Modular and hierarchically modular organization of brain networks
- 1 Centre for Speech, Language and the Brain, Department of Experimental Psychology, University of Cambridge, Cambridge, UK
- 2 Institute for Mathematical Sciences, Imperial College, London, UK
- 3 Behavioural and Clinical Neuroscience Institute, Department of Psychiatry, University of Cambridge, Cambridge, UK
Brain networks are increasingly understood as one of a large class of information processing systems that share important organizational principles in common, including the property of a modular community structure. A module is topologically defined as a subset of highly inter-connected nodes which are relatively sparsely connected to nodes in other modules. In brain networks, topological modules are often made up of anatomically neighboring and/or functionally related cortical regions, and inter-modular connections tend to be relatively long distance. Moreover, brain networks and many other complex systems demonstrate the property of hierarchical modularity, or modularity on several topological scales: within each module there will be a set of sub-modules, and within each sub-module a set of sub-sub-modules, etc. There are several general advantages to modular and hierarchically modular network organization, including greater robustness, adaptivity, and evolvability of network function. In this context, we review some of the mathematical concepts available for quantitative analysis of (hierarchical) modularity in brain networks and we summarize some of the recent work investigating modularity of structural and functional brain networks derived from analysis of human neuroimaging data.
Keywords: graph, near-decomposability, partition, fractal, cortex
Citation: Meunier D, Lambiotte R and Bullmore ET (2010) Modular and hierarchically modular organization of brain networks. Front. Neurosci. 4:200. doi: 10.3389/fnins.2010.00200
Received: 03 September 2010;
Paper pending published: 17 October 2010;
Accepted: 17 November 2010;
Published online: 08 December 2010.
Copyright: © 2010 Meunier, Lambiotte and Bullmore. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence: Edward T. Bullmore, Behavioural & Clinical Neuroscience, Institute Department of Psychiatry University of Cambridge, Herchel Smith Building for Brain & Mind Sciences Cambridge, Biomedical Campus Cambridge, CB2 0SZ. email@example.com