Panel A: Bivariate correlations between spectral parameters (intercept, slope, variance accounted for, and the frequency, power and bandwidth of NREM sigma, REM theta and REM beta peaks) and cognitive performance, residualized for four covariate sets. Dual horizontal lines illustrate the critical significance level assuming zero missingness. Asterisks mark correlations which remain significant after controlling for multiple comparisons. Panel B: Point-biserial correlations between the missingness of spectral peaks (NREM sigma, REM theta and REM beta peaks) and cognitive performance, residualized for four covariate sets. Dual horizontal lines illustrate the critical significance level assuming zero missingness. Asterisks mark correlations which remain significant after controlling for multiple comparisons.