Fig. 8

Phase-dependent tACS-mediated topographical maps of prestimulus theta and alpha power in the incongruent condition. (A) The topographical maps show the grand-averaged prestimulus theta (500 to 200 ms prestimulus) and alpha (400 to 100 ms prestimulus) power distributions given in the order of in-phase (left) and out-of-phase (right) stimulation. The view of the topography is from the vertex perspective with the nose at the top of the image. (B) The time-frequency plots represent the spectral power of total activity at the electrode Fz. Time 0 indicates stimulus onset. The color bar indicates the power (µV²). (C) Comparison of prestimulus spectral power (µV²; in the frontocentral region averaged across Fz, F1, F2, and FCz, from 400 to 200 ms prestimulus) between in-phase (red bars) and out-of-phase (blue bars) tACS treatments across the delta (1–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), beta (13–30 Hz), and gamma (30–50 Hz) bands. The error bars indicate the standard errors of the mean, and the asterisks represent statistical significance (*p < 0.05). Note the phase-dependent tACS-mediated significant differences particularly in theta and alpha bands