Correlates of alpha rhythm in functional magnetic resonance imaging and near infrared spectroscopy

Neuroimage. 2003 Sep;20(1):145-58. doi: 10.1016/s1053-8119(03)00344-6.


We used simultaneous electroencephalogram-functional magnetic resonance imaging (EEG-fMRI) and EEG-near infrared spectroscopy (NIRS) to investigate whether changes of the posterior EEG alpha rhythm are correlated with changes in local cerebral blood oxygenation. Cross-correlation analysis of slowly fluctuating, spontaneous rhythms in the EEG and the fMRI signal revealed an inverse relationship between alpha activity and the fMRI-blood oxygen level dependent signal in the occipital cortex. The NIRS-EEG measurements demonstrated a positive cross-correlation in occipital cortex between alpha activity and concentration changes of deoxygenated hemoglobin, which peaked at a relative shift of about 8 s. Our data suggest that alpha activity in the occipital cortex is associated with metabolic deactivation. Mapping of spontaneously synchronizing distributed neuronal networks is thus shown to be feasible.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alpha Rhythm*
  • Brain Chemistry / physiology*
  • Electroencephalography
  • Energy Metabolism / physiology
  • Female
  • Hemoglobins / metabolism
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Oxygen / blood*
  • Photic Stimulation
  • Spectroscopy, Near-Infrared*


  • Hemoglobins
  • deoxyhemoglobin
  • Oxygen