title: The default mode network and EEG regional spectral power: a simultaneous fMRI-EEG study.
abstract: Electroencephalography (EEG) frequencies have been linked to specific functions as an "electrophysiological signature" of a function. A combination of oscillatory rhythms has also been described for specific functions, with or without predominance of one specific frequency-band. In a simultaneous fMRI-EEG study at 3 T we studied the relationship between the default mode network (DMN) and the power of EEG frequency bands. As a methodological approach, we applied Multivariate Exploratory Linear Optimized Decomposition into Independent Components (MELODIC) and dual regression analysis for fMRI resting state data. EEG power for the alpha, beta, delta and theta-bands were extracted from the structures forming the DMN in a region-of-interest approach by applying Low Resolution Electromagnetic Tomography (LORETA). A strong link between the spontaneous BOLD response of the left parahippocampal gyrus and the delta-band extracted from the anterior cingulate cortex was found. A positive correlation between the beta-1 frequency power extracted from the posterior cingulate cortex (PCC) and the spontaneous BOLD response of the right supplementary motor cortex was also established. The beta-2 frequency power extracted from the PCC and the precuneus showed a positive correlation with the BOLD response of the right frontal cortex. Our results support the notion of beta-band activity governing the "status quo" in cognitive and motor setup. The highly significant correlation found between the delta power within the DMN and the parahippocampal gyrus is in line with the association of delta frequencies with memory processes. We assumed "ongoing activity" during "resting state" in bringing events from the past to the mind, in which the parahippocampal gyrus is a relevant structure. Our data demonstrate that spontaneous BOLD fluctuations within the DMN are associated with different EEG-bands and strengthen the conclusion that this network is characterized by a specific electrophysiological signature created by combination of different brain rhythms subserving different putative functions.
authors: Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Jülich, Germany ; Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany ; JARA - BRAIN - Translational Medicine, RWTH Aachen University, Aachen, Germany.
authors: Irene
authors: I
authors: Neuner
authors: Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Jülich, Germany.
authors: Jorge
authors: J
authors: Arrubla
authors: Department of Neurology, RWTH Aachen University, Aachen, Germany.
authors: Cornelius J
authors: CJ
authors: Werner
authors: Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, Zurich, Switzerland.
authors: Konrad
authors: K
authors: Hitz
authors: Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Jülich, Germany.
authors: Frank
authors: F
authors: Boers
authors: Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, Zurich, Switzerland.
authors: Wolfram
authors: W
authors: Kawohl
authors: Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Jülich, Germany ; JARA - BRAIN - Translational Medicine, RWTH Aachen University, Aachen, Germany ; Department of Neurology, RWTH Aachen University, Aachen, Germany.
authors: N Jon
authors: NJ
authors: Shah
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D058256:Brain Waves; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055815:Young Adult