Guinevere Eden: International Advocate of Dyslexia Research and Support
While she finds that detail interesting, Eden is much more intrigued by brains that engage in reading tasks in ways that are unusual – even when only a single language is involved. For example, she has studied hyperlexia, a rare condition in which children as young as three can read precociously but who also can have delays in speaking and in understanding spoken words. Eden performed the first fMRI scans of children with hyperlexia to view activity within their brains.
It is, however, the other end of the spectrum – dyslexia – that captivates her. Eden sees the condition as a portal into understanding the brain-basis of development, learning and experience.
Dyslexia is not, as many people think, characterized by reading letters out of order, but is a weakness in the brain’s visual processing centers. Brain scans show under-activity in the back of the brain in dyslexics, but that does not mean these brains are abnormal, she says. Instead, dyslexia is an issue in how an “old” brain adapts to a new use.
“Reading is a purely cultural invention,” Eden says. “There is nothing in the brain that is specialized for reading, which, when considering human evolution, has only become important to us relatively recently. Using our brains to read has meant we have had to redirect usage of other brain systems.”
Eden began studying children with the condition in 1990 as a PhD candidate at Oxford University, which brought her to the National Institutes of Health in 1993 and then to GUMC in 1996. She is now president of The International Dyslexia Association, a group that promotes literacy through research, education, and advocacy. Her goal is to combine brain-based research with education designed to improve the reading skills of dyslexics. This so-called “educational neuroscience” approach uses fMRI to figure out which educational approaches work best, and why, and how they change the brain.
Dyslexia is seen worldwide, in people of all intelligence levels. It affects about 5-12 percent of the population, with the incidence in the US and UK likely to be on the higher side. “That’s because there are more exceptions to language rules in English than there are in other languages, such as German, and these provide additional challenges in learning to read,” she says.
Eden is struck by the complexities of the condition, such as the fact that up to 40 percent of people with dyslexia also are diagnosed with attention deficit hyperactivity disorder (ADHD). “That is so interesting, because ADHD involves areas in the front of the brain, while much of the research in dyslexia has focused on the back portions,” she says. Furthermore, although dyslexia has a strong genetic (heritable) component, its development can be influenced by environmental factors, such as instructional approaches.
Remarkably, cognitive training such as explicit tutoring can ameliorate the condition, and Eden’s research team can use brain-imaging technology to investigate which areas in the brain are responsible for reading gains. “We can scan both children and adults with dyslexia before and after an intervention and examine where the brain has changed,” she says. “We can see new activity in areas that weren’t very active before, and in some people, we can tell that the brain recruits a whole new area to help it read.
“Dyslexia may be common,” Eden says, “but there is nothing simple about it.”
By Renee Twombly, GUMC Communications