title: Functional brain networks: great expectations, hard times and the big leap forward.
abstract: Many physical and biological systems can be studied using complex network theory, a new statistical physics understanding of graph theory. The recent application of complex network theory to the study of functional brain networks has generated great enthusiasm as it allows addressing hitherto non-standard issues in the field, such as efficiency of brain functioning or vulnerability to damage. However, in spite of its high degree of generality, the theory was originally designed to describe systems profoundly different from the brain. We discuss some important caveats in the wholesale application of existing tools and concepts to a field they were not originally designed to describe. At the same time, we argue that complex network theory has not yet been taken full advantage of, as many of its important aspects are yet to make their appearance in the neuroscience literature. Finally, we propose that, rather than simply borrowing from an existing theory, functional neural networks can inspire a fundamental reformulation of complex network theory, to account for its exquisitely complex functioning mode.
authors.affiliation: Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain papodav@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Papo
authors.affiliation: Faculdade de Cîencias e Tecnologia, Departamento de Engenharia, Electrotécnica, Universidade Nova de Lisboa, Lisboa, Portugal Innaxis Foundation and Research Institute, Madrid, Spain.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Zanin
authors.affiliation: Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain.
authors.forename: José Angel
authors.initials: JA
authors.lastname: Pineda-Pardo
authors.affiliation: Istituto dei Sistemi Complessi, CNR, Florence, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Boccaletti
authors.affiliation: Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain Complex Systems Group, Universidad Rey Juan Carlos, Móstoles, Spain.
authors.forename: Javier M
authors.initials: JM
authors.lastname: Buldú
mesh_terms: D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology*; D063132:Connectome; D006801:Humans; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D009488:Neurosciences / Q000379:methods* / Q000639:trends
keywords: complex networks theory; efficiency; functional neuroimaging; robustness; small-world; synchronizability