Previous preliminary results are sufficiently impressive to suggest that tDCS stimulation does have the potential to improve motor function when that ability is trained during stimulation. In the proposed study, the investigation will assess whether walking sessions combined with tDCS lead to improvements in motor function: gait, articulation, eye gaze, and motor dexterity. In addition, the investigators wish to examine if such results can be replicated in people with other conditions, such as cortical basal syndrome, and Parkinson's disease.