Dear FSL experts,
I would like to run 2 group analyses (with 3 demined covariables) on a DTI (tbss) data.
My matrix looks like this:
0.000000e+00 1.000000e+00 3.852140e-01 9.537659e-01 -9.333656e+00
1.000000e+00 0.000000e+00 3.852140e-01 -1.674370e+01 1.406663e+02
0.000000e+00 1.000000e+00 3.852140e-01 1.299210e+01 4.066634e+01
0.000000e+00 1.000000e+00 -6.147860e-01 5.766907e+00 -1.093337e+02
1.000000e+00 0.000000e+00 3.852140e-01 -1.746923e+01 -1.093337e+02
0.000000e+00 1.000000e+00 3.852140e-01 1.114678e+01 1.906663e+02
...and so on...
My contrasts (among others) are:
ev1 ev2 ev3 ev4 ev5 ev6
c1 1 -1 0 0 0 0
c2 -1 1 0 0 0 0
c3 1 0 0 0 0 0
c4 -1 0 0 0 0 0
c5 0 1 0 0 0 0
c6 0 -1 0 0 0 0
c7 0.5 0.5 0 0 0 0
c8 -0.5 -0.5 0 0 0 0
Am I correct to think that contrast 7 is testing if the overall FA mean (both groups together) is >0?
My c3 showed significant results so did my c5. But my c7 didn't... I was expecting that if g1 mean is >0 and g2 mean is >0 that my g1+g2 mean would also be >0. Where did I get wrong?
Regards,
Thais Minett
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