Hi all
 
I have two groups and i want to compare them with respect to connectivity differences.
 
How can I be sure about the direction of correlations in the difference image?

For example, if I code 1 -1, and I see only blue lines. Does this just mean that correlations are stronger for group 2 (irrespective of being positive or anticorrelations)?
 
In constrast, If I change to one-sided (positive), does this only show POSITIVE correlations for the same contrast, i.e. 1 -1, or does this only belongs to the group assignment? I think the latter is the case, because when I estimated -1 1, I get the same connections (shown as blue lines) as for the reversed contrast (red lines) if  turn to from one-sided (positive) to one-sided (negative)
 
it is difficult to intepret group differences if not group assignemt can have 2 signs but also correlation
 
Any ideas how to just visualize group differences for regions showing POSITIVE correlations?

Best wishes and Thanks

Lars