Frequency and state specific hemispheric asymmetries in the human sleep EEG

Neurosci Lett. 1999 Aug 27;271(3):139-42. doi: 10.1016/s0304-3940(99)00048-8.


Regional differences in the sleep EEG along the antero-posterior axis have been recently described. To test for state related, hemispheric differences, sleep records from homologous fronto-central, centro-parietal and parieto-occipital derivations were obtained from 14 young right-handed males. Within the frequency range of sleep spindles (11-15 Hz) power in non-REM sleep dominated in the left hemisphere in all derivations. In the centro-parietal 4-8 Hz band a right-hemispheric predominance prevailed in non-REM sleep and a left-hemispheric predominance in REM sleep. Since the frequency bands exhibiting hemispheric asymmetries are those in which large antero-posterior power gradients had been observed, the left-right differences may arise from structural and functional asymmetries of brain regions involved in the generation of the sleep EEG.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cerebral Cortex / physiology*
  • Dominance, Cerebral / physiology*
  • Electroencephalography*
  • Frontal Lobe / physiology
  • Humans
  • Male
  • Occipital Lobe / physiology
  • Parietal Lobe / physiology
  • Sleep, REM / physiology*