title: Shrinkage prediction of seed-voxel brain connectivity using resting state fMRI.
abstract: Resting-state functional magnetic resonance imaging (rs-fMRI) is used to investigate synchronous activations in spatially distinct regions of the brain, which are thought to reflect functional systems supporting cognitive processes. Analyses are often performed using seed-based correlation analysis, allowing researchers to explore functional connectivity between data in a seed region and the rest of the brain. Using scan-rescan rs-fMRI data, we investigate how well the subject-specific seed-based correlation map from the second replication of the study can be predicted using data from the first replication. We show that one can dramatically improve prediction of subject-specific connectivity by borrowing strength from the group correlation map computed using all other subjects in the study. Even more surprisingly, we found that the group correlation map provided a better prediction of a subject's connectivity than the individual's own data. While further discussion and experimentation are required to understand how this can be used in practice, results indicate that shrinkage-based methods that borrow strength from the population mean should play a role in rs-fMRI data analysis.
authors.affiliation: Department of Biostatistics, Johns Hopkins University, 615 N. Wolfe St., Baltimore, MD 21205, USA.
authors.forename: Haochang
authors.initials: H
authors.lastname: Shou
authors.affiliation: Department of Biostatistics, Johns Hopkins University, 615 N. Wolfe St., Baltimore, MD 21205, USA.
authors.forename: Ani
authors.initials: A
authors.lastname: Eloyan
authors.affiliation: Laboratory for Neurocognitive and Imaging Research, Kennedy Krieger Institute, 707 N. Broadway, Baltimore, MD 21205, USA.
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Nebel
authors.affiliation: Department of Biostatistics, Johns Hopkins University, 615 N. Wolfe St., Baltimore, MD 21205, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Mejia
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 601 North Caroline Street, Baltimore, MD 21287, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, USA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Pekar
authors.affiliation: Laboratory for Neurocognitive and Imaging Research, Kennedy Krieger Institute, 707 N. Broadway, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, USA.
authors.forename: Stewart
authors.initials: S
authors.lastname: Mostofsky
authors.affiliation: Department of Biostatistics, Johns Hopkins University, 615 N. Wolfe St., Baltimore, MD 21205, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Caffo
authors.affiliation: Department of Biostatistics, Johns Hopkins University, 615 N. Wolfe St., Baltimore, MD 21205, USA.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Lindquist
authors.affiliation: Department of Biostatistics, Johns Hopkins University, 615 N. Wolfe St., Baltimore, MD 21205, USA. Electronic address: ccrainic@jhsph.edu.
authors.forename: Ciprian M
authors.initials: CM
authors.lastname: Crainiceanu
mesh_terms: D001921:Brain / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005544:Forecasting; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D015233:Models, Statistical; D009415:Nerve Net / Q000502:physiology*; D012146:Rest
keywords: Connectivity analysis; Empirical Bayes; Measurement error correction; Resting-state fMRI; Shrinkage estimator