Multiscale entropy curves (mean ± SE) of postural sway under single- and dual-task conditions, prior to the administration of tDCS. Curves have been averaged across the two baseline assessments; that is, before sham and real stimulation. Error bars represent 1 SE from the mean at each scale within each condition. It can be observed that postural sway complexity (Ci), as indicated by the area under the MSE curve, was lower in dual-task conditions as compared to single-task conditions (F1,78 = 4.58, p = 0.04)