The FIR assumes that your stimuli will be presented on a "clock", eg, on a TR (not necessarily ever TR, but every time a stimulus is presented, it starts on a TR). The "tick" of the clock can be the TR or it can be an integer divisor of the TR (eg, TR/2 TR/3). The finer you make it, the more flexibility you have as to when a stimulus can occur. But you loose power based on the divisor, eg, TR/3 means that you'll have 1/3 the power.
On 9/10/19 11:35 AM, Nasiriavanaki, Zahra wrote: > Hi Doug > > Thank you very much for your reply. How does it make a difference if I > use FIR? Could you please explain a little bit more? > > Thanks > Mona > > *Zahra (Mona) Nasiriavanaki* > > Postdoctoral Research Fellow > > Martinos Center for Biomedical Imaging > > Massachusetts General Hospital > > 149 13th Street, 149-2615 > > Charlestown, MA, USA, 02129 > > > > ------------------------------------------------------------------------ > *From:* freesurfer-boun...@nmr.mgh.harvard.edu > <freesurfer-boun...@nmr.mgh.harvard.edu> on behalf of Greve, Douglas > N.,Ph.D. <dgr...@mgh.harvard.edu> > *Sent:* Tuesday, September 10, 2019 11:24 AM > *To:* freesurfer@nmr.mgh.harvard.edu <freesurfer@nmr.mgh.harvard.edu> > *Subject:* Re: [Freesurfer] Opseq2 question > If you are going to assume a shape to the hemodynamic response, then I > don't think it makes much difference. It will make a difference if you > are going to use an FIR. > > On 9/9/19 10:49 AM, Nasiriavanaki, Zahra wrote: > > Hi Freesurfer experts > > > > I have a question about designing an event related task. We are > > designing a task for fear conditioning. Each stimuli presentation > > lasts 4 seconds. My question is if we set the TR to 2 (which is a > > multiply of 4), will it make the paradigm to have more power in signal > > detection? Or does it not matter if the TR and stimuli presentation be > > a multiply of each other or not? > > I appreciate if you give me your comments on that. > > > > Thanks a lot > > Mona > > > > *Zahra (Mona) Nasiriavanaki* > > > > Postdoctoral Research Fellow > > > > Martinos Center for Biomedical Imaging > > > > Massachusetts General Hospital > > > > 149 13th Street, 149-2615 > > > > Charlestown, MA, USA, 02129 > > > > > > > > > > _______________________________________________ > > Freesurfer mailing list > > Freesurfer@nmr.mgh.harvard.edu > > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
