I am new to FSL and am creating my design matrix for Level 1 FEAT contrasts. I have a question about “unbalanced contrasts”.
For example, we have three trial types, let’s call them: Very Mean, Moderately Mean, and Nice
I want to have a contrast that looks like so (Very Mean + Moderately Mean) - Nice and call it All Mean - Nice
In FSL would that be: 1 1 -1
OR do I have to do: .5 .5 -1
I’m not sure if I’m able to have two +1’s and only one -1 or if I have to take the two +1s and make them +.5s instead, so that it is balanced with the -1.