This one's for the stats experts.
I'm doing a 3 group VBM analysis and want to explore the correlations
between GM x "score", and their interactions.
Could this be addressed in spm5 with a full factorial model?
I imagine entering GM regressors and 3 "score" regressors thus:
[GM1 GM2 GM3 ScoreG1 ScoreG2 ScoreG3]
and exploring main effects with:
[0 0 0 1 1 1] positive and [0 0 0 -1 -1 -1] negative correlation between
"score" and GM in all three groups.
and interactions (looking for different regression slopes, Beta) with
[0 0 0 1 -0.5 -0.5] Beta 1 > Beta2 , Beta3, etc.
Does this make sense?
Happy Holidays!
Regards - Mike
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