Hello,
I would appreciate any help on the following question as I have looked through all of the example designs and am still not certain:
I am analyzing an inherited dataset and the task is as follows: There are two groups of participants (1 and 2), who have two separate sessions (A and B) while in the scanner. To compare between groups, the contrasts need to consist of the difference in activation between session A and B (A > B and A < B). I am not concerned with whether the groups differ between sessions, but need the neural activation differences between sessions as my dependent variable. Therefore, I am not interested in running an ANOVA.
The only way I could think of doing this is to perform a paired t-test separately on each individual, and then use the resulting .feat to compare between the two groups. This way, I get the difference between sessions to utilize in a between groups t-test. Does this work? If this is correct, how would I set-up the individual paired t-test? I made a .feat for each session (A and B) and thought I would go to Higher-level analysis, fixed effects, and input the two sessions. For the stats though I am unsure. I was thinking that for the "EVs" tab: I would have one main EV, and would change "EV1" to "1" for "Input 1" and "-1" for "Input 2"? Does this make sense? How should I make the opposite contrast (A < B)?
I would really appreciate any help as I am new to FSL.
Thank you in advance.
Ryan Bell
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