If most things in design haven't been proved conclusively, that would just mean that design as a field doesn't take research seriously and doesn't insist on a s

If most things in design haven't been proved conclusively, that would just mean that design as a field doesn't take research seriously and doesn't insist on a strong empirical basis. You don't need to wait for unspecified advances in neuroimaging. The basic research can be done 50 years ago. You measure the mind with behavior, end of story. That part is as easy as A/B testing. Just do it. If you go to neuroimaging, you should first know why it is relevant and worth spending the $$$. And your feeling that the factors you suppose to be important are too many shouldn't ever stop us from looking into it. When we really get down to brass tacks on a subject, it's common to find that a lot of the factors we suppose to be important contribute negligibly to the final outcome. You just don't know which these are until you look.