EFFECTS OF LEFT BASAL GANGLIA LESIONS ON LANGUAGE PRODUCTION

Three patients with lesions mainly confined to the left basal ganglia were studied with a series of neuropsychological and neurolinguistic r ests. Two patients were nonfluent, whereas one presented with fluent s pontaneous speech. AU of them produced agrammatic sentences and lexica l and semantic mistakes. Perseverations and echolalias were two furthe r characteristic disorders of their speech production. The linguistic symptoms observed in these three patients suggest that the left basal ganglia play an important role (a) in regulating arousal and speech in itiation, (b) in monitoring the semantic and lexical aspects of langua ge, and (c) in switching from one linguistic element to the following during language production.