afni.nimh.nih.gov

> do the first 2 subbriks characterize the effect of subject, with the effect of BPRStot REGRESSED OUT?

"Regressing out" is not an accurate description. Instead, as I mentioned in my previous post, the sub-bricks #0 and #1 in your 3dttest++ output are for the intercept 'a' in the model above, which is the group average effect that is associated with the *average* value of X ('bprstot' in your case).

Gang