makuuchi michiru wrote:
> I am hoping to find a conjunctional activation in an experiment
> which has three conditions: A, B, and C.
> My concern is that the conjuncional activation of (A-C) & (B-C)
> can be obtained, since the two contrasts were not orthogonal.
> In SPM96, this combination was accepted, but not in SPM99.
> I would like to know whether it is completely wrong or nonsense
> to perform this analysis in SPM96.
Dear Makuuchi,
Here's another suggestion re. your conjunctions query.
If you have enough events in condition C then, by splitting C
into two subsets C' and C'',
the contrasts for (A-C') and (B-C'') will be orthogonal.
Yours,
Will.
--
William D. Penny
Wellcome Department of Cognitive Neurology
University College London
12 Queen Square
London WC1N 3BG
Tel: 020 7833 7478
FAX: 020 7813 1420
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URL: http://www.fil.ion.ucl.ac.uk/welcome.html
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