Thanks Gang, I'll look into getting the R suite installed. Since typing "R" doesn't seem to do anything, I'm assuming it's not, despite how my AFNI install is automatically updated.

In the meantime though, what about using 3dRegAna? In particular, I see Example 1 in the manual (p. 15). Could I simply do a higher-order analysis, where I could invoke the relevant sub-briks of the already-modeled regression analysis bucket dataset?

In other words,

Warp each subject's statistical map of the modeled time series into common talairach space, and

-rows 44 would be the number of subjects
-columns 1 to designate a single age regressor, and where
-xydata 26 ../subject17/'regression+tlrc[12]'

where the sub-brick 12 is the coefficient of stim file A of a 26-year old subject

Would this yield a new statistical map of where the -stim_file coefficient of event "A" varies as a function of age?

If so, I could repeat this with both the other single stimulus coefficent, as well as the sub-brik corresponding to the coefficient of the linear contrast between event A and B.

If this is not kosher, is there another way I could use 3dRegAna?

Jim