Probably 0 1, since you are not interested in the offset. You would use one modality as input (y) and the other as the pvr. glmfit will then solve the model y = offset + slope*pvr at each voxel, fitting the offset and slope. You'll then want to test the slope doug
On 10/30/2013 11:24 AM, cel...@nmr.mgh.harvard.edu wrote: > Thank you. > For the contrast, if I don't enter any other regressor, then it will be 1 -1? > Celine > >> Hi Celine, use mri_glmfit with the --pvr option (pvr = per-vertex >> regressor) >> doug >> >> >> On 10/30/2013 10:20 AM, cel...@nmr.mgh.harvard.edu wrote: >>> Hi freesurfer team, >>> I am wondering if there would be a way to process a glm analysis between >>> 2 >>> surfaces from different modalities within one group of subjects. >>> >>> For example, within one population of patients, we would like to see if >>> there is a spatial relationship between cortical thickness and another >>> metrics (DTI metrics for example). What we have done so far is compute >>> the >>> mean cortical thickness for each parcellation, the mean FA for each >>> parcellation, and we did a linear regression with all the subjects of >>> our >>> group. >>> Would there be a way to do that at the vertex level instead of a whole >>> region level? From what I understood, when we use glmfit, the regressors >>> that we can put are single values like age, group, cognitive testing >>> etc, >>> but maybe not an entire surface? >>> Thanks a lot >>> >>> >>> Best, >>> Celine >>> >> -- >> 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 >> >> >> > -- 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.
