When analysing the two stimulation conditions separately, the effect of TIME was highly significant in the theta-tACS condition ( F (1,52) = 33.78, p < 0.001, η 2 = 0.014, BF incl = 13,348.545 ) and in the control stimulation ( F (1,52) = 8.92, p = 0.004, η 2 = 0.005; BF incl = 7.993 ), which again applied to both groups.
delayed recall) revealed a marginal trend in the opposite direction as predicted ( F (1,51) = 3.86, p = 0.055, η 2 < 0.001, BF incl = 0.287 ).
Therefore, we did not reach the calculated numbers of participants of 36 in each group ( encoding group : 30; retrieval group: 23), which might explain that some results were only close to significance or that we found no strong effects.