THE K-COMPLEX - ITS SLOW (LESS-THAN-1-HZ) RHYTHMICITY AND RELATION TODELTA-WAVES

The K-complex is a major graphoelement of sleep EEG. This report demon strates that K-complexes emerge from a cortically generated slow (<1-H z) oscillation. Human EEG as well as cat cellular and field potential recordings converge into demonstrating that the K-complex results from a synchronized cortical network that imposes periodic excitatory and inhibitory actions on cortical neurons. We additionally show the corre spondence between neuronal activities and the shape of the K-complex. Spectral analysis confirms the periodic recurrence of human K-complexe s, with main peaks at 0.5 to 0.7 Hz. It is also shown that the spectra l content in the delta band (1 to 4 Hz) is partially due to the shape and duration of the K-complex.