Dear FSL experts,

We have one group of subjects which we are scanning under different conditions/levels (longitudinal DTI). We would like to "compare every condition/level with every other one".

With reference to the example on the FSL website, it is not clear to me why it is necessary to include, in addition to subject means, one EV _less_ than the number of levels and then test for differences w.r.t. the mean.

So let's say we have 2 subjects (subj1-2) and 4 conditions (lev1-4) - see example on FSL website. Would it be correct to modify this example adding an EV (eg. as many additional EV as there are levels) and then simply test _all_ contrasts? Below are the matrices I would use in this case.

Thank you very much in advance for any help anyone  may be able to provide!

Nicola

- design.mat

EV1=subj1/EV2=subj2/EV3=lev1/EV4=lev2/EV5=lev3/EV6=lev4
1/0/1/0/0/0
1/0/0/1/0/0
1/0/0/0/1/0
1/0/0/0/0/1
0/1/1/0/0/0
0/1/0/1/0/0
0/1/0/0/1/0
0/1/0/0/0/1

- design.con
0/0/1/-1/0/0
0/0/1/0/-1/0
0/0/1/0/0/-1
0/0/0/1/-1/0
0/0/0/1/0/-1
0/0/0/0/1/-1

- design.fts
1/1/1/1