Effect of Stimulus Rate on Cognitive and Motor Activity in Young Subjects, Elderly Subjects, and Patients With Parkinson's Disease

Study Summary

The purpose of this study is to investigate how changes in the brain associated with Parkinson's disease influence the control of motor and thinking speed. There is disagreement over whether patients with Parkinson's disease are slow in thinking as well as movement. This study may provide a new framework to explain the relationship between motor and cognitive aspects of human behavior and help to clarify the pathophysiology of Parkinson's disease. There are two parts to the study: behavioral tests and functional magnetic resonance imaging (fMRI). All participants will be asked about their medical history, have a physical examination, and complete a questionnaire. They must not take regular medications, including levodopa and dopamine agonists, for 8 hours prior to the study. The behavioral study involves computer-generated neuropsychological tasks, including hand movements, imagination of movements, and mental calculations. Response will be recorded and evaluated. Electrodes may be placed on the participant's skin to measure surface electromyogram (EMG). The fMRI study involves MRI scanning in which motor and thinking tasks are performed. Electrodes may be placed on the skin to monitor muscle activity. Thirty patients, ages 40 and up, with early-stage Parkinson's disease will be recruited. Sixty normal volunteers ages 21-75 will be included as well for comparison.