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A-107: Cognitive and Neurobiological Mechanisms in Reading Disability
(Kenneth Pugh, PI)

Research Goals. Converging evidence from neuroimaging studies suggests that skilled reading is related to the development of a highly organized integration of orthographic, phonological and lexical-semantic features of words involving two consolidated left hemisphere (LH) posterior reading circuits: a dorsal (temporo-parietal) circuit and a ventral (occipito-temporal) circuit. These posterior reading circuits are dysfunctional in reading disabled (RD) readers. In apparent compensation for this LH posterior anomaly RD readers show 1) increased reliance on inferior frontal gyrus (IFG) during reading and 2) an increased tendency to engage the RH homologues of the disrupted LH posterior circuits. Using both fMRI and behavioral measures, Ken Pugh and colleagues are examining whether, in RD children, the compensatory reliance on inferior frontal gyrus (IFG) and RH posterior areas reflects a processing dissociation between phonological and semantic dimensions at the level of functional brain organization. Confirmation of this dissociation account using both fMRI and behavioral measures will provide a foundation for better understanding the specific deficits evident in RD children during word and pseudoword reading and a framework for interpreting changes in functional organization associated with development and/or remediation.

Current Status. The grant was funded beginning June 28, 2001 for five years through the Yale Medical School. Haskins is reimbursed for its grant related expenses and we receive indirect costs on the salary of one of the investigators.

[This project is supported by the National Institute of Child Health and Human Development (NIH Grant HD-40411). ]