[SomeoneFromCA]

Not a quantum physicists, but IMO Bekenstein bound is not applicable here, because quantum laws are non-deterministic, therefore you can describe the structure of a system, but you cannot describe how it will evolve. Quantum randomness might be in the very essence of how the brain and mind works.

[catalogia]

Quantum randomness being necessary hardly seems like it would have profound practical implications since augmenting a digital computer with a geiger counter would be trivial.

[criddell]

It's much easier than that. Hardware random number generators are often based on something like a reverse-biased diode. Electrons migrate across and it's entirely random when it happens. Amplify and count them and you get a great source of entropy.