Hi AFNI gurus,

I'm a long time reader, but first time writing in :) I am fairly comfortable using AFNI for individual subject analyses, but am a little confused now that I have moved over into a group analysis. Here's my situation and question:

I have performed a paired-samples t-test using 3dttest. When I open the AFNI GUI to see the map generated by this t-test, I select a tlrc'ed brain for the underlay, and then the name of the fitt file that was generated by 3dttest for the overlay. Then, I click on the "define function" button. Here is where I run into trouble: I'm not sure which subrick to select for the overlay, and which subrick to select for the threshold. There are two subricks in my fitt file, and I realize that subrick 0 is the "intensity", and subrick 1 is the "student t-test", but I am not sure what this exactly means, and which subrick to select for which item.

I of course have tried various combinations, just to see what it would look like, but I want to make sure that I am really looking at my t values correctly. Any guidance would be extremely appreciated :)

Thanks for your help,
Corianne