This functional three-structuring of the endogenous-autonomic system also shows itself in a different behavior of performance of the individual rhythmic processes
(illustration 7).
Thus, the performance of the information system is expressed in the gliding frequency changes of the nerval action rhythm, whereby each frequency is in close correlation to level of excitement of the nervous elements, and therefore also to the intensity of the specific environmental effects which hit them. With acoustic stimuli, the pitch is also illustrated in the nerval rhythm. Only under peaceful conditions and especially during sleep, are the nervous elements, dependent on the depth of sleep, synchronized to tissue rhythms with favored frequency bands (cf. the EEG-criteria for depth of sleep).