Dear FreeSurfer Experts,

I'm trying to follow the steps described in the univeriate LME for longitudinal data (https://surfer.nmr.mgh.harvard.edu/fswiki/LinearMixedEffectsModels). Could you explain how you did this step: "The qdec.table.dat file was then used to collect volumetric data for all subjects within the Freesurfer's Qdec interface. This resulted in a new Qdec table which had the previous columns plus three new columns."

I followed the instructions with mri_preproc and mri_surf2surf but when I then open qdec to obtain the volumetric data for (in my case) BA45 it always gives out the error "Error in Analyze: Coudln't open /path_to_subject_base/lh.thickness.fwhm0.templatename.mgz or .mgh file" I understand that it can't find that file because it isn't there.

Which steps do I additionally need to perfom to be able to be able to obtain said volumetric data. Is there an extra turorial or walkthrough for that?

Cheers, Clara