Hi Jorge,
in the longitudinal stream all thickness files within each subject are in correspondence, so it would be sufficient to map all of them simultaneously (e.g. using the surfaces of the base) to fsaverage. Should save time and reduce variability.
Also (and this is true for both cross and longitudinal processing), it makes sense to intersect the cortex labels (first on a subject basis) map them to fsaverage and intersect again. Then use the intersected label for smoothing and ananlysis. This way you make sure you don't pollute your results with information from outside the cortex.
Best, Martin
On Tue, 2012-05-15 at 04:10 +0100, jorge luis wrote:
Hi all
I have some longitudinal data ready for the group analysis but I have a doubt:
Can I simply use the following command to resample all left hemisphere thickness maps onto the fsaverage surface (as in traditional cross-sectional analyses)?
mris_preproc --fsgd fsgd.txt --target fsaverage --hemi lh --meas thickness --out lh.fsgd_subj.mgh
Is there any change because of the data being longitudinal?
Thanks -Jorge
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer