Hi SPMers,
I am a new user of SPM5.
In my experiment, 14 subjects received 2 fMRI scannings
(low-temperature vs. high-temperature stimulus, 10 stimuli per scan,
10 seconds per stimulus), 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 t maps (high temperature vs. low temperature) were established
(2).The contrast was 1 -1.
(3).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§1 0ˇ¨.
Can I inclusively mask ˇ§(high temperature) minus (low temperature)ˇ¨
with ˇ§(high temperature)ˇ¨ in the paired t-test analysis in SPM5?
I'd appreciate for any help.
Thanks
Dr. Tseng
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