Dear Experts,

I am going to average data from multiple subjects' surfaces to average surface of my study, obtained by mris_make_average_surface.

The problem is that when I am testing this with simply one subject as input:

#1 Create surface data for subject 1 mri_vol2surf --src ./DATA.img --src_type analyze --reg ./register.dat --hemi rh --o ./DATA.w --out_type w

#2 Turn w to curv mri_surf2surf --srcsubject Subject1 --sval ./DATA.w --sfmt w --trgsubject Subject1 --tval rh.DATA.curv --tfmt curv --hemi rh

#3 average the one subject to group brain mris_average_curvature -o AverageSurface DATA.curv rh sphere.reg Subject1 DATA_on_AverageSurface.curv

I get a different result (kind of smoothed result, much more close-to-zero data points around the higher values), compared to when I simply

#2 Turn w to curv , but now directly to AverageSurface mri_surf2surf --srcsubject Subject1 --sval ./DATA.w --sfmt w --trgsubject AverageSurface --tval rh.DATA.curv --tfmt curv --hemi rh

Why? If there is automatic smoothing in mris_average_curvature, can this be turned off?

best regards, Simo Vanni