tDCS stimulation parameters
Stimulation was delivered using the Eldith DC Stimulator Plus (NeuroConn GmbH, Ilmenau, Germany). The stimulation parameters including the electrode size, current intensity, stimulation duration, and sham protocol were chosen based on the most common settings in the literatureSimulation of normalized electric field distribution (|E|) for both montages. Field strengths were similar between electrode montages. For the anodal fronto-medial stimulation, the anode was applied over the AFz and the cathode over the Pz. For anodal stimulation of the left DLPFC, the anode was placed over the F3 according to the international 10–20 EEG localization system, while the cathode was positioned over the contralateral supraorbital area. When applying cathodal stimulation, the position of the anode and cathode electrodes was reversed.