Transcranial direct current stimulation (tDCS): For tDCS a 5 cm2 sponge electrode (cathode) will be placed over the target area (Broca Area's homologue in the non-dominant hemisphere) and the anode on the forehead over the contralateral eye. A direct current of 2mA will be applied between electrodes. A negative current applied to the brain area under the cathode will cause a decrease in resting membrane potential of the underlying neurons thus reducing their excitability. tDCS will start immediately before the SLT session and last throughout the session. tDCS only evokes a tingling sensation on the skin when turned on and off. For sham stimulation the current will be turned on for 30 seconds to elicit a typical skin sensation and then turned off for the duration of the therapy. The same will be done at the end of the session.