The analytical noise ceiling estimator (blue) and its true value (red) are presented for different levels of variance of the noise (the variance of the signal is equal to one).

The left panel shows the noise ceiling for the correlation coefficient while the right panel shows the noise ceiling for the explained variance. The grey shadowed area denotes the [5 95] percentiles of the true NC distribution, while the blue dashed line denotes the [5 95] percentiles for the estimated NC across 100 simulations.