Brain basis for dyslexia: a summary of work in progress

Studies of brain/behavior relations in the last decade have converged to suggest a left-hemisphere functional deficit for dyslexia. The relationship is most convincing at the microscopic level, where anomalous neural organization has been associated with reading, and at the macroscopic level, where several studies find atypical hemispheric symmetry in the language-related temporal region in individuals with dyslexia. Physiological studies measuring brain function during cognitive challenge have now begun to accumulate in support of a left-hemisphere deficit in dyslexia. This article summarizes work in progress on the structure and physiological profiles of reading disability and relates the findings to core left-hemisphere language functions.