A current up to 1.5mA current will be delivered using surface rubber-carbon electrodes (35cm2) with surrounding saline soaked sponges (0.9% NaCl) by a battery driven, constant current stimulator (maximum output 2mA). Participants will receive stimulation for 20 minutes while seated (before robotic motor training), with the anode over the optimal site for first dorsal interosseous (FDI) as identified using TMS, and the cathode on the contralateral supraorbital area. Sham tDCS: comparable set-up to real tDCS, 30 sec real current ramping to current up to 1.5mA at commencement, then after 5 sec a slow decrease but to no current sustained for 20mins.