Hi list, 
please could you check my design

I have baseline (no treatment for all groups) and post (treatment for all groups)
two groups of treatment: drug vs. placebo
two groups of subjects: young vs. elderly.

I would like to verify the effect of drug vs placebo, taking in account (age groups) and possible interaction.

I have done:

MRI/fMRI windows
all subjects in with two longitudinal sessions (session1: pre, session2: post) 

second covariates window:
- Subjects ---> 1 x N subjects  [1 1 1 1 1 1 1 1 1 1 1]
- Treatment --> 1 for drug, -1 for placebo, therefore [1 1 -1 1 -1 -1 -1 1 -1 1]
- Aging ---> 1 for young, -1 for elderly, therefore [1 1 1 1 1 -1 -1 -1 -1 -1]

For second level analysis, I have selected on left panel: Subjects, Treatment, Aging.

Is this procedure corrected?

Thanks

Kind regards