Hi Arman, I have not followed the FSL thread, but you would only do this if you have a column of ones in your design matrix. Itdoes not imply that gender is being treated as a continous variable. A continuous variable for gender means that male=1 and female=2. This implies that you expect female thickness or slope vs age, etc, to be twice that of males. Probably this does not make sense. doug
On 05/14/2013 12:24 PM, Arman Eshaghi wrote: > Dear Doug and others, > > I'm sorry to hijack this thread. I noticed in FSL list that it has been > recommended to demean gender (and probably other categorical variables) > in GLM. As far as I understand, this implies treating a categorical > variable as a continuous one. However, I can also see that you recommend > not treating gender (and other categorical variables) as a continuous > variable in Freesurfer. I would much appreciate if someone can help me > to address this problem. I'm CC'ing FSL list so others may also help. > > All the best, > -Arman > > > On Tue, 2013-05-14 at 12:04 -0400, Douglas N Greve wrote: >> On 05/14/2013 10:05 AM, Tudor Popescu wrote: >> I thought that it would have. Are you coding age as a nuisance variable? >> Also, are you coding gender as a continuous variable? That is something >> you should not do. >>> >> -- >> Douglas N. Greve, Ph.D. >> MGH-NMR Center >> gr...@nmr.mgh.harvard.edu >> Phone Number: 617-724-2358 >> Fax: 617-726-7422 >> >> Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting >> FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 >> www.nmr.mgh.harvard.edu/facility/filedrop/index.html >> Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ >> >> _______________________________________________ >> 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. >> > > -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
