Experiment 1, phase synchronization results.a, A significant cluster in prefrontal cortex showed increased phase-locked value (PLV) with temporal cortex seed region in the theta band for younger adults at baseline and for older adults after stimulation (pcorrected < 0.01, two-sided cluster permutation test, n = 42). For theta PLV, the between-group difference at baseline (t82 = 6.450, p < 0.01, dz = 0.995) and the between-condition difference within older adults (t41 = 8.238, p < 0.01, dz = 1.271) were significant. b, A significant cluster in lateral occipital cortex showed increased PLV with temporal cortex seed region in the gamma band for each group and condition (pcorrected < 0.01, two-sided cluster permutation test, n = 42). For gamma PLV, there were no significant group (t82 = 0.898, p = 0.374, dz = 0.139) or condition differences (t41 = 1.012, p = 0.317, dz = 0.156). No other clusters were found. Between-group comparisons used independent two-tailed t-tests (n = 84). Within-group comparisons used paired sample two-tailed t-tests (n = 42). Box-plot center, median; box limits, lower and upper quartiles; whiskers, lower and upper extreme values; points, outliers.
