A neurocomputational account of cognitive deficits in Parkinson's disease.
Parkinson's disease (PD) is caused by the accelerated death of dopamine (DA) producing neurons. Numerous studies documenting cognitive deficits of PD patients have revealed impairments in a variety of tasks related to memory, learning, visuospatial skills, and attention. While there have been several studies documenting cognitive deficits of PD patients, very few computational models have been proposed. In this article, we use the COVIS model of category learning to simulate DA depletion and show that the model suffers from cognitive symptoms similar to those of human participants affected by PD. Specifically, DA depletion in COVIS produced deficits in rule-based categorization, non-linear information-integration categorization, probabilistic classification, rule maintenance, and rule switching. These were observed by simulating results from younger controls, older controls, PD patients, and severe PD patients in five well-known tasks. Differential performance among the different age groups and clinical populations was modeled simply by changing the amount of DA available in the model. This suggests that COVIS may not only be an adequate model of the simulated tasks and phenomena but also more generally of the role of DA in these tasks and phenomena.
Purdue University, West Lafayette, IN 47907, USA.
Sébastien
S
Hélie
Erick J
EJ
Paul
F Gregory
FG
Ashby
D000375:Aging / Q000523:psychology; D000465:Algorithms; D001921:Brain / Q000503:physiopathology; D003072:Cognition Disorders / Q000209:etiology* / Q000523:psychology*; D003198:Computer Simulation; D004298:Dopamine / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology; D016014:Linear Models; D008959:Models, Neurological; D015233:Models, Statistical; D009483:Neuropsychological Tests; D017711:Nonlinear Dynamics; D010300:Parkinson Disease / Q000150:complications* / Q000523:psychology*; D011597:Psychomotor Performance / Q000502:physiology; D014887:Weather
D004298:Dopamine