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