Neurostimulation groups
Each participant was randomly assigned to either an active (n = 26) or sham (n = 23) tDCS stimulation group for the duration of the study at the time of their enrolment. All participants were blinded to the condition they were assigned to, as was the experimenter responsible for administering the testing and training sessions. Participants in both neurostimulation groups wore a custom headset (HALO Neuroscience™) designed to deliver transcranial Direct Current Stimulation (tDCS) to the cortical neurons of the M1 area responsible for controlling hand and arm movementParticipants in the active (STIM) neurostimulation group received 2.1 mA of bihemispheric stimulation (anode over left M1 and cathode over right M1) for a duration of 20 min whereas participants in the sham (SHAM) neurostimulation group received current that ramped from 0 to 1 mA and then back to 0 mA over two 30 s intervals before remaining at 0 mA for the following 19 min. This sham stimulation protocol has been demonstrated previously to not affect the long-term excitability of the underlying cortical neurons