Dear SPM users, I have a question relative to one of my contrasts at the first level. I have three condition A, B and C. I would like the see what is more active in condition A relative to (B-C). So I am interest to the contrast A>(B-C). Which one of these two solutions is correct ?
Solution 1(equal weight to all): Contrast=[1 -1 1]
Solution 2(scale the condition B and C relative to the condition A): Contrast=[1 -0.5 0.5] ?
It doesn’t matter that the addition of contrast’s coefficients is not equal to 0 ?
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