Hi Tom,
I was a little surprised when I found the results in the attached .ps file.
First I ran the comparison for negative effects with a cluster defining
threshold of t=2.6 (the results are shown on page 4 of the ps file), then I
remembered that I had used a smaller threshold earlier and I reran the
results with a threshold of t=2.54 (page 7 of the ps file). Two
non-overlapping areas of statistical significance emerged. It's not really
clear to me how this can happen. If there are enough contiguous voxels to
make a cluster emerge at the more stringent t-threshold, shouldn't these all
be present in the more lax threshold test?
Stefano Marenco, MD
GCAP, Clinical Brain Disorders Branch,
NIMH
10 Center Drive, room 4S235
Bethesda, MD 20892
tel. (301) 435-8964
fax. (301) 480-7795
email: [log in to unmask]
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