Title: A functional mixed model for scalar on function regression with application to a functional MRI study
Authors: Luo Xiao - North Carolina State University (United States) [presenting]
Abstract: Motivated by a functional magnetic resonance imaging (MRI) study, we propose a novel functional mixed model for scalar on function regression. The model extends the standard scalar on function regression for repeated outcomes by incorporating random subject-specific functional effects. Using functional principal component analysis, the new model can be reformulated as a mixed effects model and thus easily fit. A test is also proposed to assess the existence of the random subject-specific functional effects. We evaluate the performance of the model and test via a simulation study, as well as on data from the motivating fMRI study of thermal pain. The data application indicates significant subject-specific effects of the human brain hemodynamics related to pain and provides insights on how the effects might differ across subjects.