title: Complex relationship between BOLD signal and synchronization/desynchronization of human brain MEG oscillations.
abstract: Functional magnetic resonance imaging (fMRI) depends on the coupling of cerebral blood flow, energy demand, and neural activity. The precise nature of this interaction, however, is poorly understood. A positive correlation between BOLD-response and cortically generated local field potentials, which reflect the weighted average of synchronized dentrosomatic components of pyramidal synaptic signals, has been demonstrated. Likewise, positive BOLD-responses have been reported in conjunction with scalp-recorded synchronized electromagnetic activity by a number of groups. However, it is not yet clear how the opposite electromagnetic pattern, i.e. cortical desynchronization, is related to the BOLD signal. To address this question, we conducted a combined event-related fMRI and 275 sensor whole-head MEG study during identical visual two-choice reaction time task conditions in 10 human subjects. We found complex sequences of MEG-synchronization and desynchronization across a wide frequency range in the visual and motor area in close correspondence with "locales" of positive BOLD-responses. These results indicate that a correspondence of positive BOLD-responses is not exclusively found for cortical synchronization but also for desynchronization, suggesting that the relationship between BOLD signals and electromagnetic activity might be more complex than previously thought.
authors.affiliation: MEG Core Facility, National Institute of Mental Health, National Institutes of Health, Bethesda, USA. georg.winterer@uni-duesseldorf.de
authors.forename: Georg
authors.initials: G
authors.lastname: Winterer
authors.forename: Frederick W
authors.initials: FW
authors.lastname: Carver
authors.forename: Francesco
authors.initials: F
authors.lastname: Musso
authors.forename: Venkata
authors.initials: V
authors.lastname: Mattay
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Weinberger
authors.forename: Richard
authors.initials: R
authors.lastname: Coppola
mesh_terms: D000328:Adult; D001611:Beta Rhythm; D003344:Cortical Synchronization; D003627:Data Interpretation, Statistical; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D010100:Oxygen / Q000097:blood*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013826:Theta Rhythm; D014796:Visual Perception / Q000502:physiology
chemical_list: D010100:Oxygen