Positive not negative correlation maps in REST

Dear REST developers and experts
 
To the first, I really appreciate for providing a wonderful free software.
I've also attached the following query to the SPM mailing list.
 
I'm analysing seed-based (hippocampus) resting-state functional connectivity between patient and control groups by using spm8 and especially REST program.
The resulting zFC maps of include both positive and negative correlations.