title: Functional Nonlinear Mixed Effects Models for Longitudinal Image Data.
abstract: Motivated by studying large-scale longitudinal image data, we propose a novel functional nonlinear mixed effects modeling (FNMEM) framework to model the nonlinear spatial-temporal growth patterns of brain structure and function and their association with covariates of interest (e.g., time or diagnostic status). Our FNMEM explicitly quantifies a random nonlinear association map of individual trajectories. We develop an efficient estimation method to estimate the nonlinear growth function and the covariance operator of the spatial-temporal process. We propose a global test and a simultaneous confidence band for some specific growth patterns. We conduct Monte Carlo simulation to examine the finite-sample performance of the proposed procedures. We apply FNMEM to investigate the spatial-temporal dynamics of white-matter fiber skeletons in a national database for autism research. Our FNMEM may provide a valuable tool for charting the developmental trajectories of various neuropsychiatric and neurodegenerative disorders.
authors.forename: Xinchao
authors.initials: X
authors.lastname: Luo
authors.forename: Lixing
authors.initials: L
authors.lastname: Zhu
authors.forename: Linglong
authors.initials: L
authors.lastname: Kong
authors.forename: Hongtu
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D000375:Aging / Q000473:pathology*; D001321:Autistic Disorder / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D015233:Models, Statistical; D017711:Nonlinear Dynamics; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D055815:Young Adult