there is not an easy way to do it. Probably the easiest thing to do is to create a separate session for each run. You can them analyze them under the same analysis name, then combine them together with isxconcat-sess, then do a one-sample group mean (--osgm) fixed effects analysis in mri_glmfit.
On 08/13/2017 09:53 PM, Taylor, Johnmark wrote: > Hello, > > I am trying to do a GLM analysis for a study in which I scanned each > participant twice. Currently, to combine the two scanning sessions I > am combining the runs from the two sessions into a single session > directory and applying per-session motion correction, essentially > treating all the data as though it came from a single session. The > issue is that when I do this, the GLM analysis takes prohibitively > long (with just 8 subjects, the analysis has already been running for > two weeks). To speed things up, I had the idea of doing the runwise > GLM (getting the betas and contrast values for each run), then > combining the runwise results to get t-values and p-values for the > whole session. However, I am not entirely sure how to do this last > bit; is there some kind of function that can be used to take all the > per-run t-values or effect sizes in a session and combine them to get > an aggregate t-value and p-value for the whole session, for a given > contrast? I believe FSL follows this analysis strategy (doing runwise > analyses then combining them into the whole session), so I was > wondering whether FSFAST had a way of doing the same. > > Thank you very much, > > JohnMark > > > _______________________________________________ > 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.
