27 Oct
2009
27 Oct
'09
4:28 p.m.
Hi everyone,
I was hoping you can clarify something for me.
I'm comparing two groups using CTA (in freesurfer). When I set up my model, I include age as a covariate of no interest. To do this, I include it as a variable in the fsgd, and in the contrast matrix, I regress out the effects of age, by setting the vectors to 0.
However, when I extract the results from the analysis (the thickness values), and graph them against age, I find that I have an interaction, or an age effect nonetheless.
Could you please shed some light on this for me?
Thanks,
Massih