RecruitingDevice studyTreatment of Cognitive and Sensorimotor Deficits in Parkinson's Disease With High Definition Transcranial Direct Current StimulationThe purpose of this research study is to examine the effects of transcranial Direct Current Stimulation (tDCS) on verbal retrieval and cognition and sensorimotor control and to determine if tDCS can be used as a way to improve retrieval, sensory, and motor abilities in individuals with Parkinson's disease (PD).