Deep brain stimulation is currently used to treat a variety of movement disorders, such as Parkinson's disease and certain tremors. A wire is placed into deep structures of the brain, and stimulation is given at fixed settings. This project would allow for placement of additional sensors, on the surface of the brain, to record signals associated with movement, or intent to move. These signals would be used to trigger the stimulation of the deep structures, instead of a constant setting. By recording the signals during movement, specific types of signals will be identified that best help control tremor. The ability of the individual patient to use this flexibility to control tremor will be explored.