Hey all,
I am still pretty new to SPM, but I couldn't find the answer to
this one, and the folks I'm working with weren't sure. Please let me know
if I missed something obvious!
I am using SPM99, I also have wfu_pickatlas and marsbar installed.
I have a study with four conditions including baseline, and we are
interested in knowing which areas are activated in all cases realtive to
the baseline. So something like this:
(C4>C1) /\ (C3>C1) /\ (C2>C1)
where /\ is intersection.
(actually, we are interested in confirming that a particular region is
activated in all these regions, so we are restricting our analysis to a
particular ROI, in case it matters).
It seems the right way to do this is to select the three contrasts (which
represent C4>C1, C3>C1 and C2>C1) in the results section. Assuming this is
right, I am not sure what to say in response to spm's question "Null
Hypothesis to assess". The options are "Conj'n," "Intermediate," or
"Global". Will "Global" give me the intersection of these contrasts? Am I
way off base? Also, does the orthog. order really matter? Thanks in
advance!!!
bjorn
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