Abstract
Three groups of patients with Parkinson's disease (PD) - mild, unmedicated (UPD), mild, medicated (MPD) and severe, medicated (SPT) - 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 ic 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. (C) 2000 Elsevier Science Ltd. All rights reserved.
Original language | English |
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Pages (from-to) | 596-612 |
Number of pages | 17 |
Journal | Neuropsychologia |
Volume | 38 |
Issue number | 5 |
Publication status | Published - 2000 |
Keywords
- visual discrimination
- concurrent
- dopamine
- reward
- cortical
- SPATIAL WORKING-MEMORY
- PREFRONTAL CORTEX
- EXCITOTOXIC LESIONS
- BASAL GANGLIA
- VISUAL-DISCRIMINATION
- INFEROTEMPORAL CORTEX
- HUNTINGTONS-DISEASE
- VISUOSPATIAL MEMORY
- PERFORMANCE
- LEVODOPA