 Participants will continue taking their regular medications, and treatments will take place in the ON medication state approximately at the same time of day for each treatment. The real tDCS intervention will simultaneously target both the M1 leg area and the the dorsolateral prefrontal cortex DLPFC, in the brain hemisphere contralateral to the more affected side of the body, as determined by the summation of the motor symptoms on The unified Parkinsons disease rating scale UPDRS. Current will be applied using an array of 8 sponge electrodes and the StarStim tDCS device and software Neuroelectrics, Inc. For this protocol, the placement and current delivered through each electrode has been optimized using the Neuroelectrics StimWeaver Stimulation Optimization Service . In case of bilateral symptom symmetry, tDCS will target the left M1 and DLPFC. For the sham intervention, the same electrode placement and stimulation parameters will be used; however, current will only be applied for the first 60 seconds of the stimulation session. This is a reliable control as sensations arising from tDCS diminish considerably after the first minute of stimulation. At the end of each treatment session, participants will complete a short questionnaire to assess potential side-effects. At the end of the entire intervention, participants will be asked to state if, in their opinion, they received the real or sham intervention. 