Dear All,
I am studying the correlations between some brain regions. In order to do so, I am looking at the
actual activation values in each region (for each subject) and then computing correlations between
those values.
I defined several contrasts and performed some additions with those contrasts. So, let's say I have
the following contrasts:
A = [1 0 0 0]
B = [0 1 0 0]
C = A+B
So, C = [1 1 0 0]
My question is the following: How is this "addition" of contrasts translated in terms of activation
values? In other words: For contrast A, I observe value "a" in a given voxel (or ROI), for contrast B, I
observe value "b", and for contrast C, I observe value "c". What is the mathematical relation
between these 3 values? That is, what is the function f such that f(a,b)=c ?
Thanks so much in advance for your help,
Susana
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