I averaged the curvature of 20 hemispheres using mris_average_curvature, in the hopes of producing something like the average7 brain with major sulci and gryi displayed. This can be used to display group functional data. However, the resulting curvature looks nothing like average7. Seems that there is a lot of anatomical variability (after spherical registration) so the major structures are hard to see clearly in the average. How was the average7 surface created, and is there anything I am doing incorrectly? I have also tried this with 10 and 30 brains, and the results are similar. I have also averaged sulcal depth instead of curvature, and those maps are also not clean like average7.
% mris_average_curvature lh.curv lh smoothwm s1 s2 s3 s4...s20 lh.avg20.curv
thanks, Rutvik