dsz > 0.797), replicating the between-group differences of Experiment 1. Second, frontotemporal theta-tuned stimulation relative to sham preferentially enhanced the accuracy of working memory behavior in older adults independent of RT, and these post-stimulation accuracy gains were large enough to eliminate age-related differences in behavior between groups (t68 = 0.956, p = 0.343, dz = 0.229), consistent with results from Experiment 1. Moreover, like Experiment 1, the stimulation-induced accuracy improvements remained significantly elevated relative to sham levels for the entire experiment beginning with time bin 2 (ts27 > 2.886, ps < 0.008, dsz > 0.545), whereas RT speeding lagged behind accuracy gains and were short-lived, only observed at time bins 3–5 (ts27 > 2.537, ps < 0.017, dsz > 0.479). Third, although the frontotemporal 8-Hz nontuned stimulation appeared to have a slight beneficial influence, qualitatively, on performance accuracy in post-stimulation blocks, neither accuracy, nor RT significantly differed compared to sham. Similarly, no differences between sham and 8-Hz conditions at any of the nine sequential 4-minute-long time bins over the course of the experiment reached significance (ts27 < 1.801, ps > 0.083, dsz < 0.340). Fourth, relative to sham, the frontal-alone and temporal-alone theta-tuned montages had no significant impact on performance
