Dear experts,
I have a question regarding positive vs negative PPi interpretation. I ran two PPI analyses on the same data using the exactly same contrast (CS+ vs CS-) and seed region (left amygdala coordinates -24 -2 -20): one with positive and one with negative interaction terms.
When doing group comparisons, I find significant activations in the exact same region (i.e. left insula -38 6 14) for both positive and negative PPIs, although activation parameters are different.
Is this normal ? How can I explain this (It would make sense to me if the activations were in the same region but not in the exact same peak voxel) ?
Thanks in advance for your help
Best,