Recent research led by Guinevere Eden, director of the Center for the Study of Learning at Georgetown University Medical Center, has cast serious doubts on the theory that dyslexia stems from deficits in the visual system. She contends that dyslexia is not a problem of seeing, but a problem of processing language and assembling individual sounds into words. Nevertheless, it is true that visual deficits are consistently found in dyslexics. Researchers like Eden have advanced a theory for this that may reveal the workings of both dyslexia and normal reading.

Dyslexia and Deficits in the Visual System: A New Theory

Image source: The New York Times


Researcher Olumide Olulade, also at Georgetown, notes that reading is not a culturally imposed skill. Humans did not evolve to read, but rather evolved to understand and produce spoken language. Literate humans then had to change their brain significantly to turn written letters into meaningful symbols, and the more they read the more their brains change. In children with dyslexia, however, the initial stages of this brain change do not proceed as in other children’s brains.

Bart Boets of the Catholic University of Leuven in Belgium says that dyslexia is a “disconnection syndrome.” He proposes that the brains of dyslexics do form accurate neurological representations of language sounds, which explains why dyslexics have no problems with spoken language. When dyslexics go to put together these sounds into words, communication between the auditory and language centers of the brain seem to break down. This disconnection makes reading difficult from the very beginning. Because reading is so hard, dyslexic children may do it less and because they read less, their brains change less. Visual deficits, then, are not the cause of dyslexia but rather the result of less reading and experience.

An important implication of this research is that normal and dyslexic brains may not be as inherently different as once believed. Difference may actually be a product of experience. Eden believes that the right kind of experience such as intensive tutoring in phonological and orthographic skills can undo some of these differences and significantly improve dyslexic children’s reading skills.

Thus, dyslexic children should be encouraged to keep reading, even though it may be a struggle. These reading difficulties may not be hard-wired after all, but rather the result of experience.

To read more about this research, visit The New York Times.