Yes, assuming a shape will give you much more power, at least for the individual subject. doug
On 04/11/2013 02:55 AM, SHAHIN NASR wrote: > > Sorry that I keep on asking questions but I want to know if using a > model can significantly increase the chance of getting a significant > response. > As far as I see for the positive peak, when I use a model (e.g. > gamma model or spmhrf), I see a more significant response compared to > when I use the FIR model. Is it correct? If true, then the same might > be correct for the negative peak. > > P.S.: To be more clear, I am talking about the response maps relative > to the baseline. > > On Apr 10, 2013 6:46 PM, "Douglas N Greve" <gr...@nmr.mgh.harvard.edu > <mailto:gr...@nmr.mgh.harvard.edu>> wrote: > > > yes, that is what you want. The only other way that comes to mind > is to model each event type as two event types one delayed > relative to the other. Then model the responseto each as a gamma. > If the delay is right, then the first gamma should model the main > positive response and the second gamma will model the negative > response. both will be independent from the other. > > doug > > On 04/10/2013 05:00 PM, sha...@nmr.mgh.harvard.edu > <mailto:sha...@nmr.mgh.harvard.edu> wrote: > > I think I figured it out but I want to double check. I am > generating > group-average map for my subjects using isxconcat-sess command > which > generates ces maps for each time frame. I think these maps are > what I > wanted. Right? > If you still have other solutions that you think may > generate more > reliable results, I am eager to know. For instance, is there > anyway to > fit a model as we do for spmhrf or fslhrf, but just for the > negative > peak? > > Regards > > That's the problem Doug. I have already generated the FIR > model but how > can > I show the sig MAP for one "particulat time point". What > are the other > ways? > > > On Wed, Apr 10, 2013 at 4:05 PM, Douglas N Greve > <gr...@nmr.mgh.harvard.edu > <mailto:gr...@nmr.mgh.harvard.edu>>wrote: > > Hi Shahin, there are several ways that you could do > it. The one that > immediately comes to mind is to use an FIR and then > test for a > difference > at a particular post stimulus time point. > doug > > > > > On 04/10/2013 03:54 PM, SHAHIN NASR wrote: > > Hi, > I want to generate a map to show the > significant difference > between > HRF undershoot (negative peak of activity) > between two conditions > independent from the positive peak. Is there > anyway, to generate this > map? > > P.S.: Please note that I need a map and not a time > course graph. > > > -- > Shahin Nasr > > PhD in Cognitive Neuroscience > Martinos Imaging Center, MGH > Harvard Medical School > > -- > Douglas N. Greve, Ph.D. > MGH-NMR Center > gr...@nmr.mgh.harvard.edu > <mailto:gr...@nmr.mgh.harvard.edu> > Phone Number: 617-724-2358 <tel:617-724-2358> > Fax: 617-726-7422 <tel:617-726-7422> > > Bugs: > surfer.nmr.mgh.harvard.edu/**fswiki/BugReporting > > <http://surfer.nmr.mgh.harvard.edu/**fswiki/BugReporting><http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting> > FileDrop: > www.nmr.mgh.harvard.edu/**facility/filedrop/index.html > > <http://www.nmr.mgh.harvard.edu/**facility/filedrop/index.html><http://www.nmr.mgh.harvard.edu/facility/filedrop/index.html> > Outgoing: > ftp://surfer.nmr.mgh.harvard.**edu/transfer/outgoing/flat/** > greve/ > > <ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/> > > > > > -- > Shahin Nasr > > PhD in Cognitive Neuroscience > Martinos Imaging Center, MGH > Harvard Medical School > > > > -- > Shahin Nasr > > PhD in Cognitive Neuroscience > Martinos Imaging Center, MGH > Harvard Medical School > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > <mailto: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 <mailto:gr...@nmr.mgh.harvard.edu> > Phone Number: 617-724-2358 <tel:617-724-2358> > Fax: 617-726-7422 <tel:617-726-7422> > > Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting > <http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting> > FileDrop: www.nmr.mgh.harvard.edu/facility/filedrop/index.html > <http://www.nmr.mgh.harvard.edu/facility/filedrop/index.html> > Outgoing: > ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ > > -- 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.
