Hi,
I run a simple fMRI experiment with 3 conditions A/B/C, whereas B and C are usually followed by a response. If I want to compare condition A to B and C, how do I set up my contrast? Is it 2 -1 -1 or is it 1 -1 -1?
(The number of conditions for A is a bit higher than for each single condition B or C)
Moreover, do I also have to model the response phases after B and C in my design matrix? One researcher on a conference said that I need to define ALL my conditions, and another one said that I need to have unmodeled events, that SPM can compute a baseline.
What is the best way (and why)?
Thanks so much for your help,
Melea
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