<qa>  What is the opposite effect of tDCS?tDCS TDCS is an affordable and safe method of brain stimulation which can be broadly used in general population. In tDCS, the cerebral cortex is stimulated through a weak constant electric current 1-2 mA through two electrodes 35 cm2 and 70cm2, an active electrode which targets a special region of brain and a return electrode. This weak current can induce focal changes of cortical excitability that lasts beyond the period of stimulation. In general, Anodal stimulation A-tDCS is supposed to depolarize neurons leading to an increase in excitability, whereas Cathodal stimulation C-tDCS has the opposite effect compared to sham. Sham tDCS S-tDCS refers to a control condition in which the subject will receive a brief current but then the stimulator remains off for the rest of the stimulation time. In this way, the individuals receiving the S-tDCS are not aware that they are not receiving prolonged stimulation.The mechanisms of tDCS effect are classified into synaptic changes by altering the strength of synaptic transmission and non-synaptic shifts in resting membrane potential of pre and post-synaptic neurons. 