I have two groups, cocaine and control. I did the first level, generated
contrast images, and used the contrast images for designing 2nd level
two-sample t-test.
I've attached the 2nd level design. (Group 1 are the cocaine subjects) After
estimation, I used for contrast,
[1 0] for Cocaine > Control, and
[0 1] for Control > Cocaine.
Both t-tests.
Did I do this correctly? The problem is, after I overlay using render, I get
activation in the same regions for both Cocaine > Control and Control >
Cocaine maps. What's more, the comparison maps seem much brighter than the
individual maps, which seems very odd. I am attaching four different files.
CCtDiff Sem.jpg : Cocaine > Control (2-sample t-test)
CtCDiff Sem.jpg : Control > Cocaine (2-sample t-test)
Cocaine Sem.jpg : Cocaine (1-sample t-test)
Control Sem.jpg : Control (1-sample t-test)
Am I interpreting the results correctly? Why am I getting activation in the
same areas for both Control > Cocaine and Cocaine > Control? What am I doing
wrong?
I appreciate any input. Thank you.
- Ananth
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