Hi,
In my whole-brain analysis, task A minus task B identified significant activation in insula. On the other hand, I have a specific hypothesis in amygdala with respect to task C, and, using a apriori defined amygdala mask (a sphere defined from a relevant study), small-volume correlation (svc) showed a significant cluster within amygdala (peak at x2/y2/z2).
I want to examine whether the functional connectivity from insula to amygdala was also enhanced in task A compared with task B. To this end, I performed PPI analysis using insula as seed. Then, for the PPI contrast “Task A > Task B”, I want to performed svc in amygdala. For the amygdala mask here, there are 2 options: (1) the a priori defined amygdala mask, and (2) an r=6 sphere centred at x2/y2/z2.
Any suggestion for which one is better or makes more sense?
All the best,
Manuel
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