I have outputs from dual regression from a paired sample analysis and would now like to look at change in parameter estimate (for each pair) with change in a behavioral covariate. In FEAT outputs, I would usually add the subtract the COPE images for each pair, and add the VARCOPE images of the pair and feed a list of the subtracted COPE images into higher-level FEAT along with my behavioral covariate. For dual regression, I believe dr_stage2_* is the parameter estimates (COPE) image of each IC for subject but I was wondering how I can obtain the associate variance estimate (i.e. VARCOPE) images? I would like to subtract the pair of dr_stage2 parameter estimate images for a particular IC for a particular subject and then perform a regression with behavioral covariate of interest.