title: Detection of EEG-resting state independent networks by eLORETA-ICA method.
abstract: Recent functional magnetic resonance imaging (fMRI) studies have shown that functional networks can be extracted even from resting state data, the so called "Resting State independent Networks" (RS-independent-Ns) by applying independent component analysis (ICA). However, compared to fMRI, electroencephalography (EEG) and magnetoencephalography (MEG) have much higher temporal resolution and provide a direct estimation of cortical activity. To date, MEG studies have applied ICA for separate frequency bands only, disregarding cross-frequency couplings. In this study, we aimed to detect EEG-RS-independent-Ns and their interactions in all frequency bands. We applied exact low resolution brain electromagnetic tomography-ICA (eLORETA-ICA) to resting-state EEG data in 80 healthy subjects using five frequency bands (delta, theta, alpha, beta and gamma band) and found five RS-independent-Ns in alpha, beta and gamma frequency bands. Next, taking into account previous neuroimaging findings, five RS-independent-Ns were identified: (1) the visual network in alpha frequency band, (2) dual-process of visual perception network, characterized by a negative correlation between the right ventral visual pathway (VVP) in alpha and beta frequency bands and left posterior dorsal visual pathway (DVP) in alpha frequency band, (3) self-referential processing network, characterized by a negative correlation between the medial prefrontal cortex (mPFC) in beta frequency band and right temporoparietal junction (TPJ) in alpha frequency band, (4) dual-process of memory perception network, functionally related to a negative correlation between the left VVP and the precuneus in alpha frequency band; and (5) sensorimotor network in beta and gamma frequency bands. We selected eLORETA-ICA which has many advantages over the other network visualization methods and overall findings indicate that eLORETA-ICA with EEG data can identify five RS-independent-Ns in their intrinsic frequency bands, and correct correlations within RS-independent-Ns.
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine Osaka, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Aoki
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine Osaka, Japan.
authors.forename: Ryouhei
authors.initials: R
authors.lastname: Ishii
authors.affiliation: The KEY Institute for Brain-Mind Research, University Hospital of Psychiatry Zurich, Switzerland ; Department of Neuropsychiatry, Kansai Medical University Osaka, Japan.
authors.forename: Roberto D
authors.initials: RD
authors.lastname: Pascual-Marqui
authors.affiliation: UCM-UPM Centre for Biomedical Technology, Department of Cognitive and Computational Neuroscience, Complutense University of Madrid Madrid, Spain.
authors.forename: Leonides
authors.initials: L
authors.lastname: Canuet
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine Osaka, Japan.
authors.forename: Shunichiro
authors.initials: S
authors.lastname: Ikeda
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine Osaka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hata
authors.affiliation: Nihon Kohden Shinjuku, Tokyo, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Imajo
authors.affiliation: Brain Functions Laboratory Incorporated Yokohama, Japan.
authors.forename: Haruyasu
authors.initials: H
authors.lastname: Matsuzaki
authors.affiliation: Brain Functions Laboratory Incorporated Yokohama, Japan.
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Musha
authors.affiliation: Department of Neuropsychiatry, Institute of Clinical Medicine, University of Tsukuba Tsukuba, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Asada
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine Osaka, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Iwase
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine Osaka, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Takeda
keywords: EEG; ICA; LORETA; eLORETA-ICA; independent component analysis; resting state network