Hi Freesurfer users,
I ran a GLM vertex analysis testing an interaction between group and a task measure, and a few clusters popped up that survived correction. I extracted the mean thickness values at the clusters (using cache.th13.abs.y.ocn.dat) in order to plot these interactions in graph form. When I did this, the interactions look nonexistent, and there doesn't appear to be any relationships between my task measure and thickness in either group.
My FSGD file contains 4 groups (patients & controls with two different scanner sites), and my continuous variables are age and this task measure. I only have 15 patients and 15 controls, so my only thought so far is that my power is low, and these results are spurious.
My contrast file is: 0 0 0 0 0 0 0 0 0.5 0.5 -0.5 -0.5
Any insight would be greatly appreciated! Thank you!
Rachel