Dear FSL experts,
I am aware, that there are many posts dealing with the topic how to handle covariates. Due to the amount and specificity of all these answers I got a little bit confused, which design to choose.
To my study: I'm doing resting state analysis using dual regression. Due to some neuropsychological parameters I got two groups of people. Now I want to compare their resting state networks with each other and at the same time I want to exclude the effects of age, gender and education (like you would do in SPSS using an ANCOVA).
I'm using fsl GLM to create the desing.con and .mat. I read, that instead of defining the groups in the column "group" with 1 and 2s you should state 1 for all subjects and later define the groups via EV1 and EV2.
My design looks like:
Group Ev1 Ev2 Ev3(age) Ev4(gender) Ev5(education)
1 1 0 76 1 5
1 1 0 56 2 6
1 0 1 62 2 5
1 1 0 73 1 7
1 0 1 69 2 4
Contrasts were set to:
c ev1 ev2 ev3 ev4 ev5
c1 1 0 0 0 0
c2 0 1 0 0 0
c3 0 0 1 0 0
c4 0 0 0 1 0
c5 0 0 0 0 1
c6 1 -1 0 0 0
c7 -1 1 0 0 0
c1 and c2 display the Activity related to the groups, c3-5 show the effects of the separate covariates and c6 and 7 show what areas are more/less active in one group in comparison to the other.
I'm not sure, whether my thoughts on this were correct. Am I missing something? The main contrasts I would focus on are c6 and c7, because I want to know the activity between the two participant groups controled for the effects of age, gender and education.
I want to thank you alot for your help!
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