The resting brain: unconstrained yet reliable.
Recent years have witnessed an upsurge in the usage of resting-state functional magnetic resonance imaging (fMRI) to examine functional connectivity (fcMRI), both in normal and pathological populations. Despite this increasing popularity, concerns about the psychologically unconstrained nature of the "resting-state" remain. Across studies, the patterns of functional connectivity detected are remarkably consistent. However, the test-retest reliability for measures of resting state fcMRI measures has not been determined. Here, we quantify the test-retest reliability, using resting scans from 26 participants at 3 different time points. Specifically, we assessed intersession (>5 months apart), intrasession (<1 h apart), and multiscan (across all 3 scans) reliability and consistency for both region-of-interest and voxel-wise analyses. For both approaches, we observed modest to high reliability across connections, dependent upon 3 predictive factors: 1) correlation significance (significantly nonzero > nonsignificant), 2) correlation valence (positive > negative), and 3) network membership (default mode > task positive network). Short- and long-term measures of the consistency of global connectivity patterns were highly robust. Finally, hierarchical clustering solutions were highly reproducible, both across participants and sessions. Our findings provide a solid foundation for continued examination of resting state fcMRI in typical and atypical populations.
Shehzad
Zarrar
Z
Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, NYU Child Study Center, New York, NY 10016, USA.
Kelly
A M Clare
AM
Reiss
Philip T
PT
Gee
Dylan G
DG
Gotimer
Kristin
K
Uddin
Lucina Q
LQ
Lee
Sang Han
SH
Margulies
Daniel S
DS
Roy
Amy Krain
AK
Biswal
Bharat B
BB
Petkova
Eva
E
Castellanos
F Xavier
FX
Milham
Michael P
MP
D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009415:Nerve Net / Q000502:physiology; D012044:Regression Analysis; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted