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You can/should use the batch system and specify two sessions, since that's how the data were acquired. On 01/16/2013 01:52 PM, Joseph Dien wrote: > I would think you'd need to have separate sessions for the slice > timing too since slice timing depends on interpolating with the > adjoining volumes and if the conditions were not separated then the > last volume of the first condition would be interpolated with the > first volume of the second condition and vice versa. It would be > assuming that hemodynamic activity in the first volume of the second > condition represented a continuation of the hemodynamic activity from > the end of the first condition when in fact it would actually be > reflecting activity from during the break. > > Cheers! > > Joe > > > On Jan 16, 2013, at 9:28 AM, Ella <[log in to unmask] > <mailto:[log in to unmask]>> wrote: > >> Véronique, >> >> For the slice timing it doesn't matter, however for the realignment >> you should define two sessions within the same batch according to >> chapter 2 in SPM manual: >> >> " ... the sessions are fi rst realigned to each other, by aligning >> the fi rst scan from each session to the first scan of the first >> session. Then the images within each session are aligned to the >> first image of the session. The parameter estimation is performed >> this way because it is assumed (rightly or not) that there may be >> systematic di erences >> in the images between sessions." >> >> Best, >> Ella >> >> On Wed, Jan 16, 2013 at 11:53 AM, Ginsburg Veronique >> <[log in to unmask] <mailto:[log in to unmask]>> wrote: >> >> Dear SPM experts, >> >> I am a beginner with SPM and I have a question for the >> preprocessing step. >> My study was composed by two different conditions. >> The two conditions were run one after the other, so the >> participant didn't go out from the scanner between both conditions. >> After the first condition, before starting the second condition, >> we have stopped the scanner for giving some instructions and we >> restarted it to begin the second condition. >> I was wondering if I have to enter those two sessions (the first >> and the second conditions) during the realignment and the slice >> timing or if I have to create two different preprocessing (one >> for the first condition and one for the second condition) for >> each subjects? >> >> Thank you in advance for your response, >> Best, >> Véronique >> >> >> >> >> -- >> Ella Gabitov >> Ph.D student >> The E.J. Safra Brain Research Center for Learning Disabilities >> The Laboratory of Human Brain and Learning >> University of Haifa >> Israel >> Phone: +972-52-6722700 >> E-mail: [log in to unmask] <mailto:[log in to unmask]> > > > -------------------------------------------------------------------------------- > > Joseph Dien, > Senior Research Scientist > University of Maryland > > E-mail: [log in to unmask] <mailto:[log in to unmask]> > Phone: 301-226-8848 > Fax: 301-226-8811 > http://joedien.com// > > > > > > > > > > >