Rhythm Perception and Generation

This study will examine how different brain areas are involved in the perception of rhythmic patterns and the performance of rhythmic movements. Patients with certain types of brain diseases, such as Parkinson's disease and some types of stroke, may have difficulty performing rhythmic movements, such as finger tapping. Healthy, right-handed volunteers between 21 and 65 years of age may be eligible for this study. Candidates with visual, motor or hearing problems are excluded, as are musicians and pregnant women. Participants will come to the National Institutes of Health (NIH) Clinical Center for up to six sessions of functional magnetic resonance imaging (fMRI) scanning. MRI uses a strong magnetic field and radio waves to obtain images of body organs and tissues. The scanner is a metal cylinder surrounded by a magnetic field. During the MRI, the subject lies still for up to 20 minutes at a time on a table in the cylinder and wears earplugs to muffle loud knocking noises that occur with the electrical switching of the magnetic fields. He or she can communicate with the MRI staff through a microphone at all times during the procedure. For fMRI, images are obtained while the subject performs a task, such as hearing sounds or moving a finger. The machine detects changes in brain movement that are involved in performing the task. The tasks are explained, and subjects can practice them before entering the scanner.