Fig. 5: EEG-based reactivation during PRE and POST Rest.

a In EEG-based task reactivations, there was a significant higher reactivation strength during POST than PRE Rest (two-sided paired t-test: t₍₃₁₎ = 2.75, P = 0.010). n = 32, excluding an outlier (beyond three deviation of the mean). b Parametric modulation of EEG-based reactivation probability in whole-brain fMRI during POST Rest showed significant activations in bilateral anterior hippocampus (whole-brain FWE correction at the cluster level (P < 0.05) with a cluster-forming voxel threshold of P_unc. < 0.001). c ROI analysis. The EEG-based reactivation explained hippocampal activation (anatomically defined) during POST Rest, and it was stronger from PRE to POST Rest in hippocampus (two-sided one-sample t-test: PRE: t₍₃₂₎ = 1.08, P_corr. = 0.287; POST: t₍₃₂₎ = 3.83, P_corr. < 0.001; two-sided paired t-test: POST vs. PRE: t₍₃₂₎ = 2.44, P_corr. = 0.030; FDR corrected). n = 33_. d, The task reactivation-aligned BOLD signal in hippocampus during POST Rest. Upon alignment to the onsets of task-related reactivation, we observed a significant increase in hippocampal BOLD activity, peaking at the 2^nd TR post-EEG-based reactivation (two-sided one-sample t-test: TR = 1: t₍₃₂₎ = 2.57, P = 0.015; TR = 2: t₍₃₂₎ = 3.02, P = 0.005), and also found at onset of fMRI-based reactivation (TR = 0: two-sided one-sample t-test: t₍₃₂₎ = 2.45, P = 0.020). n = 33. e The PPI between hippocampal activity (anatomically defined) and EEG-based reactivation probability showed increased functional connectivity with EC (anatomical mask depicted in blue) during POST Rest. We thresholded at P_unc. < 0.01, K > 10 for visualization. f ROI analysis. The PPI revealed a significant increase in hippocampal-seed connectivity with the EC (anatomically defined) during POST Rest when EEG-based reactivation increased. (two-sided one-sample t-test: PRE: t₍₃₂₎ = 1.48, P = 0.148; POST: t₍₃₂₎ = 2.75, P = 0.010). n = 33. g There was a positive correlation between EEG-based and fMRI-based reactivation in explaining hippocampal activity during POST Rest, but not PRE Rest (robust correlation, PRE: r = 0.09, P = 0.602; POST: r = 0.38, P = 0.029). n = 33. The solid lines reflect the robust linear fit. Each dot is one subject. The grey lines connect results from the same subject. Shaded areas in d show SEM across subjects. Error bars in a, c and f show SEM across subjects. * P < 0.05, ** P < 0.01, *** P < 0.001, ns., not significant. Abbreviation: HPC - hippocampus. Source data are provided as a Source Data file.