Narly,
qdec uses mri_glmfit to perform its analysis, and that is based on the General Linear Model, which is a type of analysis of covariance. Refer to these slides for more info:
https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial? action=AttachFile&do=get&target=freesurfer.groupanalysis.ppt
In the case of qdec, the measure is typically 'thickness', and you can select up to four regressors: two discrete (say, gender and diagnosis), and two continuous (say, age and left-hippo volume).
I think I answered your question, but Doug is the stats wizard, so he may chime-in, or you can restate your question.
Nick
On Thu, 2008-03-13 at 10:25 +0000, Narly A Golestani wrote:
Dear all,
Does qdec allow analyses of covariance, and if so, how? is it possible for example to test the effect of a regressor while controlling for the effect of a particular measure?
thanks, best, Narly. _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer