Stroke patients are to be examined with transcranial magnetic stimulation (TMS) before and after a short training session. TMS will be used to demonstrate changes in cortical excitability (motor threshold) and intracortical inhibition and facilitation. The effect of methylphenidate on baseline TMS measures will be evaluated as well as the effect on training induced changes in TMS measures (by comparing baseline and posttraining measures). The patients will be trained on two separate occasions, to compare the effect of Methylphenidate to placebo.