Conventional tDCS, utilizing large electrode congurations, leads to the activa­tion of relatively extensive cortical regions. A fraction of the electrical current is diverted by the scalp, while the remaining portion effectively reaches the brain tis­sue and elicits diffuse alterations in cortical excitability. To address the limited spa­tial resolution of conventional tDCS, several methods have been proposed to enhance stimulation focus. In 2009, a novel electrode conguration known as high­denition tDCS (HD-tDCS) was developed with the aim of improving stimulation focality and enabling precise targeting of specic brain regions [12]. In contrast to conventional tDCS, which typically employs two larger electrodes, HD-tDCS uti­lizes multiple smaller electrodes (approximately 1cm2) for enhanced spatial target­ing. Moreover, the position and current intensity at each electrode can be optimized to improve precision or targeting [5, 7, 13]. Smaller electrodes offer the advantage of accommodating a larger number of electrodes and/or positioning them in closer proximity [14]. A commonly employed electrode conguration for HD tDCS is a 4×1 ring, consisting of a central electrode surrounded by four polarity-opposite peripheral electrodes [13]. In comparison to conventional tDCS, the 4×1 ring­shaped HD-tDCS elicits a more localized brain stimulation, conning the induced modulation of cortical excitability within the boundaries of the ring electrode. The concentration of the electric eld’s peak within the central electrode area enhances stimulation precision and current intensity, ensuring a high current density in the target region while minimizing undesired effects on nontarget brain areas [13, 15]. In addition to enhanced focality, the effects of HD-tDCS on cortical excitability persist for a minimum duration of 30 min longer than those observed with