Hello, I'm a newbie in MRI and I'm running 2nd level ROI2ROI analyses in CONN on a sample of patients and matched controls. 

With difference group1 > group 2 or viceversa, contrast 1 -1 or -1 1, I get no significative results. 

If I set "Effect of groupPATIENTS" (Does the average connectivity within groupPATIENTS differ from 0, when estimated at the zero-level oh groupCONTROLS?), with contrast 0 1, I get several significant clusters. 

A colleague told me that it's basically because this way I'm just considering within-group connectivity, ignoring the control group. But if I run "Does the average connectivity within groupPATIENTS differ from zero", the results are completely different. 

So, what am I really doing with a 0 1 contrast? 

Thank you for your help.