We assume brains work in the same way, but we lack any kind of tooling for examining this other than fMRI. All this high level stuff like conceptualisation and visualisation relies on subjective self-reporting. I don't think we've even proved whether or not Chomsky's "universal grammar" hypothesis is correct.
>We assume brains work in the same way, but we lack any kind of tooling for examining this other than fMRI
Yes, but it's also kind of a no-brainer. We're the same species, with mostly the same wiring...
Yes, but these study outliers. Most everybody's brain works the same way (or in a few, finite, ways)