I don't know what "two samples" refers to. doug
Asaf Kaftory wrote: > Hey Doug - first of all, thanks for the reply. second - > > 1. I'm afraid i didn't get the explanation. what is the FIR, and what > does it mean "two samples in the FIR" ? > > 2. ok, thanks. isn't it strange though? how do researches jitter the > ISI than? manually? > > 3. thanks. > *From:* Doug Greve <gr...@nmr.mgh.harvard.edu> > *To:* Asaf Kaftory <asaf_kaft...@yahoo.com> > *Cc:* freesurfer@nmr.mgh.harvard.edu > *Sent:* Saturday, September 26, 2009 7:42:43 PM > *Subject:* Re: [Freesurfer] optseq2 help: DPSD and jitter > > > On Sat, 26 Sep 2009, Asaf Kaftory wrote: > > > Hello list, > > > > I'm new to optseq, and would like your help with the following issues: > > 1. What exactly does DPSD mean? and why does the TR has to be an > integer of it? > > Delta Post-Stimulus Delay. The time between samples in the > FIR. Usually, it is just the TR. If you want to do sub-TR estimation, > you can make it less than the TR. It has to be an integer divisor of > the TR because it forms the basic "tick" of the clock. > > > 2. My experiment design uses jitter - both ITI (i.e., between > > trials) and ISI (i.e., between stimulus within a compound event). As i > > understood, optseq can only supply me with the ITI jitter but no the > > ISI jitter. is that right? do you happen to know a computerized method > > to introduce a jitter within a compound event? > > That is right. Sorry, don't know of anything that will give you > with-in event jitter. > > > 3. Is it true that jitter in optseq is made by inserting "NULLS", > > and that the DPSD determines the "steps" of the jitter (for e.g., if > > DPSD equals 1, Nullmin equals 2 and Nullmax equals 4, the NULL events > > will be 2 3 or 4). Did i understand it right? > > Yes. > > doug > > > > > hope to hear from you soon, > > Asaf. > > > > > > > > -- > Douglas N. Greve, Ph.D. > MGH-NMR Center > gr...@nmr.mgh.harvard.edu <mailto:gr...@nmr.mgh.harvard.edu> > Phone Number: 617-724-2358 > Fax: 617-726-7422 > > In order to help us help you, please follow the steps in: > surfer.nmr.mgh.harvard.edu/fswiki/BugReporting > <http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting> > > > > ------------------------------------------------------------------------ > > _______________________________________________ > 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 In order to help us help you, please follow the steps in: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
