Can the overlay feature in freesurfer be used to overlay anatomic images? (or does the overlay image have to be spatial data).
 
I'm trying to overlay a EPI image over a T1 image, and the EPI volume is showing up as a yellow block. The EPI and the T1 mgz files were both generated by mri_convert from spm files.
 
Thanks,
 
Salil Soman
sal@bwh.harvard.edu