mris_calc should do what you want (although the aseg is not zero in the cortex, so you will change the cortical labels)
cheers Bruce On Sat, 14 Apr 2012, Adil Javed wrote:
Hi, Is there a way to subtract segmented files in freesurfer? For example, aparc+aseg.mgz - aseg.mgz= aparc.mgz only? I am interested in looking only at the cortex. I find that label to volume conversion doesn't give me a nice segmented cortex, with some patchy areas of intensities lost.
thanks, AJ