"With about 112 hours of phonic-based instruction, adults with dyslexia had significant improvements in reading and changes in brain activity while reading," said Lynn Flowers, Ph.D., senior researcher, from Wake Forest Baptist. "We know that dyslexia is not something children outgrow, and our findings suggest that it's never too late for instruction to overcome this disability."
This was the first independent research study of whether phonics-based instruction is effective in adults with dyslexia and the first to measure whether the instruction would result in changes in brain activation. Dyslexia, or difficulty learning to read, has been associated with underactivity in areas of the brain that process language and "decode" words into groups of letters that are associated with meaningful sound patterns.
The research involved 19 adults with dyslexia and 19 typical readers without dyslexia. The mean age of participants, who were mostly from the Winston-Salem area, was 42.5.
Dyslexia is the most common learning disability and affects about 10 percent of the population. "A huge number of adults have this problem, so it's important to know whether something can be done to treat it," said Flowers, an assistant professor of neurology. "Adults with dyslexia can suffer significant financial and emotional consequences."
The researchers used functional magnetic resonance imaging (fMRI) - which shows brain activation during a task - to verify whether adults with dyslexia process language differently from typical readers. The testing - performed while participants completed a phonics task - showed that several areas of the brain, predominantly on the left side, were less active in participants with dyslexia. These areas are associated with processing phonetic sounds and recognizing familiar objects.
"This verified our findings and those of others and confirms that dyslexia is biologically based," said Flowers.
The researchers then tested to see if instruction in phonics would improve reading ability and produce changes in brain activation. Half of the participants with dyslexia received phonics-based instruction 15 hours a week for eight weeks. Before the instruction began, they completed pen-and-paper tests to measure their reading ability and underwent fMRI. After the instruction, they completed a second round of written and fMRI testing.
The written tests showed that participants who received instruction made gains of between six and 23 percent in text reading, phonetic awareness and the ability to "decode" the written word. fMRI testing revealed that the improvements in reading corresponded to increased activity in areas of the brain associated with phonetic processing, being able to associate a symbol with a sound and being able to recognize whether a string of letters represents a word.
Flowers said the gains in reading ability were significant enough to make a difference in the everyday lives of participants.
"One woman who had never read a book now sets her alarm clock early to get up and read before going to work," she said.
Flowers said phonics-based instruction was chosen for the research because it has proven successful in children. She said the researchers are currently working to see if a less intensive program will have the same benefits.
She recommends that adult dyslexics who want to get reading instruction select a phonics-based program that focuses on the structure of language and how language works. It should also involve multiple senses, including how a letter looks, sounds and feels.
Flowers' co-authors were Guinevere Eden, D. Phil., Karen Jones, Katherine Cappell, Lynn Gareau, Thomas Zeffiro, M.D., Ph.D., Nichole Dietz, Ph.D, and John Agnew, Ph.D., from Georgetown, and Frank B. Wood, Ph.D., from Wake Forest Baptist.
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About Wake Forest University Baptist Medical Center: Wake Forest Baptist is an academic health system comprised of North Carolina Baptist Hospital and Wake Forest University Health Sciences, which operates the university's School of Medicine. The system comprises 1,282 acute care, psychiatric, rehabilitation and long-term care beds and is consistently ranked as one of "America's Best Hospitals" by U.S. News & World Report.