MEMORY AND SKILL ACQUISITION IN PARKINSONS-DISEASE AND FRONTAL-LOBE DYSFUNCTION

Animal experiments and human neuropsychological studies have provided evidence for the hypothesis that skill acquisition may be regulated by the basal ganglia. In the present studies, perceptual and cognitive s kill acquisition as well as a number of explicit verbal memory functio ns were investigated in patients in early and more advanced stages of Parkinson's disease (PD) and in patients with frontal lobe lesions. Pa tients in more advanced stages of PD were impaired at cognitive skill acquisition as well as during recall conditions that involved active s emantic organisation of the stimulus material. Similar explicit memory deficits were present in frontally lesioned patients. PD patients wit h unilateral symptoms showed a selective impairment in acquiring a cog nitive skill. Perceptual skill acquisition was preserved in all groups . The overall pattern of memory impairment in PD is largely consistent with dysfunction of fronto-striatal circuitry.