Figure 3

Two out of three insomnia subtypes have delta-power deficiencies during NREM sleep. Global EEG spectral power (A) across delta, theta, alpha, sigma and beta frequency bands during NREM sleep and in the right (B) and left hemispheres (C). Error bars indicate standard error of the mean, SSDD short-sleep delta-deficient subtype, NSDD normal-sleep delta-deficient, NNS normal neurophysiological sleep subtype, *p < 0.05 denotes the significant difference compared to controls.