Dear FSL experts,
My question is about designing GLM for repeated measure ANOVA.
I have FA images from DTI scans for my subjcets. Each subject scanned in 5 different time points.
I want to design a GLM which shows areas with decreased FA between time point 1&2, 2&3, 3 &4 , 4&5 and also areas which shows linear decrease from time point 1 to time point 5.
I think for my first goal I should use ANOVA (1 factor-5 level), therefore for instance, for 2 subjects having scan in 5 time points, in order to show decrease FA between timepoint A&B, B&C, C&D and D&E, I should design:
Group EV1 EV2 EV3 EV4 EV5 EV6 EV7
subj1 subj2 time1 time 2 time 3 time 4 time5
1 1 0 1 0 0 0 0
1 0 1 1 0 0 0 0
1 1 0 0 1 0 0 0
1 0 1 0 1 0 0 0
1 1 0 0 0 1 0 0
1 0 1 0 0 1 0 0
1 1 0 0 0 0 1 0
1 0 1 0 0 0 1 0
1 1 0 0 0 0 0 1
1 0 1 0 0 0 0 1
Contrasts EV1 EV2 EV3 EV4 EV5 EV6 EV7
A-B 0 0 1 -1 0 0 0 ( shows decrease FA between timepoint 1&2)
B-C 0 0 0 1 -1 0 0
C-D 0 0 0 0 1 -1 0
D-E 0 0 0 0 0 1 -1
But I have no idea how I can show there is constant linear decrease from time point 1 to timepoint 5 ? I mean showing that FA1>FA2>FA3>FA4>FA5.
I would highly appreciate if any one could let me know if Iam correct for the first goal and how I can solve my second problem.
Best Regards,
Gelareh
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