Reading and Sensorimotor Fluency in Dyslexia

Impaired reading fluency, the ability to read text rapidly, smoothly, and effortlessly, is one of the more prominent behavioral manifestations of dyslexia. While dyslexia is largely associated with language dysfunction, there is possible evidence that sensory and sensorimotor processing failures exist as well. In this project, behavioral and fMRI measures are being used to investigate how reading fluency relates to mechanisms involving reading, rapid automatized naming, phonological processing, speeded motor performance, and visual motion processing. The central hypothesis proposes that in dyslexia, a disorder in temporal information processing exhibits itself as deficits in these mechanisms. In previous studies, we have found a sensory deficit in dyslexia that is specific to the visual motion processing system. We are now exploring the functional neuroanatomy of speeded motor performance and investigating the relationship between motor control abnormalities and reading fluency deficits. A particular emphasis in the research is to identify to what degree are the systems responsible for reading, rapid automatized naming, phonological processing, speeded motor performance, and visual motion processing share common neural substrates. This project will provide new information concerning the neural organization of reading in health and in disease. Findings may suggest innovative approaches to the diagnosis and treatment of developmental dyslexia.

(Funding Source: NICHD)