Hi Alfonso,

thank you very much for the answer. It helped a lot. 
I will try to bother you with one more question.
I am doing the ROI-to-ROI analysis.
How does CONN deal with negative correlation coefficients (anticorrelations)? Are just absolute values taken in the connectivity matrix? The question bothers me because of the interpretation of the colors (blue or red). It surely plays a role if I correlate a covariate to positive CCs or negative CCs, it could switch the colors and then it would be a mess to interpret. 
Am I right to suppose that only postive CCs are allowed?

Thanks again for your help,
best,
Jan