title: Hierarchical functional modularity in the resting-state human brain.
abstract: Functional magnetic resonance imaging (fMRI) studies have shown that anatomically distinct brain regions are functionally connected during the resting state. Basic topological properties in the brain functional connectivity (BFC) map have highlighted the BFC's small-world topology. Modularity, a more advanced topological property, has been hypothesized to be evolutionary advantageous, contributing to adaptive aspects of anatomical and functional brain connectivity. However, current definitions of modularity for complex networks focus on nonoverlapping clusters, and are seriously limited by disregarding inclusive relationships. Therefore, BFC's modularity has been mainly qualitatively investigated. Here, we introduce a new definition of modularity, based on a recently improved clustering measurement, which overcomes limitations of previous definitions, and apply it to the study of BFC in resting state fMRI of 53 healthy subjects. Results show hierarchical functional modularity in the brain.
authors.affiliation: Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands. l.ferrarini@lumc.nl
authors.forename: Luca
authors.initials: L
authors.lastname: Ferrarini
authors.forename: Ilya M
authors.initials: IM
authors.lastname: Veer
authors.forename: Evelinda
authors.initials: E
authors.lastname: Baerends
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: van Tol
authors.forename: Remco J
authors.initials: RJ
authors.lastname: Renken
authors.forename: Nic J A
authors.initials: NJ
authors.lastname: van der Wee
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Veltman
authors.forename: André
authors.initials: A
authors.lastname: Aleman
authors.forename: Frans G
authors.initials: FG
authors.lastname: Zitman
authors.forename: Brenda W J H
authors.initials: BW
authors.lastname: Penninx
authors.forename: Mark A
authors.initials: MA
authors.lastname: van Buchem
authors.forename: Johan H C
authors.initials: JH
authors.lastname: Reiber
authors.forename: Serge A R B
authors.initials: SA
authors.lastname: Rombouts
authors.forename: Julien
authors.initials: J
authors.lastname: Milles
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000502:physiology; D055815:Young Adult