This protocol will characterize the effects of deep brain stimulation (DBS) location (both adverse and beneficial) on motor signs in people with Parkinson's disease (PD). This information can be used to inform future DBS protocols to tailor stimulation to the specific needs of a patient. If targeted dorsal GP stimulation is shown to significantly improve motor features that are typically resistant to dopamine replacement therapy, these experiments will likely have major impact on clinical practice by providing a potential strategy to these medically intractable symptoms.