title: Spatial Variance in Resting fMRI Networks of Schizophrenia Patients: An Independent Vector Analysis.
abstract: Spatial variability in resting functional MRI (fMRI) brain networks has not been well studied in schizophrenia, a disease known for both neurodevelopmental and widespread anatomic changes. Motivated by abundant evidence of neuroanatomical variability from previous studies of schizophrenia, we draw upon a relatively new approach called independent vector analysis (IVA) to assess this variability in resting fMRI networks. IVA is a blind-source separation algorithm, which segregates fMRI data into temporally coherent but spatially independent networks and has been shown to be especially good at capturing spatial variability among subjects in the extracted networks. We introduce several new ways to quantify differences in variability of IVA-derived networks between schizophrenia patients (SZs = 82) and healthy controls (HCs = 89). Voxelwise amplitude analyses showed significant group differences in the spatial maps of auditory cortex, the basal ganglia, the sensorimotor network, and visual cortex. Tests for differences (HC-SZ) in the spatial variability maps suggest, that at rest, SZs exhibit more activity within externally focused sensory and integrative network and less activity in the default mode network thought to be related to internal reflection. Additionally, tests for difference of variance between groups further emphasize that SZs exhibit greater network variability. These results, consistent with our prediction of increased spatial variability within SZs, enhance our understanding of the disease and suggest that it is not just the amplitude of connectivity that is different in schizophrenia, but also the consistency in spatial connectivity patterns across subjects.
authors.affiliation: Chester F. Carlson Center of Imaging Science, Rochester Institute of Technology, Rochester, NY; The Mind Research Network, Albuquerque, NM; sgopal@mrn.org.
authors.forename: Shruti
authors.initials: S
authors.lastname: Gopal
authors.affiliation: The Mind Research Network, Albuquerque, NM;
authors.forename: Robyn L
authors.initials: RL
authors.lastname: Miller
authors.forename: Andrew
authors.initials: A
authors.lastname: Michael
authors.affiliation: Department of Computer Science and Electrical Engineering, University of Maryland Baltimore County, Baltimore, MD;
authors.forename: Tulay
authors.initials: T
authors.lastname: Adali
authors.affiliation: Department of Computer Science, University of New Mexico, Albuquerque, NM;
authors.forename: Mustafa
authors.initials: M
authors.lastname: Cetin
authors.affiliation: The Mind Research Network, Albuquerque, NM;
authors.forename: Srinivas
authors.initials: S
authors.lastname: Rachakonda
authors.affiliation: Department of Psychiatry, University of New Mexico, Albuquerque, NM;
authors.forename: Juan R
authors.initials: JR
authors.lastname: Bustillo
authors.affiliation: Center for Applied and Computational Mathematics in the School of Mathematical Sciences, Rochester Institute of Technology, Rochester, NY;
authors.forename: Nathan
authors.initials: N
authors.lastname: Cahill
authors.affiliation: Chester F. Carlson Center of Imaging Science, Rochester Institute of Technology, Rochester, NY;
authors.forename: Stefi A
authors.initials: SA
authors.lastname: Baum
authors.affiliation: The Mind Research Network, Albuquerque, NM; Department of Computer Science, University of New Mexico, Albuquerque, NM; Department of Psychiatry, University of New Mexico, Albuquerque, NM; Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM.
authors.forename: Vince D
authors.initials: VD
authors.lastname: Calhoun
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001303:Auditory Cortex / Q000503:physiopathology; D001479:Basal Ganglia / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D005260:Female; D059907:Functional Neuroimaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D011618:Psychotic Disorders / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*; D066191:Sensorimotor Cortex / Q000503:physiopathology; D014793:Visual Cortex / Q000503:physiopathology; D055815:Young Adult
keywords: IVA; resting fMRI; schizophrenia; spatial variability