Dear Christy,
> We were interested in answering the question, "what areas are active in
> condition B which are not active in condition A?".
Unfortunately you cannot make a (valid) statistical inference about an
effect not being present ('not active in condition A'); only something about
the alternate hypothesis. So you cannot formally answer this question,
although exclusive masking in SPM allows you to create SPMs that address it
anecdotally.
best wishes,
Geraint
--
Dr. Geraint Rees
Wellcome Advanced Fellow, Lecturer,
Division of Biology 139-74, Institute of Neurology,
California Institute of Technology, University College London,
Pasadena CA 91125 London WC1N 3BG
voice 626-395-2880 020-7833-7472
fax 626-796-8876 020-7813-1420
web http://www.klab.caltech.edu/~geraint
--
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