There are not any restrictions, just do the same as you would for a non-paired analysis. In any event, you are creating a linear model y = a +b1*x1 + b2*x2 ... where y is the input (paired diff) and x1, x2, etc, are your factors. You are the one who knows your data and what models would be appropriate
On 10/31/19 12:41 PM, Jose Graterol wrote: > > External Email - Use Caution > > My doubt is, if it is possible to use a FSGD file to add variables to > a --paired-diff analysis. If it is, what would be the right way to > format the FSGD file. > > Thanks in advance. > > On Wed, Oct 30, 2019 at 3:01 PM Greve, Douglas N.,Ph.D. > <dgr...@mgh.harvard.edu <mailto:dgr...@mgh.harvard.edu>> wrote: > > I don't understand. What per hemisphere variable? > > On 10/25/2019 3:15 AM, Jose Graterol wrote: >> >> External Email - Use Caution >> >> Thanks for your answer. A follow up question: >> How should I then specify the variable's values per hemisphere >> while making the FSGD file if I want to add covariates when >> running mri_glmfit? >> >> Thanks in advance. >> >> On Fri, Oct 25, 2019 at 12:18 AM Greve, Douglas N.,Ph.D. >> <dgr...@mgh.harvard.edu <mailto:dgr...@mgh.harvard.edu>> wrote: >> >> If you are trying to determine whether the hemispheres are >> different, >> then you need to do the subtraction between the hemis (ie, the >> --paired-diff). If you want to look at the hemispheres >> separately, then >> don't combine them in a single file >> >> On 10/21/19 4:58 AM, Jose Graterol wrote: >> > >> > External Email - Use Caution >> > >> > Thanks for your answer. >> > >> > I want to correlate TMS values in 17 stroke patients. >> Following the >> > instructions provided to Anders in this link >> > >> >> https://www.mail-archive.com/search?l=freesurfer@nmr.mgh.harvard.edu&q=subject:%22%5C%5BFreesurfer%5C%5D+flipping+surface+data%22&o=newest&f=1 >> >> > I created the --y file that joins the affected hemispheres >> together >> > and the unaffected hemispheres together. I omitted the >> --paired-diff >> > flag. When I run mri_glmfit with --fsgd it asks for 34 >> inputs. I am >> > guessing those are for the 34 hemispheres of the patients >> in the order >> > mentioned in my first email. Would this be the right way to >> correlate >> > the variables? >> > >> > In short, I am trying to test if there is a difference in >> cortical >> > thickness, while adding covariates, between the affected and >> > unaffected hemispheres in stroke patients. >> > >> > Thanks in advance >> > >> > On Fri, Oct 18, 2019 at 3:57 PM Greve, Douglas N.,Ph.D. >> > <dgr...@mgh.harvard.edu <mailto:dgr...@mgh.harvard.edu> >> <mailto:dgr...@mgh.harvard.edu >> <mailto:dgr...@mgh.harvard.edu>>> wrote: >> > >> > What are you trying to test? Usually you don't have lh >> and rh in >> > the same glm >> > >> > On 10/17/19 7:09 AM, Jose Graterol wrote: >> >> >> >> External Email - Use Caution >> >> >> >> Dear Freesurfer Community, >> >> >> >> I have a question regarding the formatting of the FSGD >> file while >> >> doing an analysis with Xhemi. >> >> First the --y file was created as previously explained >> in another >> >> discussion >> >> >> >> (https://www.mail-archive.com/freesurfer@nmr.mgh.harvard.edu/msg63965.html). >> >> That is, mris_preproc with --xhemi and no --fsgd flag. >> >> >> >> If I understood correctly, that would create a mgh >> file with the >> >> following order: sub01lh, sub01rh, sub02lh, sub02rh... >> >> Then the FSGD file while running mri_glmfit would be: >> >> GroupDescriptorFile 1 >> >> Title xxx >> >> Class sub >> >> Variables var1 >> >> Input sub01lh sub var1_lh_sub01 >> >> Input sub01rh sub var1_rh_sub01 >> >> Input sub02lh sub var1_lh_sub02 >> >> Input sub02rh sub var1_rh_sub02 >> >> >> >> Would this be correct? If so, what would be the best >> case for >> >> specifying a variable like age? Just repeating the >> value 2 times? >> >> >> >> As always, thanks in advance >> >> >> >> Kind Regards >> >> >> >> José >> >> >> >> >> >> _______________________________________________ >> >> Freesurfer mailing list >> >> Freesurfer@nmr.mgh.harvard.edu >> <mailto:Freesurfer@nmr.mgh.harvard.edu> >> <mailto:Freesurfer@nmr.mgh.harvard.edu >> <mailto:Freesurfer@nmr.mgh.harvard.edu>> >> >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> > >> > _______________________________________________ >> > Freesurfer mailing list >> > Freesurfer@nmr.mgh.harvard.edu >> <mailto:Freesurfer@nmr.mgh.harvard.edu> >> <mailto:Freesurfer@nmr.mgh.harvard.edu >> <mailto:Freesurfer@nmr.mgh.harvard.edu>> >> > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> > >> > >> > _______________________________________________ >> > Freesurfer mailing list >> > Freesurfer@nmr.mgh.harvard.edu >> <mailto:Freesurfer@nmr.mgh.harvard.edu> >> > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> <mailto:Freesurfer@nmr.mgh.harvard.edu> >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
