Figure 1.

(A) In traditional tACS, the position of the electrode is determined by the location of the stimulation. (B) HD-tACS; blue regions are the anodes, and the black region is the cathode. (C) Phase-shifted tACS; blue regions are the anodes, and the black region is the common cathode; the stimuli exerted by the two blue electrodes are only different in phase. (D) AM-tACS; blue regions are the anodes and the black region is the common cathode; the stimuli exerted by the two blue electrodes are, respectively, the envelope wave and the modulated wave. (E) Temporally interfering (TI) stimulation; the blue and black regions are two pairs of electrodes with different high-frequency electrical stimulations. (F) Intersectional short pulse (ISP) stimulation; a pair of electrodes at both ends of each arrow, and the stimulation time of each pair of electrodes is different.