Modified test statistics by inter-voxel variance shrinkage with an application to f MRI.

ABSTRACT: Functional magnetic resonance imaging (f MRI) is a noninvasive technique which is commonly used to quantify changes in blood oxygenation and flow coupled to neuronal activation. One of the primary goals of f MRI studies is to identify localized brain regions where neuronal activation levels vary between groups. Single voxel t-tests have been commonly used to determine whether activation related to the protocol differs across groups. Due to the generally limited number of subjects within each study, accurate estimation of variance at each voxel is difficult. Thus, combining information across voxels is desirable in order to improve efficiency. Here, we construct a hierarchical model and apply an empirical Bayesian framework for the analysis of group f MRI data, employing techniques used in

SUBMITTER: Su SC 

PROVIDER: S-EPMC3159431 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature