Hi Afni experts,
I have a meaningful interaction involving two groups for a contrast of Song type A > Song type B. Due to an unforeseeable difference between my two groups on a variable related to Song type B only, I've included that variable as a covariate in this analysis. I would like to now plot the betas for this interaction including the lower order components (song type A > baseline and song type B > baseline for each group separately) to better understand the interaction but I wanted to ask what would be the most appropriate way to handle the covariate related to Song type B? Regress it out of the betaweights for all of the song types >baseline conditions (collapsed across groups)? Only the Song type B > baseline conditions (since the covariate only applies to this condition) collapsed across groups?
The covariate is mean centered across groups. Thanks for any direction with this situation! (Is there a better way to handle this within AFNI instead of off-line?)

Cheers,
LGD