Hi all, I have a question with regards to using the TIV as a covariate in comparing the subcortical volumes between the two cohorts. In particular I'm wondering:
1-Should you demean the TIV at all or not? 2-1-If you are using both age and TIV as your covariates, will it make sense to demean the age but not demean the TIV? 2-If you do demean each or both, should you demean these for each of the cohorts separately or use the mean of all of your subjects? I should add that the mean age of both of my cohort are pretty much the same and I'm just interested in seeing if there is a difference in the subcortical volumes between the two cohorts. Thanks for your advices in advance, Nas _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
