For one, you would have to determine whether physical laws are computational processes. Stephen Wolfram is trying this, but it requires some incredible assumptions.
The laws of physics we know right now are either computable or stochastic with computable probabilities. This was of course the only possible outcome if physics made any sense at all, since the purpose of physics is to compute outcomes, so a physical theory that was not computable would never have been invented.
Still, the laws of physics could be anything and it wouldn't matter for this question. The only relevant question is whether our brains are computers, regardless of how the physics work at the lowest level. After all, we have clear proof that you can make computers on the existing laws of physics (I'm typing this reply on one!), so all we need to know is whether our brains are bio-chemical computers. Neuroscience is nowhere near a level where it can answer this, but it at least remains a plausible explanation. After all, we humans can't compute any non-computable function, or at least none that we know of (the Church-Turing thesis).
