Dear Freesurfer experts,

I am reposting my question from early this week since it is not answered. Any help much appreciated.

My question is about the measure of pial surface area. Following a group comparison and correction in QDEC, I found a significant cluster (size: 760mm^2) when choosing area. pial as the measure. In order to plot group means in a bar graph, I extract numbers from the "cache.th20.neg.y.ocn.dat" file, but the average is less than 1. Why is the magnitude of supposed pial surface area so small? Is this actual or standardized measure ?

Karl