Hi KC
1. Volumes are typically correlated with TIV and so if you don’t care about TIV itself you probably want to include it as a nuisance variable (both cortical and subcortical) 2. Thickness does not show this correlation and typically does not need to be correlated. Surface area does, and so it should be included (possibly to the 2/3 power, perhaps someone else can comment on this?). Not sure about curvature, but I would assume not as least to first order
Cheers Bruce
From: freesurfer-bounces@nmr.mgh.harvard.edu freesurfer-bounces@nmr.mgh.harvard.edu On Behalf Of Koustav Chatterjee Sent: Monday, November 22, 2021 12:03 AM To: Freesurfer support list freesurfer@nmr.mgh.harvard.edu Subject: [Freesurfer] Requesting to clarify doubts on data analysis
External Email - Use Caution Dear FreeSurfer team,
I have a few questions to clarify the confusion regarding data analysis.
1. For each subject, is it recommended to normalize the raw volumetric data by total intracranial volume? If so, is it true only for volumes of subcortical structures or, both subcortical and cortical structures? 2. In the same way, do I suppose to normalize
* Different cortical thickness with mean cortical thickness * Cortical surface area with total surface area * Different cortical curvature with mean cortical curvature Thank you for your time and help.
Regards, KC