(a) Visual graphs of SCR data processing. Graphs visually show any possible changes in participants’ SCRs in the two experimental conditions, before and during tACS stimulations, for all image categories (UHA, ULA, PHA, and PLA). (b) The main effect of pleasantness in physiological data (i.e. SCR): we can only observe a difference in participants’ physiological responses between pleasant images (PHA and PLA) compared to unpleasant images (UHA and ULA).