Brain Activity During Production of Movement

This study will use electroencephalography (EEG) to examine how the brain prepares for movement. It will look at 1) what changes occur in a person's brain just before voluntary movement, 2) when the changes occur, 3) how consistent the changes are, and 4) how the changes vary from person to person. The information from this study will be applied to other studies, such as exploring how brain changes that signal movement can be used to control prostheses in patients with spinal cord injuries or stroke. Healthy normal volunteers 18 years of age and older may be eligible for this study. People with neurologic or psychiatric disorders and people taking medicines that may affect brain signals (e.g., Valium) may not participate. Participants will come to the NIH Clinical Center on two separate days for testing sessions of 2 to 3 hours each. At each session, an EEG cap will be placed on the head to record brain signals, and electrodes will be placed on the arms to record movement. Subjects will perform simple movements during the EEG recording, such as flexing their arm of clenching their fist. Researchers will use the first recording to determine the pattern of how the brain prepares for movement. During the second recording, they will try to predict the subjects' movements, based on the patterns discerned in the first recording.