Biomedical Engineering and Bioengineering Commons^™

Is First-Order Vector Autoregressive Model Optimal For Fmri Data?, Chee-Ming Ting, Abd-Krim Seghouane, Muhammad Usman Khalid, Sh-Hussain Salleh

Chee-Ming Ting

We consider the problem of selecting the optimal orders of vector autoregressive (VAR) models for fMRI data. Many previous studies used model-order of one and ignored that it may vary considerably across datasets depending on different data dimensions, subjects, tasks and experimental designs. Besides, the classical information criteria (IC) used, e.g. the Akaike IC (AIC) are biased and inappropriate for the high-dimensional fMRI data typically with small sample size. We examine the mixed results on the optimal VAR orders for fMRI, especially the validity of the order-one hypothesis by a comprehensive evaluation using different model selection criteria, over three typical …