Christine Ecker wrote:

I would like to export cortical thickness measures and compare the data across subjects in a vertex-by-vertex fashion.

Please could you confirm that similar functions such as mri_glmfit are based on the parameters in template space e.g. lh.thickness.fsaverage.mgh and not on the parameters in native space e.g. lh.thickness.

yes

So for a group comparison I would have to export the files in template space (e.g. lh.thickness.fsaverage.mgh) and could then map the output back onto the template?

not sure what you mean, the thickness.fsaverage.mgh is already in the template space

Also, why are the parameters not the same in native and template space?

Not sure what you mean. Can you give an example?

Finally, in order to compare groups on the basis of the parcellated regions (e.g. lh.aparc.stats). Are parameters such as area, volume, curvature etc comparable across groups or would they still have to be corrected for whole-brain volume?

If you are going to correct for brain or head size, then you'd do it for volume, thickness, and surface area measures, but not necessarily curvature.

doug

I would be very grateful if you could help me further.

Thank you!

---

Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer