Mike,
You could also use a regression model with main effects for diagnosis
and treatment and include an interaction term for diagnosis X
treatment effects since these are likely of particular interest in
your study. As an example, we used this approach in our donepezil
study (Brain 2004; 127:1574-83).
Andy Saykin
At 10:23 AM 7/27/2005, Mike Angstadt wrote:
>Hi,
> We're looking for the best way to analyze a design like the
> following:
> - Two groups of subjects (ex: patients and controls)
> - two levels of treatment (ex: drug and placebo)
> Each subject has 2 scans from separate days. One for the
> drug condition and one for placebo. What's the easiest and/or best
> way to look at the group RFX?
> One idea we had was to just model both scans in one large
> design matrix (as in this post
> http://www.jiscmail.ac.uk/cgi-bin/wa.exe?A2=ind0502&L=SPM&D=0&I=-3&X=334B9904DDB400BF3B&Y=&P=15311)
> But we weren't sure if that was the best way.
> Since SPM2 doesn't offer a 2-way ANOVA, what's the best
> option to run something like that? Is there a script someone has
> to make SPM2 do a 2-way? Or could I fake it with a one-way ANOVA
> with 4 conditions (ex: patient_drug, patient_placebo, control_drug,
> control_placebo)?
>
> Thanks
>
>-Mike
========================================================
Andrew J. Saykin, PsyD, ABPP
Professor of Psychiatry and Radiology
Director, Neuropsychology Program and Brain Imaging Laboratory
Department of Psychiatry - DHMC
Dartmouth Medical School
Lebanon, NH 03756
Tel. (603) 650-5824
Fax (603) 650-5842
email:[log in to unmask]
http://synapse.hitchcock.org
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