Universally Optimal fMRI Designs for Comparing Hemodynamic Response Functions

• Activity Number: 642
• Type: Contributed
• Date/Time: Thursday, August 7, 2014 : 10:30 AM to 12:20 PM
• Sponsor: IMS
• Author(s): Ming-Hung Kao*+
• Companies: Arizona State University
• Keywords: Experimental designs ; Functional magnetic resonance imaging ; Hadamard matrix ; Hemodynamic response function ; Universal optimality

Abstract

Functional magnetic resonance imaging (fMRI) is a noninvasive, pioneering brain mapping technology allowing us to study the inner workings of our brains. High-quality experimental designs are crucially important to the success of fMRI studies. These designs help to collect informative data to render precise and valid statistical inference. However, not much guidance is available on selecting good fMRI designs. Much work remains to be done in this area. In this work, we propose a novel type of fMRI designs for comparing hemodynamic response functions (HRFs), which are functions of time describing the effects of the mental stimuli presented to the experimental subject. These designs are very easy to generate. Under certain assumption, we also provide a theoretical proof on the universal optimality of the proposed designs. These designs thus optimize a very large class of statistically meaningful optimality criteria, and can yield very high statistical efficiency in practice. Our proposed designs help to enlarge the library of high-quality fMRI designs for experimenters to choose from.