Whoops, I just saw your response in your response. My bad -- please ignore.
Alex On Fri, Jan 25, 2013 at 10:37 AM, Alex Kell <alexk...@mit.edu> wrote: > Hi Doug, > > Thanks for the information about how FS whitens the data. Is there a way > to temporally whiten data without running a GLM (i.e., without running > selxavg3-sess)? > > > Alex > > > > On Tue, Jan 22, 2013 at 9:58 AM, Douglas N Greve < > gr...@nmr.mgh.harvard.edu> wrote: > >> >> On 01/19/2013 03:18 PM, Alex Kell wrote: >> > Hi Freesurfers, >> > >> > I have two unrelated questions. >> > >> > 1. I want to pre-whiten some functional data without running a GLM on >> > them (we're going to run the GLM in matlab). It looks like fsfast >> > does autocorrelation correction as a part of the selxavg3-sess >> > wrapper. I tried poking around on the wiki and mailing archives, but >> > I can't find how to pre-whiten the data without running a GLM. Is >> > there a straightforward way? If not, I guess we could just do it in >> > matlab. >> FSFAST uses an AR1 model. It computes the AR1 from the residuals (thus >> needing to run the GLM first). The voxel-wise AR1 is spatially smoothed, >> then binned into 10 bins. All the voxels in each bin are then analyzed >> in the same way. >> >> > >> > 2. Separately, we're bringing some volume masks to the surface and are >> > preprocessing them with dilation and erosion to clean them up. We're >> > trying to get a sense of how much is a reasonable amount to dilate and >> > erode by, and it would be helpful to know about how far apart the >> > adjacent surface vertices are. Roughly, what's the mean distance >> > between adjacent vertices? >> About 1mm >> doug >> > >> > Thanks in advance. >> > >> > >> > Best, >> > Alex >> > >> > >> > >> > >> > _______________________________________________ >> > 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: 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. >> >> >
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