Hi all,

this post was started a long time ago but I have some additional (related) questions that I cannot easily address.

I would need to run an SCV to further explore and characterize my results (using small preregistered ROIs, which I found as being significantly involved in the task when running some t-tests on the averaged beta weights as well as in the analysis from the whole brain ). To do this, I am currently applying a 3dttest++ and 3dClustSim to each of the small ROIs and looking at the clusters that survive an initial uncorrected threshold of .001. I have, however, some doubts about what I did so far:

First of all, I did not take into account the FWHM in these SCVs (nor in the other analysis, like on the averaged beta weights extracted from each ROI).
- Do you think my results would dramatically change if I take into account the individual FWHM?
- How can I implement FWHM in my analysis? I should do this at a group (3dttest++) or individual level (in 3dDeconvolve)? (I am very new to afni and I am still learning how to program: is there maybe a simple script one could share with me?). I am using 3dDeconvolve and 3dREMLfit for my first-level analysis.

- Is it correct to use ClustSim in a small volume (e.g. VTA)? I would think that a peak-level analysis (as SVC in SPM) would be more appropriate here. If this is correct, wherein the output one should look to find the (FWE correct) peaks?

Thanks a lot in advance for your kind help!

Silvia