[Freesurfer] How to avoid overlaps between volume labels?

Hello,

With FreeSurfer v4.5, I have three functionally localized surface labels (A.label, B.label, C.label), and converted this label to volume by using mri_label2vol with --proj. I now have three volume labels, A.mgz, B.mgz, and C.mgz.

Because these three labels are adjacent to each other, [A.mgz and B.mgz] and [B.mgz and C.mgz] share many voxels, and [A.mgz and C.mgz] also share a small number of voxels, while there is no overlap in the surface labels.

I'd like to make these volume labels independent by somehow creating boundary into the volume so that each volume labels never share any voxels. What would be the best way to do so? Is there anything I can do using a command line?

Best, Yuko Yotsumoto