[Freesurfer] Performing GLM within a Mask Specified by Another GLM

Freesurfer Support,

Here is what I would like to do:

I have run a GLM on the entire cortex to determine whether there are significant differences in LGI between patients and controls. I then would like run a different GLM just with the clusters outputted from the previous GLM. It would seem that the best thing to do is to set a mask representing the clusters from the first GLM and then run the second GLM on the mask. Is this a reasonable thing to do? What steps/commands would I perform in order to do something like this?

Respectfully,

-Tim Hendrickson

Timothy Hendrickson Department of Psychiatry University of Minnesota Mobile: 507-259-3434 (texts okay)