0 1 1 will just be the mean of the slopes of var1 and var2. Looks like you want 0 1 -1 to look for the interaction.
doug Victoria Williams wrote: > Hello, > > I apologize if this is a very simple question, but how would you set up a > contrast matrix to look at the interaction of 2 variables on a measure? > For example, my fsgd file contains: > > class=1 > variables=2 > Input Subjid class var1 var2 > > When I tried using a contrast of 0_1_1 the significance map looks very > similar to the glm run only containing var1 (contrast_0_1). I thought > 0_1_1 was correct, but now I'm not so sure and would like to double check. > What I am interested in is how the interaction of var1 and var2 is > correlated with the brain measure per voxel. Is this possible with > mri_glmfit? > > I've checked the tutorials and scoured the internet as not to ask any > silly questions, but I'm having trouble finding anything helpful. > > Thanks in advance! > Tori > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 In order to help us help you, please follow the steps in: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
