title: A parsimonious statistical method to detect groupwise differentially expressed functional connectivity networks.
abstract: Group-level functional connectivity analyses often aim to detect the altered connectivity patterns between subgroups with different clinical or psychological experimental conditions, for example, comparing cases and healthy controls. We present a new statistical method to detect differentially expressed connectivity networks with significantly improved power and lower false-positive rates. The goal of our method was to capture most differentially expressed connections within networks of constrained numbers of brain regions (by the rule of parsimony). By virtue of parsimony, the false-positive individual connectivity edges within a network are effectively reduced, whereas the informative (differentially expressed) edges are allowed to borrow strength from each other to increase the overall power of the network. We develop a test statistic for each network in light of combinatorics graph theory, and provide p-values for the networks (in the weak sense) by using permutation test with multiple-testing adjustment. We validate and compare this new approach with existing methods, including false discovery rate and network-based statistic, via simulation studies and a resting-state functional magnetic resonance imaging case-control study. The results indicate that our method can identify differentially expressed connectivity networks, whereas existing methods are limited.
authors.affiliation: Department of Epidemiology and Biostatistics, University of Maryland, College Park, Maryland.
authors.forename: Shuo
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Biostatistics, University of Michigan, Ann Arbor, Michigan.
authors.forename: Jian
authors.initials: J
authors.lastname: Kang
authors.affiliation: Department of Epidemiology and Biostatistics, University of Maryland, College Park, Maryland.
authors.forename: Yishi
authors.initials: Y
authors.lastname: Xing
authors.affiliation: Department of Epidemiology and Biostatistics, University of Maryland, College Park, Maryland.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Wang
mesh_terms: D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology* / Q000473:pathology / Q000502:physiology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003198:Computer Simulation; D006801:Humans; D008959:Models, Neurological; D009422:Nervous System Diseases / Q000473:pathology*; D016571:Neural Networks, Computer; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology*
keywords: connectivity; fMRI; family-wise error; network; parsimony; statistical power