Dear FSL experts,
I have two groups of subjects and I want to study the difference between the groups using the command :
randomise -i 4Dmerged.nii.gz -vw -m mask.nii.gz -d design.mat -t design.con -n 5000 -T
1. In order to study the difference between the groups without covriates. I used in my design the following:
1 0
1 0
1 0
.
.
.
0 1
0 1
0 1
.
.
.
etc
2. I want to include age covariate: I demeaned age between the groups and included it in a third column in the design.
3. I want to include age and gender covariates: I included the demeaned age in a third column of the design, and I have created a fourth column and gave (male=1, female=0).
Regarding this analysis, are there nay rules to choose (0, 1 ) for categorical variables (e.g. male/female). When I gave one for male, and zero for female, I found difference between the groups. If I choose Zero for male and one for female, the difference disappear. Why this happen? How this can be explained?
I highly appreciate your valuable comments!
John
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