Dear AFNI experts,

I´m sorry to come back to this topic again but I still have some questions regarding obliquity.

Both our anatomical and functional dicom data are differently oblique. That´s why I decided (of course after great help from the message board) to oblique the anatomy to match the epi with

3dWarp -card2oblique epi+orig prefix anattoepi anat+orig

We have 3 different paradigms in one scan session and I actually thought that it doesn´t matter which functional data I use for the 3dWarp command since the functional file is not changed and since the functional file of paradigm 1 has the same oblique transformation matrix than the functional data of paradigm 2 and 3. I expected to get the same result no matter if I do

1.) preprocessing of all paradigms (all subjects) using 3dWarp just once
2.) preprocessing of all paradigms using 3dWarp 3 times

But I noticed slight differences when I looked at the statistical files or the group analysis result (ttest). Can anybody give me some hints why it is like that and which way of preprocessing might be better ( 1.) or 2.) )! I would be grateful for any help!

Thank you very much in advance!

Beate