Hi Xue

Thanks for your detail explanation. I have some further questions:

1. For question 3, i followed the manual and setting window size for PET (5 5 5) and GM image (3 3 3), but the error still occurred.

2. For question 2, if i want to perform Model II correlation for task fmri series (original size = 3*3*3) and VBM GM volume image (original voxel size = 1*1*1) , which window size are reasonable for  each image modality ?

Many thanks!

Paul