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Hi FreeSurfer Experts,

I had a question regarding contrasts for univariate LME models.

I am interested in looking at the interaction of alcohol with change in volume 
across two time-points. Included in my model are covariates Gender, ICV, and 
Previous Drinking History.

My X matrix includes 7 columns:
Column 1 = 1s
Column 2 = time
Column 3 = alcohol
Column 4 = time*alcohol
Column 5 =  Gender
Column 6 = ICV
Column 7 = Previous Drinking History

My contrast is C = [0 0 0 1 0 0 0 ].

I have 4 different previous drinking history variables.  However, when I change 
column 7 with my different previous drinking history variables, the F and P 
values for the interaction are the same. Am I setting up my contrasts 


Jessica Hua
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