Dear Joaquim

I am conducing a meta-analysis with SDM. I am a little confused about combining multiple tasks in fMRI study (multiple tasks in the same sample) and combing subgroups in VBM study (multiple subgroups vs. the same set of control).

For example, in an fMRI study with 50 patients vs. 50 controls. Task A, task B, & task C were conducted in participants. We got 3 t-maps from publication, that is t-mapA (Task A between patients and controls ), t-mapB (Task B between patients and controls ), and t-mapC (Task C between patients and controls ). I used "combine images" button in SDM and get combined t-map, which would be used in the following meta-analysis. In the SDM table, the sample number for the combined t-map is n1=50 and n2=50. Is my understanding correct?

In the VBM study with 50 patients for subgroup1, 50 patients for subgroup2, and 50 controls, I got 2 t-maps from publication, t-map1 (subgroup1 vs. controls) and t-map2 (subgroup2 vs. controls). Also, I can combined the two t-maps, but what is the sample number for the combined t-map in SDM table? n1=100 n2=50? n1=50 n2=50? or n1=100 n2=100?

I'd really appreciate your help as I am very excited to use SDM for meta-analyzing SBM studies.
Thanks so much.

Fei