Optimal and efficient designs for functional brain imaging experiments

This article concerns optimal experimental designs for neuroimaging studies in which the pioneering functional magnetic resonance imaging (fMRI) technology is used to investigate functions of the human brain. We develop analytical results for identifying designs that allow precise estimates of the contrasts between hemodynamic response functions (HRFs), each describing the effect of a mental stimulus over time. We also provide systematic methods for constructing optimal and very efficient designs, and show that fMRI designs obtained by relabeling the symbols of mm-sequences can be very efficient in comparing the HRFs.