Hi SPMers,
(Here I paste my question again for more clear description)
In my experiment, 14 subjects received 2 fMRI scannings (low-temperature vs.
high-temperature stimuli), and I want to investigate the difference in brain
activations for the 2 stimulus temperatures.
The contrast ˇ§(high temperature) minus (low temperature)ˇ¨ means that which
brain regions show significantly higher responses for the high-temperature
stimulus than those for the low-temperature stimulus.
I used paired t-test in SPM5 to perform this analysis. The procedures are as
follows:
(1).14 pairs of con*.img files (low temperature vs. high temperature) for each
subject were established
(2).The JPEG of the design matrix is attached
(3).The contrast was 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 1.
(4).Then I got the activation map
However, I want to get another map.....
The contrast ˇ§(high temperature) minus (low temperature), with the (high
temperature) as the inclusive maskˇ¨ means that which high temperature-
activated brain regions show significantly higher responses for the high-
temperature stimulus than those for the low-temperature stimulus
(Is my understanding correct?).
Again, I used paired t-test in SPM5 to perform this analysis. However, how
can I ˇ§maskˇ¨ the ˇ§(high temperature)ˇ¨? Because it seems not allowed to
establish the contrast ˇ§0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1ˇ¨.
Can I inclusively mask ˇ§(high temperature) minus (low temperature)ˇ¨
with ˇ§(high temperature)ˇ¨ in the paired t-test analysis in SPM5 2nd-level
analysis?
I'd appreciate for any help.
Thanks
Dr. Tseng
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