title: Finding common task-related regions in fMRI data from multiple subjects by periodogram clustering and clustering ensemble.
abstract: We propose an innovative and practically relevant clustering method to find common task-related brain regions among different subjects who respond to the same set of stimuli. Using functional magnetic resonance imaging (fMRI) time series data, we first cluster the voxels within each subject on a voxel by voxel basis. To extract signals out of noisy data, we estimate a new periodogram at each voxel using multi-tapering and low-rank spline smoothing and then use the periodogram as the main feature for clustering. We apply a divisive hierarchical clustering algorithm to the estimated periodograms within a single subject and identify the task-related region as the cluster of voxels that have periodograms with a peak frequency matching that of the stimulus sequence. Finally, we apply a machine learning technique called clustering ensemble to find common task-related regions across different subjects. The efficacy of the proposed approach is illustrated via a simulation study and a real fMRI data set. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Statistics, University of Akron, Akron, OH, U.S.A.
authors.forename: Jun
authors.initials: J
authors.lastname: Ye
authors.affiliation: Department of Statistics and Statistical Laboratory, Iowa State University, Ames, IA, U.S.A.
authors.forename: Yehua
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Statistics, University of Georgia, Athens, GA, U.S.A.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Lazar
authors.affiliation: Department of Neuroscience, University of Georgia, Athens, GA, U.S.A.
authors.forename: David J
authors.initials: DJ
authors.lastname: Schaeffer
authors.affiliation: Departments of Psychology and Neuroscience, University of Georgia, Athens, GA, U.S.A.
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: McDowell
mesh_terms: D000465:Algorithms; D001921:Brain; D001931:Brain Mapping; D016000:Cluster Analysis; D006801:Humans; D008279:Magnetic Resonance Imaging
keywords: autocorrelation; ill-balanced data; multi-taper; periodogram; spectral analysis