's
Child Development and Behavior Branch. "The findings show that
the brain systems involved in reading respond to effective reading
instruction."
The NICHD is part of the National Institutes of Health (NIH),
the biomedical research arm of the federal government. NIH is an
agency of the U.S. Department of Health and Human Services. The
NICHD sponsors research on development, before and after birth;
maternal, child, and family health; reproductive biology and population
issues; and medical rehabilitation. NICHD publications, as well
as information about the Institute, are available from the NICHD
Web site, http://www.nichd.nih.gov,
or from the NICHD Information Resource Center, 1-800-370-2943; e-mail
NICHDInformationResourceCenter@mail.nih.gov.
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