Dear all
I have resting state data from a group of patients and healthy controls
I have run a group concat and dual_regression using the RSNs from the concat and have run randomise on a number of the components with results showing a differeence between the two groups (patients > controls)
I'd like to see whether these changes are still present after accounting for differences in GM between the groups
I have set up a GLM matrix as below
PATIENTS CONTROLS GM EV
1 0 1
1 0 1
1 0 1
0 1 1
0 1 1
0 1 1
With contrasts
1 -1 0
-1 1 0
1 0 0
0 1 0
I have used the --vxl=3 option and --vxf= a 4D file with VBM GM_to_template_GM_mod files in the same order (patients then controls)
My questions are:
1. Is this correct?
2. If I want to specifically test the effect of GM on these changes, do I need to modify my GLM contrasts? i.e. add a 1 and -1 contrast for the EV3?
3. Should EV 3 be a voxel-dependent EV when using GLM_gui? Not sure as using randomise not FEAT
Thanks!
Monty
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