Hi AFNI experts,
I’m looking for the best way to look for a relationship between a certain continuous behavioral metric and beta image outputs of a GLM.
Each subject has 3 betas representing different parts of a task (difficulties), and each beta has an associated behavioral score. I expect these behavioral scores to differ a little between the three, but for now am only interested in the general effect of this score on activation. I will probably eventually want to know the effect of these 3 conditions as well, so I’m hesitant to average them.
I don’t necessarily expect that this relationship is linear, though it’s probably at least monotonic if not.
Is 3dMVM the best way to do this? I was going to just use a Spearman rank correlation, but am concerned that this may be wrong without accounting for having multiple measures per subject?