Right hemisphere activation in recovery from aphasia

Lesion effect or function recruitment?

G. Raboyeau, PhD, X. De Boissezon, MD, PhD, N. Marie, MD, S. Balduyck, MD, M. Puel, MD, C. Bézy, BA, J. F. Démonet, MD, PhD and D. Cardebat, PhD

From Pôle Neurosciences CHU Toulouse (G.R., X.D.B., N.M., M.P., C.B., J.F.D., D.C.), Inserm UMR S825, IFR 96, Universités de Toulouse; Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (G.R.), Canada; and PET Center (S.B.), Purpan Hospital, Toulouse, France.

Address correspondence and reprint requests to Dr. G. Raboyeau, 4545 Chemin, Queen Mary Montréal (Québec) H3W 1W5, Canada gaelle.raboyeau@criugm.rtss.qc.ca

Background: Some neuroimaging studies have suggested that specific right hemispheric regions can compensate deficits induced by left hemispheric lesions in vascular aphasia. In particular, the right inferior frontal cortex might take part in lexical retrieval in patients presenting left-sided lesions involving the homologous area.

Objective: To address whether the involvement of the right inferior frontal cortex is either unique to recovering aphasic patients or present also in other circumstances of enrichment of lexical abilities, i.e., in non–brain-damaged subjects over learning of new vocabulary.