Comment by Zaphods | Hacker News Reader

Comment by Zaphods | Hacker News Reader

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> The brain can compute.

You'll see in my comment and your quote that I don't say the brain can't compute. I agree, the brain can compute. But that doesn't mean it is a computer, because computing is an ability. People can do many other things aside from computing, none of which rely on computation, for instance they can imagine, which is the ability to think new thoughts. Computers can't imagine because all they do is compute: that's their programming. No amount of programming can produce imagination. Computation and imagination are categorically distinct as different intellectual powers and abilities.

You are conflating an ability with ontology. We know what a brain is. It's a collection of fatty material with neurons that do not explicitly fire exactly like a computer. Key word there is like. Church-Turing built a model of computational logic off of intuitions about the brain and formal mathematical logic. That's it's not provable doesn't prove your point; it removes any distinction between it being right or wrong: because it is a model (lets make something like the brain).

That an industry was built on computation doesn't prove anything. We know computation is an ability. For instance it's also something we can do with abacuses. We could have built an enormous industry on building elaborate abacuses. We built computers do be extremely fast at computation. We didn't build computers to be brains.

You'll notice, if you read the review, that the author of the review repeatedly cites cognitive neuroscientists, even evangelists of the singularity, philosophers, psychologists, and zoologists, who have published at length on this topic and repeatedly critcise and disrupt the simple idea that the brain is a computer or an algorithm or even a machine. An entire branch of philosophy developed off of Ludwig Wittgenstein to counter the computational model of consciousness. Numerous books in the Philosophy of Mind argue that the assumption that the brain is a computer is not just unsupported, it is logically nonsensical.

"No amount of programming can produce imagination" is a very bold statement to make.

The brain exists in a physical universe, made out of matter/energy, and its behaviours are entirely dictated by the laws of physics; that's a fairly accepted truth unless you have solid evidence otherwise.

The laws of physics are mathematical and can be computed by their very nature, and we are already pretty good at simulating physical interactions to a quantum level, and this ability improves over time.

At some point in time, unless there is "magic" or missing physics, a sufficiently powerful computer with a physically accurate simulation of a brain would produce virtually identical results to a real brain.

So either there must be new physics involved, or, the notion that a sufficiently advanced computer simulation can't produce imagination must be abandoned.

A team of scientists able to sufficiently model the physics of the brain (and presumably the entire central nervous system, I imagine a disembodied brain simulation would experience a horrific form of locked-in syndrome) would not need to be concerned about emergent properties of the simulation such as a sense of consciousness, or thought, or imagination. Those things will just happen once the simulation is perfected.

Indeed the cognitive neuroscience folk, etc, would be invaluable to actually understanding, training, interpreting and caring for the brain simulation, and figuring out if its behaviours and interactions constitute consciousness etc, so I do not think this has to even be framed as programmers pretending to know about brain stuff vs brain people who dismiss any notion of computationally recreating consciousness. It would be a team effort that works both ways, but is already doomed to fail if half the team thinks it's impossible from the get-go.

It's not a remotely bold statement. Think about what imagination is, and then think about whether computers can imagine. Computers can't imagine. Computers can't come up with new things because they are programmed. Programming prescribes the outputs to the same limitations as the inputs: it's a closed deterministic system.

You'll see in my comment above this one that I agree that the brain is a physical thing. But abilities and powers are not physical. That's not voodoo magic. That's what abilities are. Think about horsepower. The horsepower of a car does not reside in any one physical thing, not the carburetor, or the intake manifold, or the piston, or the wheels; it's an ability of the car: it is able to go at such and such horsepower. That is what horsepower is.

The same applies to computation. Computing something is an ability, but we have many more intellectual and cognitive abilities beside computing things.

As a result

> a sufficiently powerful computer with a physically accurate simulation of a brain would produce virtually identical results to a real brain.

is just you are assuming that it will work, but nothing about computers supports that in the slightest. That's just a guess.

> A team of scientists able to sufficiently model the physics of the brain (and presumably the entire central nervous system, I imagine a disembodied brain simulation would experience a horrific form of locked-in syndrome) would not need to be concerned about emergent properties of the simulation such as a sense of consciousness, or thought, or imagination. Those things will just happen once the simulation is perfected.

All of this is still an assumption.

Again, that doesn't mean you are right or wrong: it means its an assumption. You have to accept the limitations of your assumption and the limitations of modelling the brain on a computer are large and glaring.

> Indeed the cognitive neuroscience folk, etc, would be invaluable to actually understanding, training, interpreting and caring for the brain simulation, and figuring out if its behaviours and interactions constitute consciousness etc, so I do not think this has to even be framed as programmers pretending to know about brain stuff vs brain people who dismiss any notion of computationally recreating consciousness. It would be a team effort that works both ways, but is already doomed to fail if half the team thinks it's impossible from the get-go.

You are assuming here that only the programmers are heading down the right path. But you don't know that. It's entirely reasonable (and I would say much more supportable) to say that the programmers are heading down the wrong path: their path will lead to nothing at all. That's because the programmers have fallen to a category error.

You think they need to model the brain on a computer for it to make sense. But there is actually very little if anything to support that.

Brains are brains. Computers are computers. That computer science can be fuzzily applied to the study of brains around the ability to compute does not mean the study of brains is computer science or that brains are computers.

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