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Date: Thu, 1 Dec 2011 14:31:27 -0500
Subject: Re: [SPM] fmri design
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It depends on your question:
(1) Are the groups different: two-sample t-test of condition1, two-sample t-test of condition2, two-sample t-test of the mean of condition1 and condition2

(2) Are the conditions different and/or is the difference between conditions different between groups: flexible factorial design with subject, group, condition factors and subject, group, condition, and group*condition effects modelled. You cannot compare the groups (between-subject effects) in this model because of the error term generated for this model, but you can compare conditions and group*condition (within-subject effects) using this model.

There are a number of posts on the issues of mixed designs.

Best Regards, Donald McLaren
=================
D.G. McLaren, Ph.D.
Postdoctoral Research Fellow, GRECC, Bedford VA
Research Fellow, Department of Neurology, Massachusetts General Hospital and
Harvard Medical School
Office: (773) 406-2464
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