title: Robust Identification of Partial-Correlation Based Networks with Applications to Cortical Thickness Data.
abstract: Insight into brain development and organization can be gained by computing correlations between structural and funtional measures in parcellated cortex. Partial correlations can often reduce ambiguity in correlation data by identifying those pairs of regions whose similarity cannot be explained by the influence of other regions with which they may both interact. Consequently a graph with edges indicating nonzero partial correlations may reveal important subnetworks obscured in the correlation data. Here we describe and investigate PC*, a graph pruning algorithm for identification of the partial correlation network in comparison to direct calculation of partial correlations from the inverse of the sample correlation matrix. We show that PC* is far more robust and illustrate its use in the study of covariation in cortical thickness in ROIs defined on a parcellated cortex.
authors.affiliation: Signal & Image Processing Inst., University of Southern California, Los Angeles, CA.
authors.forename: David
authors.initials: D
authors.lastname: Wheland
authors.affiliation: Signal & Image Processing Inst., University of Southern California, Los Angeles, CA; Brain Creativity Institute, University of Southern California, Los Angeles CA, USA.
authors.forename: Anand A
authors.initials: AA
authors.lastname: Joshi
authors.affiliation: Center for Magnetic Resonance, School of Psychology, University of Queensland, Brisbane, Australia.
authors.forename: Katie L
authors.initials: KL
authors.lastname: McMahon
authors.affiliation: Queensland Institute of Medical Research, Brisbane, Australia.
authors.forename: Narelle K
authors.initials: NK
authors.lastname: Hansell
authors.affiliation: Queensland Institute of Medical Research, Brisbane, Australia.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Martin
authors.affiliation: Queensland Institute of Medical Research, Brisbane, Australia.
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Wright
authors.affiliation: Laboratory of Neuro Imaging, Dept. of Neurology, UCLA School of Medicine, Los Angeles, CA, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.affiliation: Laboratory of Neuro Imaging, Dept. of Neurology, UCLA School of Medicine, Los Angeles, CA, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Shattuck
authors.affiliation: Signal & Image Processing Inst., University of Southern California, Los Angeles, CA.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Leahy
keywords: PC algorithm; brain networks; graphical Gaussian model; human connectome; partial correlation