Hello,
I am performing an mri_glmfit analysis between my control and my clinical group, and I'm including age and total intracranial volume in the model.
However, I'd like to regress out the effects of gender, and I'm curious if the best approach to do this is to group my subjects by their gender (i.e. Have Class: MaleClinical, FemaleClinical, MaleControl, Female Control), or to add gender as a factor in the model (Make Variables: Age, ICV, and gender [ coded as 0 for female and 1 for male]).
My clinical population is primarily a male disorder (we have close to 10 females out of at total of 114 participants), so I feel like splitting them into groups would make a huge difference just based on that, and I'd honestly rather regress out the effects of gender rather than analyze them as variables of interest.
Please let me know what you think at your earliest convenience.
-Thomas
freesurfer@nmr.mgh.harvard.edu