Hi Aaron,

in general people find that correcting for ICV/TIV increases variance for thickness, as opposed to surface area and volume, which need it. So no, we don't usually scale.

cheers, Bruce On Tue, 5 Jun 2007, Goldman, Aaron (NIH/NIMH) [C] wrote:

Hi, regarding thickness analysis using Freesurfer data, I was wondering if it was recommended to use any kind of scaling (for example, to the subjects' overall average thickness). I'm interested regarding both node-by-node analysis using mris_glmfit, and region-based using the aparc.stats files.

Thanks,

-Aaron-