Hello, 
I have several studies displaying multiple equivalent contrasts of interest (for ex Study 1a and Study1b) so I want combine them to have one contrast of interest per study, taking account dependency btw the different contrasts within a study (resulting in Study 1). 

So I pre-processed Study1a and Study1b. Then I have understand that I must combine these two. So I clicked on "combine images" and I tried to combine 4 files: t_upper study 1a, t_upper study 1b, t_lower study 1a, t_lower study 1b. Am I right ?
It created a var_reduced file with only the number "1" inside, so I suppose that I miss something...

Someone could help me please ?

Thanks !!
Layla

Dear Layla, 

My previous answer about considering different contrast from the same study as separate studies only works if the group of subjects of comparison is not exactly the same (eg. two different groups of patiens against the same group of controls). My apologizes for that. 

The new version of SDM doesn't allow to combine this kind of images; so if the group of subjects is the same in all contrast for a study, you should choose the one that best fits your criteria.

Kind Regards,
Lydia