Hi all,
Thanks a lot for the feedbacks. Now I have more ideas...
But I'm still not quite sure that should I use '0' or the the Reaction Times
for my trials' durations (in SPM2).
I've also read the recent discussions on "FIR models and PSTH values" and
learned something from those, but I'm still not sure what's the rule to
dicide
which one to use? Is there a objective way to decide it? Or should I try
both and used the one I like? (sounds like cheating...?)
PS: My TR=2s, RTs may range from about 700 ms to even longer than 2s (up to
4s).
but the Means might be around 1 to 1.5 sec.
And different conditions may have different mean RTs (does this matter?)
Thank you very much for any suggestions,
Chun-Yu
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Chun-Yu Lin, Graduate Student
Cognition & Neuroimaging Laboratories
Department of Psychology
University of Arizona
Tucson, AZ 85721-0068
http://www.u.arizona.edu/~cylin/
email: [log in to unmask]
> > I have a er-fMRI experiment on repetition priming. 27 slices (for Spiral
> > functional
> > and T1 images), voxel size: 3.5 x 3.5 x 4mm, TR=2s,
> > 3 sessions each has 450 scans (repetitions). I also have SPGR images.
> > 3. Should I use '0' (event) for Durations or the RTs of each trial?
> > Since mine is an priming experiment, the RTs of target conditions
> > are usually longer the the RTs of prime conditions. Will this
> > systematical
> > difference effect the model estimation?
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