Yes, you can use the --pvr flag (per-vertex regressor). You'll need to create a pvr file that is the exact same size as the file passed with --y. You will also need to account for the extra regressors in your contrast matrix. doug
On 12/22/2014 10:12 AM, Righart, Ruthger wrote: > Dear Freesurfers, > > I have a question about mri_glmfit for surface analyses. I have until > now used covariates which provided one value for each subject (e.g., > Age) but was wondering if it is possible to use covariates that have > different values for each vertex. > > I would like to perform a GLM analysis of thickness with another > surface-based measure as covariate. For example, Salat et al. (2009) > analysed the effect of age on GWR (ratio of gray matter - white matter) > and regressed out thickness at each vertex along the cortical surface > (i.e., an individual model for each vertex utilizing the thickness and > contrast). > > My question is: is this possible in mri_glmfit as applied in Freesurfer > and if so, how to do it? If not, are there other tools that might help > me out? > > Reference: Salat, Lee, van der Kouwe et al. (2009). Age-associated > alterations in cortical gray and white-matter signal intensity and gray > to white matter contrast. NeuroImage, 48, 21-8. > http://www.ncbi.nlm.nih.gov/pubmed/19580876 > > Thank you very much in advance for your time and help! > > Ruthger Righart > > _______________________________________________ > 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 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.
