Fig. 3

Effect of tDCS on working memory (WM). a Reaction times (RT) during anodal tDCS. Anodal tDCS significantly reduced RT in the 2-back task with or without pain, compared with pre-tDCS baseline values, while no difference was observed for the 0-back task with or without pain compared with pre-tDCS baseline values (both p > 0.5). b RT during sham tDCS. No significant effect was produced by sham tDCS for either task, with or without pain (all p > 0.4). c Response accuracy (RA) during anodal tDCS. Consistent with the reduction of RT, RA tended to improve with anodal tDCS in the 2-back with pain task compared with the pre-tDCS baseline value (p = 0.057), but no effect was observed for the other tasks (all p > 0.4). d RA during sham tDCS. Sham tDCS did not produce any significant change in RA for any task compared with their respective pre-tDCS baseline values (all p > 0.3). Error bars Standard error of the mean (SEM). Double asterisks indicate significant difference at p ≤ 0.01