Fig. 1B: correlation between CFC strength and impedance  Assumed normal distribution of the errors  Pearson correlation tested using t test  n = 80 electrodes of 1 animal over 5 sessions  ρ = –0.255 p = 0.0224 
Fig. 1C: impedance values for two different sizes of electrodes  Assumed normal distribution  Independent t test; tbased confidence intervals for the mean  n = 20 single wires and 60 tetrode wires electrodes of 1 animal over 5 sessions  CI_{95} = [1072;1672] Cohen’s d = 2.7 p = 7.0773 × 10^{−14}

Fig. 1C: CFC strength for two different sizes of electrodes  Assumed normal distribution  Independent t test; tbased confidence intervals for the mean  n = 20 single wires and 60 tetrode wires electrodes of 1 animal over 5 sessions  CI_{95} = [0.9; 5.8] × 10^{−3}
Cohen’s d = 0.6 p = 0.007 
Fig. 3A: comodulograms were compared to a surrogate distribution obtained by randomly splitting and inverting the amplitude time series  Assumed nonnormal distribution  Surrogate test  200 surrogates for each channel  Each x–y entry was set to zero (dark blue color) if observed p > 0; otherwise, the original value was kept. 
Fig. 5C: LG power comparison for aWK and REM sleep  Assumed normal distribution  Dependent t test; tbased confidence intervals for the mean  n = 7 animals (mean across electrodes)  CI_{95} = [–1.3; 2.73]; Cohen’s d = 0.33; p = 0.42 
Fig. 5C: HG power comparison for aWK and REM sleep  Assumed normal distribution  Dependent t test; tbased confidence intervals for the mean  n = 7 animals (mean across electrodes)  CI_{95} = [–0.39; 1.1]; Cohen’s d = 0.44; p = 0.29 
Fig. 5C: HFO power comparison for aWK and REM sleep.  Assumed normal distribution  Dependent t test; tbased confidence intervals for the mean  n = 7 animals (mean across electrodes)  CI_{95} = [0.15; 0.58]; Cohen’s d = 1.57; p = 0.006 
Fig. 5C: Theta–LG coupling strength comparison for aWK and REM sleep  Assumed normal distribution  Dependent t test; tbased confidence intervals for the mean  n = 7 animals (mean across electrodes)  CI_{95} = [–0.22; 0.11] × 10^{−3}; Cohen’s d = 0.31; p = 0.45 
Fig. 5C: Theta–HG coupling strength comparison for aWK and REM sleep  Assumed normal distribution  Dependent t test; tbased confidence intervals for the mean  n = 7 animals (mean across electrodes)  CI_{95} = [0.03; 2.14] × 10^{−3}; Cohen’s d = 0.95 p = 0.045 
Fig. 5C: Theta–HFO coupling strength comparison for aWK and REM sleep  Assumed normal distribution  Dependent t test; tbased confidence intervals for the mean  n = 7 animals (mean across electrodes)  CI_{95} = [3; 10.8] × 10^{−3}; Cohen’s d = 1.64; p = 0.005 
Fig. 5D: Theta power comparison for aWK and REM sleep  Assumed normal distribution  Dependent t test; tbased confidence intervals for the mean  n = 7 animals (mean across electrodes)  CI_{95} = [0.11; 0.2]; Cohen’s d = 3.19; p = 1.52 × 10^{−4}
