Behavioral results.

<p>a) The congruency sequence effect (CSE), showing RT on the current trial (C: congruent, I: incongruent) as a function of previous-trial congruency (c: previous congruent, i: previous incongruent). b) The CSE (defined as [cI–cC]–[iI–iC]) as a function of block (pre, stim, post) and frequency (red: theta, blue: alpha). c) Residual RT calculation. A linear model was fit to all RTs, and the distance from each RT to the linear least square line was taken as the residual RT. d) Left: the effect of tACS (defined as [stim–pre]–[post–pre] on residual RT) plotted as a function of current and previous trial congruency, for theta (red) and alpha (blue) stimulation conditions. Right: similar to left plot, but now the tACS effect was defined as [post–pre]. e) Cross-subject correlation between alpha peak frequency used for stimulation, and the tACS-induced change ([stim–pre]–[post–pre]) in the CSE ([cI–cC]–[iI–iC]). *** p < 0.001.