Fig. 1

Schematic of active tDCS (solid red line) and placebo stimulation (dashed black line). For both active and placebo stimulation, current was ramped up over 8 s to 1 mA (blue shaded areas). Active stimulation remained at this level for 1200 s (20 min) followed by fade-out over 8 s from 1 to 0 mA. Placebo stimulation remained stable at 1 mA for only 40 s before fade-out over 8 s