Abstract
We have tested the hypothesis that predictive motor behaviour is abnormal in Parkinson's disease. In the first experiment elbow movements were performed to track a moving spot on an oscilloscope screen. The performance of 12 patients with Parkinson's disease and eight age-matched control subjects was measured when tracking a repeated pattern under two conditions. In the first condition subjects were not aware of the repetitive nature of the tracking task whilst in the second condition they were. For both groups tracking error and tracking lag were less when aware of the repetition. In the second experiment wrist movements were studied. Five age-matched controls were compared with five patients, studied on and off drugs. In this experiment the performance tracking a repeated pattern was compared to that tracking unpredictable patterns. Tracking lags were reduced to very low values (less than 20 ms) in response to the repeated pattern for both groups. This was true even when the patients were relatively immobile off drugs. We conclude that patients with Parkinson's disease are capable of predictive motor behaviour although such a strategy does not always confer as great an advantage in reducing tracking error in patients compared with control subjects.
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Selected References
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- Day B. L., Marsden C. D. Two strategies for learning a visually guided motor task. Percept Mot Skills. 1982 Dec;55(3 Pt 1):1003–1016. doi: 10.2466/pms.1982.55.3.1003. [DOI] [PubMed] [Google Scholar]
- Flowers K. A. Visual "closed-loop" and "open-loop" characteristics of voluntary movement in patients with Parkinsonism and intention tremor. Brain. 1976 Jun;99(2):269–310. doi: 10.1093/brain/99.2.269. [DOI] [PubMed] [Google Scholar]
- Hallett M., Khoshbin S. A physiological mechanism of bradykinesia. Brain. 1980 Jun;103(2):301–314. doi: 10.1093/brain/103.2.301. [DOI] [PubMed] [Google Scholar]
- Marsden C. D. Function of the basal ganglia as revealed by cognitive and motor disorders in Parkinson's disease. Can J Neurol Sci. 1984 Feb;11(1 Suppl):129–135. doi: 10.1017/s031716710004628x. [DOI] [PubMed] [Google Scholar]
- Marsden C. D. The mysterious motor function of the basal ganglia: the Robert Wartenberg Lecture. Neurology. 1982 May;32(5):514–539. doi: 10.1212/wnl.32.5.514. [DOI] [PubMed] [Google Scholar]