Hi surfers: I have a two questions. 1) how does freesurfer calculate ?h.sulc file and ?h.curv. Are they calculated after gray/white/csf segmentation? Are they calculate based on gray/white boundary? So, difference between ?h.sulc or ?h.curv will directly come from white matter change, right? 2) what's the difference between ?h.sulc and ?h.curv? In terms of sulcal structure, does ?h.sulc indicate sulcal depth and ?h.curv somehow indicate sulcal width? To me, from the display, ?h.sulc seems a smoothed version of ?h.curv. From some reference, I know .sulc is also called average convexity, so is the convexity for each vertex averaged within a small region or is it averaged through the whole hemisphere brain surface? Thanks much for your help! BestJing