Imagine seeing the word "dog" but your brain reads it as "god". Imagine trying to read, and finding it hard to connect the squiggles on the page with the sound of the word.
"Frustration is a part of the daily life of a dyslexic," says J. Thomas Viall, executive director of The International Dyslexia Association.
Is it a physiological or psychological problem, however?
Most people would say the former and be surprised to hear this has never really been proven. Up till now.
A new study published in Proceedings of the National Academy of Sciences offers visual evidence through functional magnetic resonance imaging (fMRI) that dyslexia is caused by a functional disruption in the brain.
While neuroscientist Samuel Orton first theorized in the 1930s that reading disability is a brain-based disorder, previous imaging studies were unable to reveal the extent of the disruption. The current research, led by Dr. Sally Shaywitz, professor of pediatrics at the Yale University School of Medicine, imaged the brain activity patterns of 32 non-dyslexic and 29 dyslexic adults as they categorized words and performed rhyming and letter recognition exercises. In the dyslexic reader, the fMRI indicated a pattern of underactivation in the brain region that connects the visual areas with the language areas. The disruption between these two critical areas needed for reading inhibits the dyslexic reader to associate the letters in the printed word with the sound it represents.
"It isn't that they don't see the letters properly or hear the sounds. The image of the letter gets to the brain perfectly well, but the brain doesn't process the information in the way non-dyslexics process it, and therefore the dyslexic reader has trouble making the connection," explains Viall.
Most notable was the detection of underactivation in the angular gyrus region of the brain in dyslexic readers. Previous studies have shown that individuals who suffer brain damage in that same area also lose reading ability.
"This research offers hope of increased public awareness of learning disorders as a 'real' disability, not laziness, retardation, an 'eye problem', or a hearing problem," says Dr. Sheldon Horowitz, director of professional services at the National Center for Learning Disabilities in New York.
"It helps us to understand the biological nature of a particular type of reading disorder, and poses enormous promise in the ways it might inform teaching practice," he continues. "The research suggests in a very powerful way that there is a critical foundation for reading that must be taught, practiced, and supported for individuals to be competent readers. The study and the work that will follow points to the critical role of phonic awareness in the reading process, and suggests that teaching curricula should focus on mastering these skills, as they are so important to setting the stage for a lifetime of literacy."
Viall at The International Dyslexia Society concurs. "There has been for some time a growing body of evidence regarding the neurobiological causes of dyslexia. From the earliest theories, we have been developing a clearer picture of the real differences between dyslexic and non-dyslexic brains."
He contends it is difficult to predict whether the new research will help in terms of diagnosis. "Where it does help is to prove it's a real disorder," he says, stressing that often the psychological impact of not being able to read is underestimated. "Too many people think the individual is lazy or dumb ... sometimes the prejudices are the more important things to get over."