Hi Donna and Suzy,
I think Bob's warning also mentioned that the mask is on a coarse grid, and hasn't been validated on any data. In a nutshell, "use responsibly" is good advice.
On the other hand, as a rough mask, it's incredibly handy. Alex Clark repaired the link, so it's now possible to read all about TTatlas+tlrc at:
[
afni.nimh.nih.gov]
Sally