Figure 5

Effects of tDCS on spectral and MSE measures in stroke patients. Post vs. pre-stimulation differences are presented on the y-axis, separated by stimulation conditions (A) and Hard vs. Easy versions of the repetition task (B) on the x-axis. (A) A significant two-way interaction between stimulation sites (left, right) and stimulation conditions (sham vs. anodal-tDCS) was found for coarse-scale MSE and theta. Larger reductions in these measures were found in the right site after left anodal-tDCS. (B) Significant three-way interaction was found for anodal-tDCS among the stimulation sites (left, right), conditions (sham vs. anodal-tDCS) and training task version (Hard, Easy) for fine-scale MSE and low-gamma. Increases in these meaures were found in the left stimulation site in the Hard group after anodal tDCS. Two-way interaction between sites (left, right) and stimulation conditions (cathodal-tDCS vs. sham) was also found, which revealed increases in fine-scale MSE in the left site after cathodal-tDCS compared to sham-tDCS across both Easy and Hard groups. Error bars indicate SE. Asterisks (*) indicate significance at p < 0.05 from linear mixed models; refer to the text for more details. (C) Scatter plot indicating a relationship between changes in repetition accuracy and theta power changes after anodal-tDCS with respect to sham-tDCS for left and right stimulation sites.