ImCoh changes across sessions for the tACS and sham groups. The boxplots show the median and interquartile range to visually summarize central tendency and dispersion. The horizontal line within the box plot represents the median. The top and the bottom lines represent the upper and lower quartiles, respectively. The data points outside of the whiskers are >1.5 quartiles. Asterisk (*) denotes a statistically significant change within the group. The tACS group showed a statistically significant increase in ImCoh from session 1 to session 5, and the increase was maintained at the 7-d FU. ^***P < 0.001.