Apologies in advance for the naive question. Could you please  let me know what is the best way of transferring a nifti overlay volume to fsaverage, solely for illustration purposes? I think I should start by registering with fsaverage volume and then overlay with Freeview, but I'm not sure what tools from Freesurfer I should use for 1) between subject volume registration (nifti volume to fsaverage volume) 2) fsaverage volume to fsaverage surface.

Thank you,

James