Starting tomorrow (Fri), those using nmr-dev will notice a different talairach volume when checking/editing your talairach registration with tkregister2, eg,
tkregister2 --fstal --s bert
Previously, it used $SUBJECTS_DIR/talairach/mri/orig.mgz
Now, it uses $FREESURFER_HOME/average/mni305.cor.mgz
The old one was an average that was created a long time ago. The new one is the actual MNI 305 template that is used during automatic talairach registration done in recon-all.
We are changing the target because it is better to use the actual template than a surrogate. We are changing it now in anticipation of the (soon) new freesurfer release (!).
You should not need to modify your talairach.xfm based on the new target, as the true template and the surrogate are quite close to each other. You can see by comparing the old and new by running:
tkregister2 --fstal --s talairach
(you will not be able to save any edits :).
doug