To investigate any relationship between these induced theta group effects and prestimulus levels of theta power during the task, first, a univariate ANOVA was performed with group as the between-subjects factor and the dependent measure mean prestimulus theta power (log-transformed power averaged within the prestimulus TFROI). There was a main effect of group (F(2, 143) = 14.96, P < 0.001, ηp2 = 0.17). Post hoc Tukey's HSD tests showed that while NAC (mean = 0.69 ± SE = 0.03) and LTAA (0.66 ± 0.03) did not differ from each other (P = 0.78, d = 0.13), STAA (0.45 ± 0.04) had lower task prestimulus theta power than both NAC and LTAA (both P < 0.001, d = 1.15 and 1.02, respectively). Next, an ANCOVA on induced theta with task prestimulus power as the covariate showed a main effect of group (F(2, 142) = 4.94, P = 0.008, ηp2 = 0.07). Follow-up pairwise comparisons on the groups' adjusted means revealed, however, that while induced theta ERS in both STAA and LTAA were still larger than NAC (both P ≤ 0.01; d
