Dear Freesurfer team,

I was a little confused by the recent e-mails about total GM and WM.

If you could help clarify the below mentioned, I would really appreciate it (am using freesurfer: stable 4 version). 

1) For cortical thickness analysis, there is no necessity to normalize each parcellation thickness value

2) For each GM and WM parcellation, we can norrnalize them with the total cerebral cortex volume and WM volume listed in the aseg.stats file

3) If  the talairach registration is not the best, its best to not normalize the volumes with the ICV value

Thanks so much,

Samantha