Probabilistic learning and reversal deficits in patients with Parkinson's disease or frontal or temporal lobe lesions: possible adverse effects of dopaminergic medication.

Journal article

Three groups of patients with Parkinson's disease (PD) - mild, unmedicated (UPD), mild, medicated (MPD) and severe, medicated (SPD) - and patients with lesions of the frontal lobe (FLL) or temporal lobe (TLL) were compared with matched controls on the learning and reversal of probabilistic and two-pair concurrent colour discriminations. Both of the cortical lesion groups showed reversal deficits, with no increase in perseverative responding. The UPD group, although impaired on a spatial recognition task, showed intact discrimination learning and reversal; the MPD and SPD patients showed non-perseverative reversal impairments on both reversal tasks. Two hypotheses - based on disease severity and possible deleterious effects of medication - are offered to explain the reversal impairments of the PD patients and the results are discussed in terms of the role of dopamine in reward-based learning.

Authors: Swainson, R; Rogers, R; Sahakian, B; Summers, B; Polkey, C

• Publication status: Published
• Journal: Neuropsychologia
• Volume: 38
• Issue: 5
• Pages: 596-612
• Publication date: 2000-01-01
• DOI: 10.1016/s0028-3932(99)00103-7
• EISSN: 1873-3514
• ISSN: 0028-3932
• Language: English
• Keywords: Humans; Parkinson Disease; Pattern Recognition, Visual; Adult; Antiparkinson Agents; Visual Perception; Space Perception; Epilepsy; Levodopa; Frontal Lobe; Neostriatum; Temporal Lobe; Reversal Learning; Female; Learning Disorders; Male; Discrimination (Psychology); Models, Statistical