Hi Christine,

Daniel and I did some thinking about this.

The short (but surely unsatisfactory) answer is that
your command :

adwarp -apar Ax_T1_SPGR+tlrc -dpar ROIs+acpc -prefix ROIs

applies the ORIG to TLRC transformation to the ACPC
dataset. The adwarp program does not somehow figure
out that the ACPC is at a halfway point. That is to say,
it does not do anything special about ACPC vs. ORIG
input.

So that leaves some pondering of options like:

- try to check for this situation and apply just the needed
part of the transformation within adwarp

- come up with an alternate way to transform the data
(there are a few possibilities here)

- start with points in the ORIG space data

Exactly what was your method for populating the
datasets with those points?

- rick