title: Independent component analysis for source localization of EEG sleep spindle components.
abstract: Sleep spindles are bursts of sleep electroencephalogram (EEG) quasirhythmic activity within the frequency band of 11-16 Hz, characterized by progressively increasing, then gradually decreasing amplitude. The purpose of the present study was to process sleep spindles with Independent Component Analysis (ICA) in order to investigate the possibility of extracting, through visual analysis of the spindle EEG and visual selection of Independent Components (ICs), spindle "components" (SCs) corresponding to separate EEG activity patterns during a spindle, and to investigate the intracranial current sources underlying these SCs. Current source analysis using Low-Resolution Brain Electromagnetic Tomography (LORETA) was applied to the original and the ICA-reconstructed EEGs. Results indicated that SCs can be extracted by reconstructing the EEG through back-projection of separate groups of ICs, based on a temporal and spectral analysis of ICs. The intracranial current sources related to the SCs were found to be spatially stable during the time evolution of the sleep spindles.
authors.affiliation: Department of Medical Instrumentation Technology, Technological Educational Institution of Athens, Ag Spyridonos Street, Egaleo, 12210 Athens, Greece.
authors.forename: Erricos M
authors.initials: EM
authors.lastname: Ventouras
authors.forename: Periklis Y
authors.initials: PY
authors.lastname: Ktonas
authors.forename: Hara
authors.initials: H
authors.lastname: Tsekou
authors.forename: Thomas
authors.initials: T
authors.lastname: Paparrigopoulos
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kalatzis
authors.forename: Constantin R
authors.initials: CR
authors.lastname: Soldatos
mesh_terms: D000328:Adult; D000465:Algorithms; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D006801:Humans; D008297:Male; D012815:Signal Processing, Computer-Assisted; D012890:Sleep / Q000502:physiology*; D013997:Time Factors