Figure 2.

Changes in MEP amplitude (A,C) and in the contralateral silent period (SP) duration (B,D) in response to a-tDCS. In (A,C) changes are shown for each individual as a ratio of the grand average computed for all time points post-tDCS divided by baseline (i.e., post-tDCS/BL). The dotted lines in each graph indicate no change relative to baseline. Note that the missing data (A) refers to an outlier (participants #5) whose MEP data had to be removed from the analysis. In (B,D) the overall changes are shown as means and standard deviations computed across all participants and for each time point before (BL) and after a-tDCS. Note the relatively large variability observed between individuals for modulation in MEP amplitude (A) and in cSP duration (C).