Hi,
My apologies if this is a re-posting; I wasn't sure it posted the first time.
I’m working on setting up a group analysis using FSL and I have some
questions about the higher-level analysis.
For the first-level analysis I have:
4 EV's : neut_init, neut_repeat, angry_init, angry_repeat
5 contrasts: all>baseline, neutral>angry, initial>repeat,
neut_init>neut_repeat, angry_init>angry_repeat
So for the second-level analysis, from what I understand, I should have four
separate group analysis (one for each parameter of interest): stress, no
stress, male, female. I would have 1 EV and 2 contrasts, mean and (-) mean,
for each of these groups.
Then for a third-level analysis, I would feed into feat the .gfeat’s from
the second-level and have 4 EVs also for stress, no stress, male, female.
The setup here would look something like:
Group EV1 EV2 EV3 EV4
S NS M F
Input 1 1 1 0 0 0
Input 2 1 0 1 0 0
Input 3 1 0 0 1 0
Input 4 1 0 0 0 1
Now for the contrasts, should I have a similar setup as above and include
f-tests for each contrast or should I setup a contrast for each pair
individually (that is: stress/male>stress/female, no stress/male>no
stress/female, stress/male>no stress/male, stress/female>no stress/female,
and each of their respective inverses)?
Any comments or help would be greatly appreciated.
Thanks,
Lin Nga
|