Academic achievement and attention-deficit/hyperactivity disorder in children with left- or right-hemisphere dysfunction.

The neuropsychological investigation of learning disabilities has contributed much toward a more complete understanding of how the hemispheres are functionally organized and how differences in this functional organization may affect differential patterns of learning and behavior. It has been suggested that right-hemisphere dysfunction increases the likelihood of difficulty with attention/concentration and of overactive behavior, and interferes with arithmetic calculation more readily than reading and spelling. The present study examined the influence of right-versus left-hemisphere neuropsychological dysfunction on academic achievement and attention using two groups of children with learning disabilities and a group of nondisabled children. Results provide limited support for the hypothesis that the right hemisphere subserves attention and concentration. No support was found for the hypothesis that right-hemisphere deficits are more frequently associated with deficient arithmetic calculation, as opposed to reading and spelling performance. Results are discussed in the context of previous research on right-hemisphere dysfunction and learning disabilities.