afni.nimh.nih.gov

Your second choice is correct. 3dresample only changes voxel sizes and field of view. Use 3dWarp to transform between Talairach and MNI space instead. See 3dWarp -help for more info and these previous postings for alternatives for transforming ROIs between these two template spaces.

http://afni.nimh.nih.gov/afni/community/board/read.php?1,137203,137206#msg-137206

http://afni.nimh.nih.gov/afni/community/board/read.php?1,70173,80922#msg-80922