Oracle Compound Decision Rules for False Discovery Rate Control in fMRI studies
Abstract
The recent advance on functional magnetic resonance imaging (fMRI) allows scientists to assess functionality of the brain by measuring the response of blood flow to one or multiple types of stimuli. The analysis of fMRI studies is a very challenging high dimensional problem due to the fact that the statistical analysis will be applied to the measurements from huge volume of voxels. Based on the most recent development of the oracle false discovery rate, this thesis proposes three new approaches to the analysis of the fMRI studies. They are in the areas of 1) noise suppression by wavelet based Oracle False Discovery Rate (OFDR) threshholding; 2) voxel-based signal extraction with Enhanced Oracle False Discovery Rate (EOFDR); 3) group-based signal extraction using Brain-Map-Constrained adaptive oracle False Discovery Rate Approach. The simulation studies show improved performance of the proposed approaches compared to some existing competitive approaches. The proposed approaches are applied to fMRI studies to demonstrate practical usage.
Description
Keywords
Denoising, False discovery rate, Functional Magnetic Resonance Imaging, Group analysis, Multiple testing, Wavelet