Hi all -
Can anyone point me toward a good explanation as to why FSL recommends setting the "minimum" and not the "mean" of component EVs to zero when setting up an interaction in FSL (or creating the interaction term manually, for that matter)?
Relatedly, is it sensible to interpret main effects (i.e. the effects of those component EVs), when an interaction effect is present - which would generally be interpretation of a standard regression result, if the main effect occurs in a) the same region as the effect of the interaction and b) a different region?
Cheers and all the best,