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The computational power of the human brain

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Re: The computational power of the human brain

#31
post #6

> The brain has always been compared with a highly sophisticated computer. This is not strictly true. In ancient times, Plato compared the mind to a chariot pulled by two horses, representing emotion and reason. This reflected the importance of horses for transportation at the time. In the 1600s, Descartes saw the mind as akin to a mechanical clockwork machine, reflective of the clockwork and automatons built then. I…

Insightful. And the next era will describe it in terms of quantum interactions.

In terms of quantum computations. Most quantum interactions average into classical mechanics. And, no, it's not guaranteed. We are already beyond vague analogies like "two chariots". In the next era we probably will know equivalent (quantum) (noisy) computations for the brain activity.

Re: The computational power of the human brain

#32

> The brain has always been compared with a highly sophisticated computer. This is not strictly true. In ancient times, Plato compared the mind to a chariot pulled by two horses, representing emotion and reason. This reflected the importance of horses for transportation at the time. In the 1600s, Descartes saw the mind as akin to a mechanical clockwork machine, reflective of the clockwork and automatons built then. I…

Iain McGilchrist puts the matter of our lopsided repertoire of metaphors for the brain well in The Master and His Emissary (apologies for the lengthy quote): > This leads to a fundamental point about any attempt to understand the brain. It is a particularly acute case of the problems encountered in understanding anything. The nature of the attention one brings to bear on anything alters what one finds; what we aim to…

Interesting quotes, considering that our latest and greatest achievemnets in the AI field are based on "attention is all you need" transformers. Yet it seems that in a way we're so close, yet so far from replicating the full human attention in a machine. Maybe precisely because it can't be transformed into a a purely objective/measurable/scientific category.

Re: The computational power of the human brain

#33

Earlier quoted context omitted.

Do you mean that it's begging the question to assume that the brain comes to its conclusions via a physically deterministic procedure that terminates in finite time?

That's not what the Church-Turing thesis is about. The Church-Turing thesis says that any "effective procedure" (i.e. algorithm) for performing computations on natural numbers is equivalent to a Turing machine. It is generally accepted but cannot be proven because "effective procedure" is not defined. Indeed it can be seen as providing a definition for the term "effective procedure". To extend that to say anything ab…

There are different levels of argument depending on the precision of the definition of the concepts in play, which is unhelpful in general but also unavoidable.

I think that the folk definition of computation is so wide and vague that almost any physical process can be characterized as a computation in that sense. So brains (being physical) must be (folk) computers. The problem is that this doesn't get us anywhere because there are lots of equivalences and for practical purposes in there and what we really need is a characterization of the brain as it operates rather than what that operation might be modeled as.

As Searle says, you can simulate the processes of digestion but that doesn't mean that you have an artificial stomach that can turn food to energy.

Re: The computational power of the human brain

#34

This kind of question is meaningless, and I’m pretty sure it comes from the old view of neurons being somewhat akin to a 1-1 or many-1 digital switch (it isn’t). In fact, we currently don’t even know the full extent of the types of neurons in the brain or the way they function and interact [1] There are neurons that only fire when a certain percentage of their inputs are stimulated, some that have a temporal componen…

I dont think this is a problem. The computer nrural networks are closer to a single biological neuron than to a biological neural network. That provides tighter coupling. Long distance generalized "connections" can materialize as weight chains, recurence can provide timing.

Re: The computational power of the human brain

#35

> The brain has always been compared with a highly sophisticated computer. This is not strictly true. In ancient times, Plato compared the mind to a chariot pulled by two horses, representing emotion and reason. This reflected the importance of horses for transportation at the time. In the 1600s, Descartes saw the mind as akin to a mechanical clockwork machine, reflective of the clockwork and automatons built then. I…

The clockwork actually is the best kind of computer they had in the 1600s (in a clock it's dividing time units, they had mechanical calculators, and see also the antikyra mechanism), so that's a similar comparison

If in the future the comparison will be "quantum", then again, a quantum computer is also a kind of computer

Re: The computational power of the human brain

#36

Separately but related: decades ago, research was done into the "Bandwidth of Consciousness", that is: how much information can we consciously process. That research came up with the startling low number of about 40 bits per second _at_most_. Suggesting that the huge amount of information our senses take in is massively compressed before we become 'conscious' of it. References: W R Garner and Harold W Lake "The Amoun…

Funnily enough, large language models are similar. Gigabytes and gigabytes of numbers being processed, to input/output a few words per second.

Re: The computational power of the human brain

#37

> The brain has always been compared with a highly sophisticated computer. This is not strictly true. In ancient times, Plato compared the mind to a chariot pulled by two horses, representing emotion and reason. This reflected the importance of horses for transportation at the time. In the 1600s, Descartes saw the mind as akin to a mechanical clockwork machine, reflective of the clockwork and automatons built then. I…

I think the modern comparison to an advanced computer is far, far more accurate, though. If we look at each of the metaphors used to describe the mind in tje past, they got more sophosticated as time went on, so it stands to reason that the computer is our best comparison, to date. In a sophomoric way, it makes me wonder if that's what this is all about; our advancement as a species is a culmination of us trying to build something that works as our minds do, something that can perhaps reflect our minds since we really don't know of anything else that has achieved our (percieved?) level of consciousness.

Re: The computational power of the human brain

#38
post #7

Fascinating paper, though if you're looking for a quantified "computational power of the human brain" you won't find it. He concludes the brain isn't similar enough to a computer for a comparison to be made.

We will have to wait for an AI that can truly understand us. A jest I fear may be taken too seriously by the reality we seem to be quickly heading into. — I would guess that despite all the disparate systems, the basic computations will be similar. Different parts of our generalized connectome, making different connections at different time frames. I.e. time and multi-signal integration with decay, positive and negat…

Not even we understand ourselves. I wonder if it's even possible for a machine to do it. And if it is possible and we manage to create this machine, there's still the problem of explaining us to ourselves.

Re: The computational power of the human brain

#39

> The brain has always been compared with a highly sophisticated computer. This is not strictly true. In ancient times, Plato compared the mind to a chariot pulled by two horses, representing emotion and reason. This reflected the importance of horses for transportation at the time. In the 1600s, Descartes saw the mind as akin to a mechanical clockwork machine, reflective of the clockwork and automatons built then. I…

This is going to sound really obvious, but you can only make analogies with things you know. Or better yet, something known and understood by the people around you.

I'm sure there are some subtleties in chariots being pulled by two horses that I'm not aware of, and so Plato's analogy doesn't work for me.

We won't be able to compare the brain to anything better than a computer until we either understand the brain better, or until we understand some other brain-analog better.

Re: The computational power of the human brain

#40

Separately but related: decades ago, research was done into the "Bandwidth of Consciousness", that is: how much information can we consciously process. That research came up with the startling low number of about 40 bits per second _at_most_. Suggesting that the huge amount of information our senses take in is massively compressed before we become 'conscious' of it. References: W R Garner and Harold W Lake "The Amoun…

I think using terms and concepts from classical Information Science when talking about brains is a non-starter. To speak HN lingo, it's like measuring a computer's performance while it is in the middle of compiling the Linux kernel and training a GPT model.

Sure, the throughput for these discrete tasks was low, but the brain is not discrete. It is a heavily optimized complex system that can be taught to predict complex vector interactions in an instant and be correct enough every time. It can spot tiny movements in a sea of leaves while searching for a green herb in a green forest and immediately switch to group preservation mode when it becomes clear the movement is a tiger.

> devise a way of measuring bandwidth-in to consciousness vs bandwidth-out.

This is a dead end, "consciousness" is just a tiny goal-setting and evaluation layer on top of a a gigantic stack of "unconscious" processes. That stack is so powerful that we even use its mysterious, chaotic power to outsource formerly conscious processes after enough repetition.

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