title: Regions, systems, and the brain: hierarchical measures of functional integration in fMRI.
abstract: In neuroscience, the notion has emerged that the brain abides by two principles: segregation and integration. Segregation into functionally specialized systems and integration of information flow across systems are basic principles that are thought to shape the functional architecture of the brain. A measure called integration, originating from information theory and derived from mutual information, has been proposed to characterize the global integrative state of a network. In this paper, we show that integration can be applied in a hierarchical fashion to quantify functional interactions between compound systems, each system being composed of several regions. We apply this method to fMRI datasets from patients with low-grade glioma and show how it can efficiently extract information related to both intra- and interhemispheric reorganization induced by lesional brain plasticity.
authors.affiliation: Inserm, U678, Paris F-75013, France; Université Pierre et Marie Curie, Faculté de Médecine Pitié-Salpêtrière, Paris F-75013, France; Université de Montréal, MIC/UNF, Montreal, Canada H3W 1W5.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Marrelec
authors.affiliation: Inserm, U678, Paris F-75013, France; Université Pierre et Marie Curie, Faculté de Médecine Pitié-Salpêtrière, Paris F-75013, France; McGill University, MNI, BIC, Montreal, Canada H3A 2B4.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bellec
authors.affiliation: Inserm, U594, Grenoble F-38000, France; CHU La Tronche, Department of Neuroradiology, Grenoble F-38000, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Krainik
authors.affiliation: Inserm, U678, Paris F-75013, France; Université Pierre et Marie Curie, Faculté de Médecine Pitié-Salpêtrière, Paris F-75013, France; CHU de Montpellier, Hôpital Gui de Chaulic, Montpellier F-34295, France.
authors.forename: Hugues
authors.initials: H
authors.lastname: Duffau
authors.affiliation: Inserm, U678, Paris F-75013, France; Université Pierre et Marie Curie, Faculté de Médecine Pitié-Salpêtrière, Paris F-75013, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Pélégrini-Issac
authors.affiliation: AP-HP, Hôpital Pitié-Salpêtrière, Department of Neuroradiology, Paris F-75013, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lehéricy
authors.affiliation: Inserm, U678, Paris F-75013, France; Université Pierre et Marie Curie, Faculté de Médecine Pitié-Salpêtrière, Paris F-75013, France; Université de Montréal, MIC/UNF, Montreal, Canada H3W 1W5.
authors.forename: Habib
authors.initials: H
authors.lastname: Benali
authors.affiliation: Inserm, U678, Paris F-75013, France; Université Pierre et Marie Curie, Faculté de Médecine Pitié-Salpêtrière, Paris F-75013, France; Université de Montréal, MIC/UNF, Montreal, Canada H3W 1W5.
authors.forename: Julien
authors.initials: J
authors.lastname: Doyon
mesh_terms: D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001932:Brain Neoplasms / Q000503:physiopathology; D005910:Glioma / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009473:Neuronal Plasticity / Q000502:physiology