title: Simultaneous spatio-temporal matching pursuit decomposition of evoked brain responses in MEG.
abstract: We present a novel approach to the spatio-temporal decomposition of evoked brain responses in magnetoencephalography (MEG) aiming at a sparse representation of the underlying brain activity in terms of spatio-temporal atoms. Our approach is characterized by three attributes which constitute significant improvements with respect to existing approaches: (1) the spatial and temporal decomposition is addressed simultaneously rather than sequentially, with the benefit that source loci and corresponding waveforms can be unequivocally allocated to each other, and, hence, allow a plausible physiological interpretation of the parametrized data; (2) it is free from severe a priori assumptions about the solution space; (3) it comprises an optimization technique for the use of very large spatial and temporal subdirectories to greatly reduce the otherwise enormous computational cost by making use of the Cauchy-Schwarz inequality. We demonstrate the efficiency of the approach with simulations and real MEG data obtained from a subject exposed to a simple auditory stimulus.
authors.affiliation: Biomedical Physics Division, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland.|Special Lab Non-Invasive Brain Imaging, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany.
authors.forename: Paweł
authors.initials: P
authors.lastname: Kordowski
authors.affiliation: Special Lab Non-Invasive Brain Imaging, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany.
authors.forename: Artur
authors.initials: A
authors.lastname: Matysiak
authors.affiliation: Special Lab Non-Invasive Brain Imaging, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: König
authors.affiliation: Special Lab Non-Invasive Brain Imaging, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany.|Control of Normal and Abnormal Movements Team, ICM Brain and Spine Institute, Pierre-and-Marie-Curie University (Paris VI, Sorbonne), INSERM UMR1127, CNRS UMR7225, Hôpital Pitié Salpêtrière, 47 bd de l'Hôpital, 75013, Paris, France.|Faculty of Computer Science and Management, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.|Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland. cezary.sieluzycki@pwr.edu.pl.
authors.forename: Cezary
authors.initials: C
authors.lastname: Sielużycki
mesh_terms: D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging; D006801:Humans; D015225:Magnetoencephalography; D062211:Spatio-Temporal Analysis
keywords: Evoked responses; M100; Magnetoencephalography (MEG); Matching pursuit; Spatio-temporal decomposition