I am trying to define contrasts for the first stage of a RanFx analysis of
SPECT data-- two conditions per subject, one scan per condition. I have 75
subjects, distributed across treatment conditions. I would like to examine
the groupXcondition interactions in an appropriate way.
I enter these data into the "Multi-Subject: subj X condition interaction &
covariates" model-- planning to ignore the condition effect until the
second level. However, I can't get past the first level: with this model, I
consistently get a GUI error.
Is this a software problem on my system, or a design problem?
I am concerned that this model would produce as many columns as scans, and
so be inestimable or "over-determined"?
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Christopher Gottschalk, MD *
Assistant Professor of Neurology & Psychiatry *
Yale School of Medicine *
*
Mailing Adress: *
VAMC [116-A] tel [203] 932-5711 x4329*
950 Campbell Avenue FAX 937-4791*
West Haven, CT 06516 *
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