 Transcranial direct current stimulation tDCS is a safe method to induce weak transcranial currents up to 1-2 milliampere. Using 2 rubber electrodes positioned on the scalp, tDCS can be used to manipulate localized brain excitability via membrane polarisation: cathodal stimulation hyperpolarises, while anodal stimulation depolarises the resting membrane potential, whereby the induced after-effects depend on polarity, duration and intensity of the stimulation. 