EEG coherence functions for normal newborns in relation to their sleep state

While power spectra provide little information about the properties of the newborn EEG, the coherence functions (especially interhemispheric) have a characteristic shape for each of the 2 sleep states. Coherence functions may therefore be clinically more important than spectra. For this reason, baseline data for normal newborns have been produced as a reference against which coherences from patients can be compared. It is stressed that for a sleeping newborn the behavioural state must be known for the coherence function to be interpretable. Furthermore, since intraindividual variability is large, data from long recordings are required. The results are discussed in the light of the existing literature.