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Published Online: 20 September 2012

Functional Covariance Networks: Obtaining Resting-State Networks from Intersubject Variability

Publication: Brain Connectivity
Volume 2, Issue Number 4

Abstract

In this study, we investigate a new approach for examining the separation of the brain into resting-state networks (RSNs) on a group level using resting-state parameters (amplitude of low-frequency fluctuation [ALFF], fractional ALFF [fALFF], the Hurst exponent, and signal standard deviation). Spatial independent component analysis is used to reveal covariance patterns of the relevant resting-state parameters (not the time series) across subjects that are shown to be related to known, standard RSNs. As part of the analysis, nonresting state parameters are also investigated, such as mean of the blood oxygen level-dependent time series and gray matter volume from anatomical scans. We hypothesize that meaningful RSNs will primarily be elucidated by analysis of the resting-state functional connectivity (RSFC) parameters and not by non-RSFC parameters. First, this shows the presence of a common influence underlying individual RSFC networks revealed through low-frequency fluctation (LFF) parameter properties. Second, this suggests that the LFFs and RSFC networks have neurophysiological origins. Several of the components determined from resting-state parameters in this manner correlate strongly with known resting-state functional maps, and we term these “functional covariance networks”.

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cover image Brain Connectivity
Brain Connectivity
Volume 2Issue Number 42012
Pages: 203 - 217
PubMed: 22765879

History

Published online: 20 September 2012
Published ahead of print: 28 August 2012
Published in print: 2012
Published ahead of production: 5 July 2012

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Paul A. Taylor
Department of Radiology, UMDNJ-New Jersey Medical School, Newark, New Jersey.
Suril Gohel
Department of Radiology, UMDNJ-New Jersey Medical School, Newark, New Jersey.
Xin Di
Department of Radiology, UMDNJ-New Jersey Medical School, Newark, New Jersey.
Martin Walter
Department of Psychiatry, University of Magdeburg, Magdeburg, Germany.
Leibniz Institute for Neurobiology, Magdeburg, Germany.
Bharat B. Biswal
Department of Radiology, UMDNJ-New Jersey Medical School, Newark, New Jersey.

Notes

Address correspondence to:Paul A. TaylorDepartment of RadiologyUMDNJ-New Jersey Medical School30 Bergen StreetADMC Building 5, Suite 575Newark 07103, NJE-mail: [email protected]

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The authors declare no competing financial interests.

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