May 1, 2008 — Cognitive neuroscientists monitoring brain activity with fMRI found that children with dyslexia are often unable to process the fast-changing sounds used in spoken language. Sound training dedicated to teaching children to better process these sounds improves their ability to manipulate words and their phonetic components, which translates into better reading
Dyslexia can be a frustrating condition, making it difficult for children to read. Many think it is a visual issue, but a new study using a computer game reveals the problem may not only be with sight, but also sound.
Jake Lo Giudice is dyslexic and some words can be tough to identify. "I felt like I was different," Jake recalls. I felt like I was outside of the group." Jake's mother Karen uses clay models to help her son visualize non-sight words. "It's because they are picture thinkers and those words do not have a picture," Karen explained. But researchers believe the problem could also be with how the brain "hears" sounds. "We believe that these children -- from being toddlers or even earlier as infants -- have problems with processing these changes in sounds," Nadine Gaab, Ph.D., an assistant professor of pediatrics at the Children's Hospital in Boston, Mass., told Ivanhoe.
Cognitive neuroscientists believe dyslexic children's brains have problems interpreting fast-changing syllables like "ba" and "da" because their brains are wired differently. This makes reading more of a challenge. Dr. Gaab is using "sound training" through computer exercises to monitor how dyslexics process fast and slow-changing sounds. While children play the game, Dr. Gaab monitors their brain activity using functional magnetic resonance imaging (fMRI). But after eight weeks of intensive training, a dyslexic child's fMRI image shows more activity. "The brain is very plastic and so the brain learns and reconnected and built a new network," Dr. Gaab explained.
That possible reconnection could hold the key to helping dyslexics read. Researchers hope as children are diagnosed with dyslexia earlier, they can start sound training sooner and possibly reduce the severity of their condition.
LANGUAGE PROCESSING IS THE KEY: It is worth noting that dyslexia is not clinically identified by seeing letters backward or out of order. When dyslexics hear speech, they are not necessarily able to hear the sound accurately. Recent research showed that the brains of children with dyslexia are not able to process fast-changing sounds. Based on data obtained via fMRI, the findings suggest new ways to treat dyslexia and may help doctors to diagnose the disability earlier in life, before reading begins. This causes problems later when kids attempt to sound out words while reading.
THE EXPERIMENT: Researchers agree that dyslexics have problems manipulating words and sounds – that the primary problem is processing the sounds that make up words. Using a computer program that plays fast-changing and slow-changing sounds, Dr. Gaab used fMRI to monitor how children's brains respond to the sounds. Children with dyslexia use the same brain areas to process both fast and slow changing sounds, as opposed to other readers, who use a certain array of 11 areas more extensively when processing fast-changing sounds.
WHAT IS fMRI? Magnetic resonance imaging (MRI) uses radio waves and a strong magnetic field rather than X-rays to take clear and detailed pictures of internal organs and tissues. fMRI uses this technology to identify regions of the brain where blood vessels are expanding, chemical changes are taking place, or extra oxygen is being delivered. These are indications that a particular part of the brain is processing information and giving commands to the body. As a patient performs a particular task, the metabolism will increase in the brain area responsible for that task, changing the signal in the image. Analyzing the images to understand how responses are similar or different for different tasks allows scientists to better understand the patient as an individual, and also to learn more about the human brain in general.
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