Dear FSL experts,
I have a question for performing FSL-VBM (3 groups * 3 time point).
1. To make template, do I have to select same number of images from 3 time
point as well as 3 group?
2. I have 3 diagnostic group and each subject has 3 images which were get
different time. My hypothesis is that GM intensity will be decreased across
the time ( 1 vs 0 vs -1 for linear decline)and the slop of decrease will be
different among 3 groups (1 vs 1 vs -2: former 2 groups will not be
different but GM intensity of 3rd group will be more decreased.) and there
will be group by time interaction. But to make design matrix (for main
effects and group by time interaction) is not easy for me.
If each group has 3 subject, I think design matrix like below. But I'm not
sure it is correct and don't know the matrix for group by time interaction.
3. And do I have to make group.dat file which consist of nine 1s, nine 2s,
nine 3s?
I'd be very happy if I can hear any comment.
thanks,
bsjeong
sj1 sj2 sj3 t1 t2 t3 time
group
gr1_sj1_t1 1 0 0 1 0 0 1
1
gr1_sj1_t2 1 0 0 0 1 0 0
1
gr1_sj1_t3 1 0 0 0 0 1 -1
1
gr1_sj2_t1 0 1 0 1 0 0 1
1
gr1_sj2_t2 0 1 0 0 1 0 0
1
gr1_sj2_t3 0 1 0 0 0 1 -1
1
gr1_sj3_t1 0 0 1 1 0 0 1
1
gr1_sj3_t2 0 0 1 0 1 0 0
1
gr1_sj3_t3 0 0 1 0 0 1 -1
1
gr2_sj1_t1 1 0 0 1 0 0 1
-2
gr2_sj1_t2 1 0 0 0 1 0 0
-2
gr2_sj1_t3 1 0 0 0 0 1 -1
-2
gr2_sj2_t1 0 1 0 1 0 0 1
-2
gr2_sj2_t2 0 1 0 0 1 0 0
-2
gr2_sj2_t3 0 1 0 0 0 1 -1
-2
gr2_sj3_t1 0 0 1 1 0 0 1
-2
gr2_sj3_t2 0 0 1 0 1 0 0
-2
gr2_sj3_t3 0 0 1 0 0 1 -1
-2
gr3_sj1_t1 1 0 0 1 0 0 1
1
gr3_sj1_t2 1 0 0 0 1 0 0
1
gr3_sj1_t3 1 0 0 0 0 1 -1
1
gr3_sj2_t1 0 1 0 1 0 0 1
1
gr3_sj2_t2 0 1 0 0 1 0 0
1
gr3_sj2_t3 0 1 0 0 0 1 -1
1
gr3_sj3_t1 0 0 1 1 0 0 1
1
gr3_sj3_t2 0 0 1 0 1 0 0
1
gr3_sj3_t3 0 0 1 0 0 1 -1
1
|