Dear SPMers,
I would like to ask how to call out images for masking in the contrast
manager at the second-level analysis (a random-effect model) in SPM99.
I conducted an experiment that contained two task-conditions, task A and
task B, in one fMRI session. I made "con*.img" files of 4 contrasts,
namely, A (1 0), B (0 1), A > B (1 -1), and A < B (-1 1), for each
participants (n = 12). Then, I performed a one sample t-test of "Basic
models" for each contrast. I found inexplicable activation in A > B
statistics, that is, activation foci that were not observed during the
A-only statistics. Thus, I suppose I have to mask the inexplicable foci
appropriately.
My idea is that I have to mask the results of "A > B" by the results of
"A", using the "exclusive" option of "nature of mask". However, I could
not call out the images other than the contrast for "A > B" and an "all
effects" at the contrast manager of "A > B" statistics.
Would you show me how to call out the A-only contrast image in the
contrast manager?
Or, is my idea wrong?
Sincerely,
Kayako Matsuo
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Kayako MATSUO [log in to unmask]
Electrotechnical Laboratories, Medical Vision Lab.
OSL Unit, AIST
1-8-31 Midorigaoka, Ikeda, Osaka, 563-8577 Japan
tel) +81-727-51-8424 ext.9831
fax) +81-727-51-8387
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