[Color-coded sleep EEG power density spectra]

The colour-coded representation of transformed sleep EEG power density spectra makes it possible to demonstrate changes in sleep architecture. With the aid of this method, spectral changes in physical units can be shown. The present study also shows that sleep is a continuous process which, for clinical interpretation, urgently needs to be processed with this in mind, in particular for the investigation of the effects of psychopharmaceuticals. The method is derived mathematically, and illustrated by convincing examples. It is to be hoped that the method will be accepted without delay and its use spread rapidly.