Dear McLaren,

I tried gPPI, but the result was very different from the one of the conventional PPI in SPM8. Because you demonstrated the similarity between two results. I am very curious why I've not a strange one.

Please find the attached for the PPI structure that I used.
The design includes 12 regressors of interest and 14 regressors (8 motion params + 6 compcor) for motion artifacts.
I tried to test the difference between the 3rd and the 1st regressors, and ran the conventional PPI for the same VOI and contrast.

The results are different, not just in different scales but only loosely correlated (r=0.36).

Should you need more details to answer my question, please let me know!

Best,
-SG