title: Sparse dictionary learning of resting state fMRI networks.
abstract: Research in resting state fMRI (rsfMRI) has revealed the presence of stable, anti-correlated functional subnetworks in the brain. Task-positive networks are active during a cognitive process and are anti-correlated with task-negative networks, which are active during rest. In this paper, based on the assumption that the structure of the resting state functional brain connectivity is sparse, we utilize sparse dictionary modeling to identify distinct functional sub-networks. We propose two ways of formulating the sparse functional network learning problem that characterize the underlying functional connectivity from different perspectives. Our results show that the whole-brain functional connectivity can be concisely represented with highly modular, overlapping task-positive/negative pairs of sub-networks.
authors.affiliation: Section of Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, Philadelphia, USA.
authors.forename: Harini
authors.initials: H
authors.lastname: Eavani
authors.affiliation: Section of Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, Philadelphia, USA.
authors.forename: Roman
authors.initials: R
authors.lastname: Filipovych
authors.affiliation: Section of Biomedical Image Analysis, Department of Radiology, University of Pennsylvania, Philadelphia, USA.
authors.forename: Christos
authors.initials: C
authors.lastname: Davatzikos
authors.affiliation: Brain and Behavior Laboratory, Department of Psychiatry, University of Pennsylvania, Philadelphia, USA.
authors.forename: Theodore D
authors.initials: TD
authors.lastname: Satterthwaite
authors.affiliation: Brain and Behavior Laboratory, Department of Psychiatry, University of Pennsylvania, Philadelphia, USA.
authors.forename: Raquel E
authors.initials: RE
authors.lastname: Gur
authors.affiliation: Brain and Behavior Laboratory, Department of Psychiatry, University of Pennsylvania, Philadelphia, USA.
authors.forename: Ruben C
authors.initials: RC
authors.lastname: Gur
keywords: K-SVD; Resting state fMRI; functional connectivity; sparse modeling