Interval timing and Parkinson’s disease: heterogeneity in temporal performance

• Published in: Experimental brain research Vol. 184; no. 2; pp. 233 - 248
• Main Authors: Merchant, Hugo, Luciana, Monica, Hooper, Catalina, Majestic, Stacy, Tuite, Paul
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.01.2008; Springer; Springer Nature B.V
• Subjects: Adult; Aged; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Brain - drug effects; Brain - metabolism; Brain - physiopathology; Cognition - drug effects; Cognition - physiology; Cognition Disorders - drug therapy; Cognition Disorders - etiology; Cognition Disorders - physiopathology; Cortical Synchronization - drug effects; Decision Making - drug effects; Decision Making - physiology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Disability Evaluation; Dopamine - deficiency; Dopamine Agonists - pharmacology; Dopamine Agonists - therapeutic use; Female; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Male; Medical sciences; Memory Disorders - drug therapy; Memory Disorders - etiology; Memory Disorders - physiopathology; Middle Aged; Neural Pathways - drug effects; Neural Pathways - metabolism; Neural Pathways - physiopathology; Neurology; Neuropsychological Tests; Neurosciences; Parkinson Disease - drug therapy; Parkinson Disease - physiopathology; Parkinson Disease - psychology; Parkinson's disease; Perceptual Disorders - etiology; Perceptual Disorders - physiopathology; Research Article; Time Perception - drug effects; Time Perception - physiology; Traumas. Diseases due to physical agents; Interval timing; Heterogeneity of Parkinson’s disease; Time production; Parkinson’s disease; Time perception; Human; Nervous system diseases; Parkinson's disease; Decision making; Deficiency; Memory; Parkinson disease; Cerebral disorder; Central nervous system disease; Tapping task; Degenerative disease; Timing; Time analysis; Categorization; Heterogeneity of Parkinson's disease; Extrapyramidal syndrome
• ISSN: 0014-4819; 1432-1106; 1432-1106
• DOI: 10.1007/s00221-007-1097-7

Interval timing deficiencies in Parkinson’s disease (PD) patients have been a matter of debate. Here we test the possibility of PD heterogeneity as a source for this discrepancy. Temporal performance of PD patients and control subjects was assessed during two interval tapping tasks and during a categorization task of time intervals. These tasks involved temporal processing of intervals in the hundreds of milliseconds range; however, they also covered a wide range of behavioral contexts, differing in their perceptual, decision-making, memory, and execution requirements. The results showed the following significant findings. First, there were two clearly segregated subgroups of PD patients: one with high temporal variability in the three timing tasks, and another with a temporal variability that did not differ substantially from control subjects. In contrast, PD patients with high and low temporal variability showed similar perceptual, decision-making, memory, and execution performance in a set of control tasks. Second, a slope analysis, designed to dissociate time-dependent from time-independent sources of variation, revealed that the increase in variability in this group of PD patients was mainly due to an increment in the variability associated with the timing mechanism. Third, while the control subjects showed significant correlations in performance variability across tasks, PD patients, and particularly those with high temporal variability, did not show such task correlations. Finally, the results showed that dopaminergic treatment restored the correlation effect in PD patients, producing a highly significant correlation between the inter-task variability. Altogether, these results indicate that a subpopulation of PD patients shows a strong disruption in temporal processing in the hundreds of milliseconds range. These findings are discussed in terms of the role of dopamine as a tuning element for the synchronization of temporal processing across different behavioral contexts in PD patients.