FMRI Studies of Phonological and Sensory Processing in Dyslexia

This is a series of integrated studies combining behavioral measures with functional magnetic resonance imaging (fMRI) to investigate the relationship between the disorders in phonological processing and visual motion processing in dyslexia. Our central hypothesis posits the existence of a disorder in temporal information processing in dyslexia that exhibits itself in deficits in both temporal and language processing. Specific questions addressed include: (1) What are the neural systems involved in phonological awareness (segmentation, rhyme generation and coding involved in verbal memory) and visual motion processing in normal subjects? (2) Do the neural systems involved in phonological awareness show sensitivity to performance rate, modality of presentation (oral versus visual) or response (covert versus overt)? (3) Is there spatial overlap in the neuronal systems involved in the performance of phonological awareness tasks and visual motion processing? (4) Since performance on these tasks reliably differentiates dyslexics from controls, are the neural systems involved differently activated in dyslexics and controls during the performance of these tasks?

(Funding Source: NICHD)