Leading Neuroscientist Says Kurzweil Singularity Prediction A “Bunch Of Hot Air”

What you're saying is merely postulation, it's not "demonstrably" true, not to mention your use of the term "impractical" is probably the most misleading use of that word I've read today.

You're writing off thousands of years of philosophy and dozens of years of experimental results in maybe a paragraph, if I'm being generous.

The whole question of whether everything in the universe is computable is usually regarded as an open question, sometimes called the Church-Turing-Deutsch thesis. This wikipedia article has a little more: http://en.wikipedia.org/wiki/Church%E2%80%93Turing%E2%80%93D...

Lots of possibilities allowed by general relativity (e.g. computers orbiting black holes and information traveling backwards through time) that may or may not correspond to our universe allow for computation beyond that of a Turing machine. Until we understand quantum gravity it seems premature to write off those possibilities.

Even simpler, there is the question of whether the universe allows for arbitrary precision measurement of a physical quantity. If it does, then it may turn out that an observable physical quantity (e.g. the mass or charge of a fundamental particle) is a noncomputable real number. If it doesn't, then it may be possible to represent a neural network with noncomputable real weights, but impossible to actually measure them to enough accuracy to simulate the network on a given input.

Technically, you'd have to say that brain's output is combination of computable system and a perfect random noise source.

That is because a simple source of quantum noise should not be computable. Any computable pseudo-random noise generator produces strings of digit with asymptotically constant Kolmagorov complexity while the Kolmagorov complexity of a true random number generator goes to infinity.

All that said, the person is article is certainly overreaching to imply we can know the brain definitely isn't computable. Clearly he does have any kind of knowledge that would tell him that. This might enough to say since the rest of his argument seems to hinge on this.

You're being overly tight with your definition. We still don't completely know how the brain works, and while we have a top-down discipline and a bottom-up discipline, we still haven't figured out how they meet in the middle - and the fundamental point he's making is that there's nothing to say that we will get those algorithms. Until we get to that stage, regardless of whether it's theoretically feasible if you had a magic emulation tool, it's not feasible because we don't have the algorithms to emulate. And if we get to that stage, 'we made a brain emulator!' is one of the smaller stories, since things like 'we have answered the questions of whether free will and the soul exist' will be far more profound.

>Yes, you can. It will be impossibly huge and slow, but you can.

A major problem is many of the brain's processes use "chaotic models". These are what we associate with the "butterfly effect" where extremely tiny deviations from the true value make the model diverge from actual behavior. Most models tend to have some tiny deviation from the true value but it usually doesn't matter. In this case it does, and it may be an insurmountable problem.

The brain might be computable but that doesn't mean a classic turing machine would work. Maybe one day we can build a biological protein-based computer that shares the "irreducible properties" of brains, but then all we've really built is a brain.

I'm just wondering, how does this statement make sense if we replace the "brain" with "a block of wood" since they are both a "quantum system, just like everything else in the universe":

"The part of the article that bothers me here the most is a leading lumberjack asserting that a block of wood is not computable. That is demonstrably false: a block of wood is a quantum system, just like everything else in the universe. All quantum systems containing n qubits can be simulated by 2^n classical bits. It may very well be impractical to compute a decent sized block of wood, but that's still technically computable."

What would it mean to say that a block of wood is computable?

Thank you for summing that up so concisely. I'm going to try to remember the "so you think human nature is something more than physics?" argument for the future.

There's nothing new about that belief.

That has always been my response to John Searle's Chinese Room [1] thought experiment. The argument boils down to the human consciousness either being magic or not. Magic being something beyond physics.

1: http://en.wikipedia.org/wiki/Chinese_room

He doesn't suggest that human nature is more than physics, he is saying that consciousness isn't computable. If neural subsystems are a hierarchically arranged and internally generated chaotic dynamic activity, there is the problem of long-term predictions and causal inference.

>It may seem paradoxical that a deterministic phenomenon is inherently unpredictable, but in systems that exhibit chaotic behavior, small uncertainties are amplified over time by the nonlinear interaction of a few elements. The upshot is that behavior that is predictable in the short run becomes intrinsically unpredictable in the long term. As a result, physiologists cannot make strict causal inferences from the level of individual neurons to that of neural mass actions, nor from the level of receptor activity to internal dynamics. The causal connection between past and future is cut.

http://sulcus.berkeley.edu/freemanwww/manuscripts/IC13/90.ht...

I believe the argument is consciousness is not a causal product of relations represented in the brains structures but a property of the substrate.

Consider that a brain model on a turing machine is equivalent to a sticks and stones model running the same program. Do you believe some person moving a bunch of sticks and stones around can produce conscious experience?

God means different things to different people, from one that watches everything you do, to one that maybe is a force out there, like gravity.

I keep asking Siri "Can entropy be reversed?" hoping she'll respond with that. And Google hoping it'll show just that answer, no links. Wolfram get's it.

It is possible that the easiest way to simulate the brain in a way indistinguishable from an actual brain isn't to have something work in the same way.

There is nothing to say that evolution has arrived at the perfect method.

Small nit: Watson, not Deep Blue.

The "singularity" is never going to happen because it assumes intelegence is a single thing that can be increased with more processing power and better algorithms. Completely ignoring things like information theory, over fitting, insanity, training data, and chaos theory.

We can and probably will build reasonably general AI, but you far more likely to see each generation of AI being an ever smaller improvement than any sort of runaway exponential progression. Not to mention hardware progress has slowed to a relative standstill.

That's not really true about Newton by the way. Newton most likely believed he did not have a convincing argument he wanted to put his name to or advance that wouldn't also drag him into yet another round of having to deal with someone like Robert Hooke. At that point of his life, his ambition was greatly lessened and his success somewhat assured.

There is firm evidence he had at least 3 serious views (and one fairly archaic one not many want to talk about) on the cause of physical gravitation. It is only the "modernists" who need for Newton be be not beholden to any of them that elevate and reiterate "Hypotheses non fingo" to some sort of rallying cry as if he had it tattooed on his torso.

Singularity does not have to do with our perception of the intelligence of a machine. In singularity the importance/validity of that machine's perception of our intelligence is higher than our's. Therefore, I wonder whether we will be able to know it when we reach singularity.

Kurzweil is saying much more. In The Age of Spiritual Machines he states "Artificial Intelligences claim to be conscious and openly petition for recognition of the fact. Most people admit and accept this new truth." What cluster of running software by which algorithms produces this consciousness 16 years from now?

I'd wager against that incremental model.

I'd say that strong artificial intelligence is far more likely to happen via bottom-up modeling of the existing human brain as a starting point. The computational capacity for reductionist simulations that will exist probably 20 years from now, and as computational capacity increases those simulations start to become emulations. I don't expect to see massive gains over that time in the other way of doing it.

Once you have crude human brain models, a lot of very unethical things will start to happen in the course of further development. (e.g. countless deaths of intelligent beings if you're in the continuity identity boat, and probably a lot of unavoidable pain and suffering regardless of your take on identity). That seems hard to prevent given the enormous advantages that will accrue as a result; there is a strong incentive for people to adopt the pattern identity point of view so as to justify what they are going to do with mind copies in the course of development.

The important point is that once you have human brain models, from there the path to many different forms of strong artificial intelligence is just a matter of iterating those models. This seems far more likely to produce results than constructing new forms of intelligence progressively and de novo.

Deep Blue's Jeopardy performance was in large part due to its buzzer speed. It also managed to answer questions correctly, but game mechanics also played a role. http://ken-jennings.com/blog/archives/2554

That would take a seriously powerful computer.

I remember reading a short story along those lines.. it ended with the simulated beings hacking physics and dropping off into a pocket universe, without helping at all.

Well, I guess they didn't kill us all. Might have been written by Greg Egan. Sounds familiar?

> Personally, I'd say Paul Allen's counter-argument, which I recall as boiling down to the inherent limits of human-produced software, is the most plausible counter-argument

I often wonder if the ultimate end counter argument may be that the same things that make us "intelligent" are also those that give us our human flaws - exactly the same things that we were trying to avoid in the first place by using computers. Perhaps we can't have human-like intelligence without also being forgetful, inaccurate, selfish, lazy, irrational, greedy, angry, sad etc. If someone did invent a computer with all those attributes, would it be useful?

Ramanujan isn't different than you or I in that regard. His brain was an assembly of neurons, connected via synapses. There's nothing pointing towards the fact that this assembly is any different from any machine, regardless of achievements in the field of mathematics. Because we fail to understand it fully yet doesn't mean it transcends physics, that would be absurd.