Brain Topography

, Volume 15, Issue 1, pp 43–49 | Cite as

Scalp Topography of the Spontaneous K-Complex and of Delta-Waves in Human Sleep

  • Svenja Happe
  • Peter Anderer
  • Georg Gruber
  • Gerhard Klösch
  • Bernd Saletu
  • Josef Zeitlhofer


Objective: Together with spindles, K-complexes are well known hallmarks of stage 2 sleep (S2). However, little is known about their topographical distribution in comparison to delta-waves and to K-complexes superimposed by spindles. Patients and methods: In this study, the topographical distribution of spontaneous K-complexes and delta-waves in S2 and delta-waves in stage 4 sleep (S4) in 10 healthy young adults (aged 20 to 35 years, 7 female) was investigated. K-complexes with and without spindles in S2, delta-waves with and without spindles in S2, and delta-waves in S4 distributed all over the night were visually selected. EEG power maps and statistical parametric maps were calculated. Results: Absolute delta power of S2 K-complexes appeared to be significantly higher than of S2 delta-waves and delta power of S4 delta-waves was higher than of S2 delta-waves. In K-complexes and delta-waves, power was found to be highest over medio-frontal regions in the delta frequency band (0.5 - 4.0 Hz) with a second maximum occipitally in delta-waves, no matter whether superimposed by a spindle or not. Conclusion: K-complexes and delta-waves in S2 differ in topographical distribution. Even though in S2 delta-waves have less power, they have a similar topographical distribution in S2 and S4, supporting the hypothesis that delta-waves in S2 further develop towards delta-waves in slow wave sleep. The delta frequency components of K-complexes and delta-waves are unaffected by spindles.

K-complex Delta-wave Sleep spindle Stage 2 sleep Stage 4 sleep Topography 


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Copyright information

© Human Sciences Press, Inc. 2002

Authors and Affiliations

  • Svenja Happe
    • 1
    • 2
  • Peter Anderer
    • 3
  • Georg Gruber
    • 3
  • Gerhard Klösch
    • 4
  • Bernd Saletu
    • 3
  • Josef Zeitlhofer
    • 4
  1. 1.Department of Neurology,University of Vienna,Austria
  2. 2.Department of Clinical Neurophysiology,University of Goettingen,Germany
  3. 3.Department of Psychiatry,University of Vienna,Austria
  4. 4.Department of Neurology,University of Vienna,Austria

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