Use of Transcranial Direct Current Stimulation (tDCS) Coupled With Constraint Induced Movement Therapy in Stroke Patient

In this 3 experiments study we will evaluate the effect of tDCS and constraint induced movement therapy (CIMT) in stroke patients (exp 1) as well as in healthy subjects (control population - exp 2). Finally we will investigate the effect of tACS - transcranial alternating current stimulation - as an alternative to tDCS, on motor function in healthy subjects (exp 3). The two experiments on tDCS are parallels (exp 1 \& 2), while the experiment on tACS uses a crossover design (exp 3). For stroke patients (Exp1), our primary outcome measure is a clinical scale (Jebsen-Taylor Hand Function Test), while for healthy subjects (Exp 2) we investigate the effect of tDCS and CIMIT on cortico-spinal excitability using TMS - transcranial magnetic stimulation. Finally, for the third experiment using tACS, our primary outcome is cortical oscillation, as measured by EEG - electroencephalogram.