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Why Is the Human Brain So Efficient? (2018)

nautil.us

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Re: Why Is the Human Brain So Efficient? (2018)

#131

Post by jjoonathan »

ColanR wrote: post #111
jjoonathan wrote: post #105

Earlier quoted context omitted.

Less complicated systems successfully reason about more complicated systems all the time. Ditto for self-reasoning. See: bootloaders, update systems, and package managers. In order to prove that some kind of meta-cognition is inherently beyond our grasp, you don't just have to prove that the system we are attempting to reason about is more complex than ourselves, you also have to prove that the problem isn't meaningf…

I think you're describing an analogue of turing-completeness. It's not (to me) a question of whether we can reason about something: it's a question of how long it takes, and how much knowledge is involved with the process. What you're describing sounds like asking a PDP-11 to run GPT-3. Technically possible, in the broadest sense of the word. But a computer that can run GPT-3 successfully will look at that PDP-11 in…

On the contrary, I think your example proves my point quite well. I understand very little about PDP-11s and only slightly more about GPT-3's inner workings, yet I have no trouble reasoning about whether or not a PDP-11 is suitable for running GPT-3 or something even more difficult to formally reason about, say Microsoft Windows. I have a mental model of computer performance and compute requirements that simplifies the question from a difficulty of "Oh, it's Turing complete, halting problem, let's throw our arms in the air like this is an infomercial!" through "You need to understand literally everything about PDP-11s and Windows" all the way to "50 years of exponential growth is a hella large factor to try squeezing down anything by." It's a trivial question hiding in the skin of an intractable question, and it perfectly exemplifies why it's silly to believe that human cognition will forever remain intractable.

In order for a problem to forever remain in "let's throw our arms in the air like it's an infomercial" territory, it must not merely be difficult in its most pedantically defined complete form, it also must stymie the search for useful relaxations and workarounds. Nobody fears running a program on account of being unable to prove that it will halt: they just kill the program if it locks up, or (equivalently) set a timeout. Personally, I'd just avoid throwing my arms in the air like an infomercial altogether.

EDIT: substituted GPT3 -> Windows because arguments about GPT-3 and/or a set of incarnations being Turing Complete would be irrelevant to the main point.

Re: Why Is the Human Brain So Efficient? (2018)

#132

Post by TeMPOraL »

canjobear wrote: post #81
kristopolous wrote: post #69

They aren't the same thing. They are different classes of objects, different tasks. This comparison is kind of silly. I'd hate my computer to have the memory accuracy or the computational accuracy of my brain. I'd hate to have the creativity and inspiration of a computer. Delete being such a nontrivial operation is probably a good thing for humans. Copy being imperfect probably has something to do with the phenomenon…

When we say the brain has poor computational accuracy, we’re usually talking about the conscious brain we’re aware of. But our low-level motor actions and perceptions, coordinated by the brain, require a lot of precise computation. These low-level brain computations are the thing to compare to AI, not our conscious thinking. Our conscious mind is more like low-precision software running on top of an enormously powerf…

> But our low-level motor actions and perceptions, coordinated by the brain, require a lot of precise computation.

That accuracy is more likely achieved through fast, analog feedback loops than precise calculation.

Re: Why Is the Human Brain So Efficient? (2018)

#133

Post by anchpop »

deepnotderp wrote: post #109
shawnz wrote: post #54

Earlier quoted context omitted.

> The brain cannot simulate a turing machine. It does not have infinite memory, which is a requirement for a turing machine. In practice we call modern computers turing-complete even though they don't have infinite memory. The brain can simulate such a machine. > The brain has no such constraint. It is analog, and therefore infinite in State representation. If this mattered, then it would mean analog computers are mo…

Isn't the recent Google quantum "supremacy" experiment evidence against the extended Church-Turing thesis?

No, quantum computers as we understand them can be simulated by a turing machine

Re: Why Is the Human Brain So Efficient? (2018)

#134

Post by felipemnoa »

Digit-Al wrote: post #116
aeternum wrote: post #100

Earlier quoted context omitted.

Most dogs seem to acknowledge that humans are better when it comes to playing with toys, otherwise why would they bring them over for humans to throw?

Ah, now. See. You're mistake is thinking you can reason better than a dog. The reason a dog brings the toy to the human is because they know that the human is better at throwing and the dog is better at fetching. Teamwork, y'see. Now go forth and learn, and one day you too may be as smart as a dog ;-)

>>The reason a dog brings the toy to the human is because they know that the human is better at throwing and the dog is better at fetching. Teamwork, y'see.

Honestly I always thought that the dog was just being diligent and making sure that its humans did his daily exercise routine by throwing a toy.

Re: Why Is the Human Brain So Efficient? (2018)

#135

Post by catalogia »

SomeoneFromCA wrote: post #104
sharpneli wrote: post #79

Earlier quoted context omitted.

If world did run on real numbers that we could harness for computation I would be more than happy, because using those we would be able to perform hypercomputation. See https://en.m.wikipedia.org/wiki/Real_computation However this is forbidden by Bekensteins bound, so unless modern physics is horribly broken it’s ruled out at least in any sense visible to us even in principle.

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.

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.

Re: Why Is the Human Brain So Efficient? (2018)

#136

Post by Reelin »

TeMPOraL wrote: post #132
canjobear wrote: post #81

Earlier quoted context omitted.

When we say the brain has poor computational accuracy, we’re usually talking about the conscious brain we’re aware of. But our low-level motor actions and perceptions, coordinated by the brain, require a lot of precise computation. These low-level brain computations are the thing to compare to AI, not our conscious thinking. Our conscious mind is more like low-precision software running on top of an enormously powerf…

> But our low-level motor actions and perceptions, coordinated by the brain, require a lot of precise computation. That accuracy is more likely achieved through fast, analog feedback loops than precise calculation.

Like a giant stack of op-amps. (https://www.computerhistory.org/revolution/analog-computers/...)

Re: Why Is the Human Brain So Efficient? (2018)

#138

Post by Shorel »

dtnewman wrote: post #98

I imagine a group of dogs sitting around and asking "How are we so good at thinking about fun ways to play with squeeky toys?". The truth is, that our ability to reason about ourselves is limited by our ability to reason. Perhaps there are aliens out there who would laugh our cognitive abilities--their's being so much better than ours.

>Perhaps there are aliens out there who would laugh our cognitive abilities--their's being so much better than ours.

Yeah, but their brains would either be much bigger and/or use a lot more energy, or they will have a fundamentally different architecture (i.e. they are manufactured instead of evolved).

For the given amount of perceptions/calculations that our brain makes, and the hard constraint of being a biological process, we have pretty much fantastically efficient brains.

My computer, extremely slow when compared to the likes of DeepMind, has a power source of 750 watts, while human brains consume in average 12 watts.

Re: Why Is the Human Brain So Efficient? (2018)

#139

Post by dependenttypes »

sooheon wrote: post #43
criddell wrote: post #41

Earlier quoted context omitted.

Is there anything analogous to software in biology?

Biology is the ultimate legacy software running on one of the oldest platforms ever developed, the organic compounds. It is literally a giant genetic algorithm to write instructions (DNA) for manufacturing molecular machines (proteins) that interact with each other in an extremely complex graph of relations (protein pathways, i.e. control flow).

I am sure that I saw this exact message on HN before. Did you copy it from someone else or did you repost your own post?

Re: Why Is the Human Brain So Efficient? (2018)

#140

Post by ars »

jjoonathan wrote: post #105
dtnewman wrote: post #98

I imagine a group of dogs sitting around and asking "How are we so good at thinking about fun ways to play with squeeky toys?". The truth is, that our ability to reason about ourselves is limited by our ability to reason. Perhaps there are aliens out there who would laugh our cognitive abilities--their's being so much better than ours.

Less complicated systems successfully reason about more complicated systems all the time. Ditto for self-reasoning. See: bootloaders, update systems, and package managers. In order to prove that some kind of meta-cognition is inherently beyond our grasp, you don't just have to prove that the system we are attempting to reason about is more complex than ourselves, you also have to prove that the problem isn't meaningf…

> "a ruler can only measure less precisely than itself"

That's actually super interesting. How do you bootstrap (as it were) a ruler?

Like, assume you don't have any machine that is itself created by using a ruler (so no screws or gears, except hand cut ones).

Obviously it's possible, since we did it. But how do you do it?

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