Thanks for your reply.

I apologize for not having described my question very clearly. The "smoothed" I mentioned refers to the option of SurfIce (Help->Preferences->Smooth Voxel-based images). The two panels in my previously posted figure were based on the same nifti file, but with the "Smooth Voxel-based images" option checked and unchecked, respectively. I was asking if the parameters of such "Smooth" built in Surfice can be adjusted. I do want to use Surfice as visualization  purpose only.

Hope this is clearer and look forward to your further help.

Thanks!