Dear Cathy,
As far as I know, there is no difference if you process data separately for each subject until smoothing stage. In my opinion, the only advantage to do all subjects at once is that you are completely sure to apply the same parameters to all, especially if you are absentminded like me ...
Philippe
At 17:59 15/10/99 -0600, you wrote:
>Hi,
>
>I want to run analyses on fMRI data for 7 subjects
>with 6 runs each. I have some questions regarding
>how SPM99b works in the realignment, coregistration and
>normalization processes.
>
>Is there a difference in the calculations if I run the
>various preprocessing programs separately for each
>subject and then combine them in the statistical
>analysis versus specifying 7 subjects with 6 runs in
>the realignment etc processes? In other words, does it
>change anything to do the realignment, coregister, normalization and smoothing
>processes once for each subject versus realigning etc for
>all 7 subjects at once?
>
>Many thanks in advance, Cathy
>
>-------------------------
>Catherine L. Reed, Ph.D.
>Assistant Professor of Psychology
>University of Denver
>2155 S. Race St. Denver, CO 80208
>Phone: 303-871-4622 FAX: 303-871-4747
>E-Mail: [log in to unmask] (attachments)
> [log in to unmask] (messages)
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PEIGNEUX Philippe, Lic. Psych., Chercheur
E-mail: [log in to unmask]
Cyclotron Research Centre
Neurology Unit & Neuropsychology Department
Liege University BELGIUM
http://www.ulg.ac.be/neuropsy/
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