title: Dynamic reorganization of functional brain networks during picture naming.
abstract: For efficient information processing during cognitive activity, functional brain networks have to rapidly and dynamically reorganize on a sub-second time scale. Tracking the spatiotemporal dynamics of large scale networks over this short time duration is a very challenging issue. Here, we tackle this problem by using dense electroencephalography (EEG) recorded during a picture naming task. We found that (i) the picture naming task can be divided into six brain network states (BNSs) characterized by significantly high synchronization of gamma (30-45 Hz) oscillations, (ii) fast transitions occur between these BNSs that last from 30 msec to 160 msec, (iii) based on the state of the art of the picture naming task, we consider that the spatial location of their nodes and edges, as well as the timing of transitions, indicate that each network can be associated with one or several specific function (from visual processing to articulation) and (iv) the comparison with previously-used approach aimed at localizing the sources showed that the network-based approach reveals networks that are more specific to the performed task. We speculate that the persistence of several brain regions in successive BNSs participates to fast and efficient information processing in the brain.
authors.affiliation: INSERM, U1099, Rennes, France; Université de Rennes 1, LTSI, France. Electronic address: mahmoud.hassan@univ-rennes1.fr.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Hassan
authors.affiliation: INSERM, U1099, Rennes, France; Université de Rennes 1, LTSI, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Benquet
authors.affiliation: INSERM, U1099, Rennes, France; Université de Rennes 1, LTSI, France; Neurology Department, CHU, Rennes, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Biraben
authors.affiliation: Télécom Bretagne (Institut Mines-Télécom), UMR CNRS Lab-STICC, Brest, France; UMR CNRS Lab-STICC, Brest, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Berrou
authors.affiliation: Télécom Bretagne (Institut Mines-Télécom), UMR CNRS Lab-STICC, Brest, France; UMR CNRS Lab-STICC, Brest, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Dufor
authors.affiliation: INSERM, U1099, Rennes, France; Université de Rennes 1, LTSI, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Wendling
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D009424:Nervous System Physiological Phenomena; D009434:Neural Pathways / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D055815:Young Adult
keywords: Brain dynamics; Dense EEG; Evoked potentials; Picture naming