Dear all SPM experts
I have a question about how to construct suitable GLM design matrix and contrast for testing the relationship between regional gray matter volume and categorical variables? My experimental design as follows:
Research goal: To identify which brain region is correlated to specific categorical variables uniquely ? I have 5 clinical factors of each participants. Each clinical factor is "1" (indicated presence) and "0" (indicated absence).
Could I construct the design matrix as follows - Using multiple regression model in SPM :
(Using 5 participants as an example)
(Clinical factor 1) (Clinical factor 2) (Clinical factor 3) (Clinical factor 4) (Clinical factor 5)
1 1 0 0 0
1 0 0 0 0
1 0 1 0 0
0 1 1 1 0
0 0 0 0 1
0 0 0 0 0
and using the following contrast to testing which brain region is correlated with each clinical factors ?
contrast 1: 1 0 0 0 0
contrast 2: 0 1 0 0 0
contrast 3: 0 0 1 0 0
contrast 4: 0 0 0 1 0
contrast 5: 0 0 0 0 1
Best
Paul
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