Hi Alfonso, 

When we perform MVPA and analyse the differences in connectivity between conditions A and B across a number of PCs (e.g., 5), our result will indicate the differences in connectivity between these conditions in regions 1,2,3 (e.g.)  to the rest of the brain.

I have two questions regarding the MVPA:

1. But what if we are interested in common areas for these two conditions across these two conditions across the 5 MVPA measures? In other words, what areas for condition A and B are connected similar to the rest of the brain? Will a conjunction analysis answer this question (I cannot clear understand how CONN would compute it).

2. To account to individual performance for each of these conditions, I have behavioural covariate: covariate A and covariate B.

In case if we are looking at the differences in connectivity across 5 PCs, the contacts will be: 

between-subjects [0 1 -1] where AllSubjects (0), covariate A (1), covariate B (-1)
between conditions [1 -1] where condition A(1), condition B (-1)
between-measures contrast eye(5) for 5 PCs.

Am I correct?

But what the contrast will be if I would like to look at the commonalities across these two conditions (using these covariates) ?

I would greatly appreciate your help.
Thank you
alla