title: Correlates of alpha rhythm in functional magnetic resonance imaging and near infrared spectroscopy.
abstract: 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.
authors.affiliation: Department of Neurology, Charité, Humboldt University, Berlin, Germany. moosmann@charite.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Moosmann
authors.forename: Petra
authors.initials: P
authors.lastname: Ritter
authors.forename: Ina
authors.initials: I
authors.lastname: Krastel
authors.forename: Andrea
authors.initials: A
authors.lastname: Brink
authors.forename: Sebastian
authors.initials: S
authors.lastname: Thees
authors.forename: Felix
authors.initials: F
authors.lastname: Blankenburg
authors.forename: Birol
authors.initials: B
authors.lastname: Taskin
authors.forename: Hellmuth
authors.initials: H
authors.lastname: Obrig
authors.forename: Arno
authors.initials: A
authors.lastname: Villringer
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001923:Brain Chemistry / Q000502:physiology*; D004569:Electroencephalography; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood*; D010775:Photic Stimulation; D019265:Spectroscopy, Near-Infrared
chemical_list: D006454:Hemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen