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When Owen Johansen first started school, he would often return home in tears. "He'd be so upset because he had so much trouble keeping up," says his mother, Pat. "He'd say he wasn't as smart as all the other kids."
It started to become clear that Owen had a reading-related problem when his teachers had him repeat kindergarten because he couldn't identify letters—let alone sound them out. "I'd spend an entire week working with him on just one letter," remembers Pat. "We'd cut out pictures of the letter together, then I'd hold it up and ask him, 'OK, what letter is this?' and he wouldn't know. He'd get really upset."
Owen's problem was especially perplexing because his inability to perform simple reading tasks didn't mesh with his superb spoken vocabulary or ability to understand other subjects. "Owen would just inhale information," says Pat. "In kindergarten, he had a 5th grader's general knowledge. But he somehow couldn't learn the alphabet." Soon after, they took Owen for testing at Children's Hospital Boston, where doctors found that he had profound dyslexia, as well as attention deficit disorder (ADD). The Children's doctors recommended a special education plan and prescribed medicine for his ADD. And even though they couldn't offer him a simple cure, the diagnosis itself came as a relief to his parents. "It was so important to learn he was dyslexic so we could start getting him the help he needed and so he could show everyone just how smart he really was," says Pat.
Dyslexia is a challenging condition to diagnose, treat or even define. It affects between 5 and 17 percent of children in the United States, all of whom, like Owen, have reading difficulties that aren't in proportion to their levels of intelligence. Although researchers have determined that dyslexia isn't related to a child's socioeconomic background, level of education or primary language spoken, they still haven't been able to pinpoint its exact causes.
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This may be because there is no one "dyslexia" to define. Since reading involves so many activities the brain controls—sound processing, eye movements and language centers are all required to take a visual image and convert it into words and turn those words into meaning—any glitch in the process can result in reading problems. These problems have historically been lumped together under the umbrella term of dyslexia. "Reading is the hardest thing that our brain has to do," says Chris Walsh, MD, PhD, Children's chief of Genetics, who is studying dyslexia by examining genes involved in directing how the brain develops. "We don't read until we're 6 or 7 because it involves all of those other skills that you spend your first six years learning. It's so hard for the human brain, it's a miracle that it even happens at all."
By examining brain imaging of children who can't process fast changes within sounds, Walsh and other Children's researchers are working to find answers to some basic questions about dyslexia: Does each subtype of the condition have a different cause? What are the best treatments? Is it a permanent disability? As they make discoveries, they're also making a case for redefining the condition and how it's treated. "As we recognize that dyslexia is many different conditions, it allows us to develop scientific approaches to dissect that complexity," says Walsh. "We need to attack the pieces one at a time, rather than trying to solve the whole puzzle at once."
Walsh runs a laboratory at Children's that aims to identify genes that cause autism, dyslexia, forms of mental retardation and epilepsy. He's especially interested in applying gene studies to dyslexia since the condition runs in his own family. "My brother and uncle struggled a lot with reading and it got me thinking about how genes relate to reading ability," he says. "I've always been fascinated with that link. How can something as concrete as a gene relate to something so seemingly psychological and social?"
Research has suggested that forms of dyslexia are caused by abnormal genes, but few genes have been identified. So Walsh honed in on a particular gene that causes a rare genetic disorder called periventricular nodular heterotopia (PNH), since patients with PNH also have a problem with reading fluency (trouble reading quickly and smoothly). He put together a study of PNH patients and used the latest imaging methods, including a specialized form of MRI called a diffusion tensor, to study their brain structures.
Comparing the MRIs of PNH patients to those of normal readers' brains, he found remarkable differences. Normal readers had organized nerve fibers connecting brain regions, whereas people with PNH had fibers that seemed to run helter-skelter. "Nerve fibers are a lot like electrical cables wrapped in insulation," says Walsh. "When you have a lot of them running in the same direction, it makes a coherent bundle. When they're running all over the place, they're disordered and tangled." Walsh thinks that the straighter organization of fibers is probably much more efficient, making it easier to process reading-related information.
His findings supported this idea, but Walsh is careful to note that this doesn't explain all fluency-based dyslexia. "We think that there might be different problems too—maybe with the way cells connect to one another or where the cells are located," he says. "But we do think that this wire organization issue is incredibly important in understanding more about the condition. Tying genetics to dyslexia allows us to identify a potential problem at birth, so that gives us the earliest possible chance to intervene. Doctors might make diagnoses using brain imaging, before reading even starts."
Nadine Gaab, PhD, a researcher in Children's Developmental Medicine Center Laboratory of Cognitive Neuroscience, is taking an alternative approach to studying dyslexia by focusing on how children process sounds and investigating whether musical training can improve reading. "It's a very neglected area in research," she says. "Many studies look at dyslexia's connection to the visual system but not the auditory." The idea that some dyslexics could have a problem processing sound was introduced in the 1970s, but it had never been tested using brain imaging. So Gaab decided to use functional MRI (which maps changes in the brain) to examine how the brains of 9- to 12-year-olds with dyslexia responded to sounds, before and after using educational software called Fast ForWord Language.
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Research shows that some dyslexics have problems telling the difference between fast-changing, similar sounds, like 'ba' and 'wa.' "They don't clearly hear these syllables, and that problem starts in infancy," says Gaab. "And if they miss that subtle change, it makes it much harder when they learn to read because they have to map these sounds onto written symbols. If the map is wrong and they link letters to the wrong sounds, it slows down development."
In studying her patients' brain scans, Gaab found significant differences in the way typical readers and dyslexic readers process these fast-changing sounds. Moreover, she found that daily sessions of sound training via Fast ForWord computer exercises can actually start to change the dyslexic children's brains, correcting the sound processing problem and improving their reading. "It shows that learning to listen helps to reshape parts of the brain's reading system," she says.
Gaab's findings relate to her longstanding interest in how music training influences reading and language development. Learning to sing or play an instrument, for example, involves gradual, repetitive and intense listening and responding to fast-changing sounds. Her parallel research projects are exploring this connection. One study focuses on children who attended music-oriented schools from age 2 to see if learning music at such an early age helped them tune into subtle changes in sound, and if they're better able to discriminate between syllables. A second study, in collaboration with MIT, uses a karaoke-style singing program: Adolescent dyslexics in Boston schools will have their brains scanned before and after an eight-week session of karaoke that tracks their pitch and timing. "We aren't interested in how well they sing," she says. "We want to see if their brains and reading levels change when the study is over."
A third study will focus on preschoolers whose family members have dyslexia. Gaab will test participants for auditory processing deficits and look for signs of the condition in the brain, then track the children's progress for two years. By looking for sound-processing problems before the children start to read, Gaab hopes to catch dyslexia at an early stage and treat it with sound training.
Early intervention is of paramount importance to both Walsh and Gaab because it could spare dyslexic children years of frustration. "These are smart kids who are really slow and inaccurate readers and grow to hate reading because of it," says Gaab. "Their peers tease them and call them stupid and their parents and teachers think they're lazy. And once children decide 'I can't do this,' it's a spiral downward." In fact, a number of studies show that dyslexic teens are much more likely to drop out of high school, get into trouble and get arrested.
But for Owen, who is now 12, having dyslexia has been more of an irony than a setback. He's always adored books and stories, even when he was younger and couldn't read at all. Back then, while his friends were running around and playing outside, he preferred to curl up with a book by himself, gleaning the gist of the story through its pictures. And while being dyslexic has certainly made reading and writing laborious—he still struggles to physically put words on paper and spell them correctly, always mixing up his Bs and Ds—Owen has never wavered from his determination to read. "He even walks home from school reading a book," Pat says. "Sometimes I actually have to stop him from reading." Ripley's Believe It or Not! is never out of his reach and he blew through four books on a recent vacation. "I don't know how much harder it is for me compared to normal kids because I've never been one," Owen says. "But I worked very hard and tried to read every day." His motivation was simple. "It was always nice when people read to me, so I wanted to read myself."
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