Single-celled organism has evolved a natural mechanical computer | Hacker News Reader

Single-celled organism has evolved a natural mechanical computer

newscientist.com

61 pointsvijayr0240 comments

This article appears to be based on this article in bioRxiv[0]. It references some supplementary videos, so perhaps it's in some work that is yet unpublished?

[0]https://www.biorxiv.org/content/10.1101/2021.02.26.433123v4

Using microtubules. Very interesting. The same structures found in our brains, and posited by Roger Penrose and Stuart Hammeroff as being key to consciousness. Penrose proposes that they are using some previously unknown quantum phenomenon to kickstart our conscious minds - but whatever their internal workings, if they can act as computational devices, estimates for our brains' computational power must rise by several orders of magnitude.

Is there a good scientific explanation why quantum phenomena are required to explain consciousness? Or in other words, is there a reason to rule out consciousness as a natural emergent property of the macro-level structure and composition of our brains, without delving into the quantum realm (beyond what is necessary to explain the operation of the cells themselves)?

We're just stuck at a dead end as regards the hard problem of consciousness. Quantum theory appeared to have potential because of the apparent links between consciousness / observation and wave-function collapse. This may not help.

The current zeitgeist appears to be denial that consciousness exists at all. I don't think this helps either.

If I had to take a punt I'd say that we can't find a solution because it's the substrate of everything, so by definition can't be measured by us.

> The current zeitgeist appears to be denial that consciousness exists at all.

That’s odd, arguably it’s the one thing we know exists.

> because it’s the substrate of everything

Recommend checking out Bernardo Kastrup (two PhDs, many books and videos on YouTube) who argues that mind is fundamental.

> That’s odd, arguably it’s the one thing we know exists.

They do it by changing the meaning of the word "consciousness" so that they can then show that this new thing they've defined doesn't exist. It's a remarkable strawman.

If consciousness doesn't exist, who is it that can disprove it, and why should anyone listen? It's a bit like proving the universe is a simulation or not. These can never be proved or disproved.

It's quite silly to deny consciousness though! It's similar to deny one's existence. So philosophy and psychology shines some light on these questions.

I don’t think “two PhDs” is the flex you think it is to most people with PhDs.

“I have a PhD and I am unimpressive”

Personally, I was smart enough to stop after one phd.

Checked him out, he doesn't have his own RationalWiki entry, just a footnote under Deepak Chopra https://rationalwiki.org/wiki/Deepak_Chopra

lesser kook.

Are there good articles that explain why it seems we're at a dead end in explaining consciousness without needing to go subatomic? Because I've never read anything convincing that concludes consciousness, when described as an emergent property of the macro-level operation of the cells and chemicals of our brains, is proven to be impossible.

Other than popular science writers or physicists thinking they understand everything because they understand QCD, who said consciousness is stuck at a dead end for a lack of theories? The current standard hypothesis is that our synapse based computational network is more than sufficient to explain consciousness, we just don’t have the tools to prove or disprove the same. Connectomics research is still at its infancy unfortunately. Trying to invoke QC where we haven’t even gotten the bandwidth to prove or disprove a far simpler theory seems like a bad idea.

Remember that quantum theorists have a strange dog in the race due to the whole wave-function-collapse by an observer thing.

This gives them an unusual take on observers and consciousness.

While everyone else tend to be happy with "consciousness is a physical computation", they tend to need/want something more.

As far as I can make out David Deutsch started Quantum Computation to be able to have a quantum observer to probe the nature of quantum reality.

>>"As far as I can make out David Deutsch started Quantum Computation to be able to have a quantum observer to probe the nature of quantum reality."

That's very surprising to me, because Deutsch is heavily in the Everett interpretation branch of possible quantum interpretations (pun intended).

So, he doesn't need any wave-function-collapse magic to explain quantum mechanics.

>>"Remember that quantum theorists have a strange dog in the race due to the whole wave-function-collapse by an observer thing."

That's very insightful.

>> That's very surprising to me, because Deutsch is heavily in the Everett interpretation branch of possible quantum interpretations (pun intended).

He considers a working QC as basically an experimental confirmation of the many-worlds interpretation.

Something like: "So tell me, these amazing parallel computations - where exactly do you say that they are being computed again if not in the parallel worlds?"

There is a nice interview with him in Wired that touches this briefly:

https://www.wired.com/2007/02/the-father-of-quantum-computin...

Check his answer to:

"So what prompted you to start thinking about quantum computing?"

My take is that for him the QC started as a thought experiment to get a quantum observer to sidestep the whole wavefunction collapse by a classical observer problem.

>> That's very insightful.

Thanks.

You're redefining consciousness here to mean physical awareness in the brain, though. That is not the same thing as conscious experience. Using the physical material of the brain at the electrochemical level to try to explain the hard problem of consciousness is a bit like trying to use the water cycle to explain the weak force in nuclear physics.

I'm talking here about the hard problem of consciousness: https://en.wikipedia.org/wiki/Hard_problem_of_consciousness

The only solutions which don't involve a fundamental reworking of physics basically end up denying that consciousness (as phenomenal experience) exists at all.

> You're redefining consciousness here to mean physical awareness in the brain, though.

Where?

> The current standard hypothesis is that our synapse based computational network is more than sufficient to explain consciousness.

This is "strong reductionism" which comes under the heading of "Rejection of the Problem" in the linked article. GP is essentially denying that the hard problem exists.

Try reading that sentence with the definition of consciousness you'd normally use.

It seems like you're assuming the author intended to redefine the word, but I still don't see where that redefinition took place.

What I mean to say is that the author subscribes to a theory of consciousness "strong reductionism" which redefines it to mean "things we can observe", in as much as it states that it solves for all thing which 'need to be explained'.

> in as much as it states that it {solves for all […]}

That's as far as I can parse this bit of sentence. Could you reword, please?

Here's their argument:

1. Consciousness is the activity of the brain in response to stimulae, or things that people report that they can experience. These are the only things which need to be explained.

2. We can measure these and explain them with reductive science.

3. Therefore we can explain consciousness.

But of course this is a redefinition of consciousness because it ignores phenomenology. And that also needs to be explained.

> But of course this is a redefinition of consciousness because it ignores phenomenology.

No, it isn't, and it doesn't.

1. Deliberate motor movements are caused by signals from the motor cortex.

2. Poets have written poems about phenomenological experience.

3. Therefore, phenomenological experience causes activity in the brain.

It's not a redefinition; just a challenge of your assumptions.

Looks like you invented your own problem and are now claiming physics cannot explain it as it exists today.

If there truly is something of “I feel it” factor that’s not just “physical” as you say it, then this can be disproven easily by seeing if a machine can attain consciousness. If that never happens then good for your theory. If it happens at some point then you’re wrong. Until then it seems like a fairly non scientific philosophical argument at best. I.e., it’s still worth having but let’s not try claiming your microtubules are tingling the quantum realm to make you think shall we?

I'm afraid there's nothing special about a machine attaining consciousness. Many of the approaches to the hard problem would happily work with conscious machines. This may not be a question for science at all.

Nobody was able to rule out conciousness as purely emergent from plain observable behavior of neurons without any need for quantum or pixie dust or the essence of life.

That's like arguing that no one has been able to prove that you can't make a universe out of extremely large volumes of soup.

The phrase that applies here is "Extraordinary claims require extraordinary evidence."

If you're going to claim that consciousness is fully explainable as plain wet chemistry, you're going to have to provide more evidence than a sentence that starts with "Well, obviously..."

"Extraordinary claims require extraordinary evidence." Well, the claim that consciousness cannot be an emergent phenomenon strikes me as a much more extraordinary claim, and thus the burden of evidence is clearly on those. I suspect this warped perception is to religious and esoteric upbringing.

Well, everything we ever explained in biology and related fields turned out to be fully explained by plain wet chemistry, so claim that conciousness is not is quite extraordinary.

Conciousness is a function of the brain like digestion is a function of the stomach. Why not explain digestion with spooky quantum mechanics?

> Is there a good scientific explanation why quantum phenomena are required to explain consciousness?

I think it is simpler than all that: quantum phenomena belong to our description of reality, as also does consciousness.

Assuming both are valid and explanatory, it should not be a surprise to see overlap. However, if one believes that one or both of these is false, the question is not to explain one using what we know of the other, but to disprove it using what we believe we know to be true.

Is consciousness required to explain quantum phenomena, or simply our only means?

Inasmuch as I don’t want to discredit any theory without proof of their wrongness, this is so out there it’s a bit fantastical. More importantly it seems like a solution in search of a problem. As one philosopher is quoted in the criticism section of the Wikipedia article on this theory: “ Pixie dust in the synapses is about as explanatorily powerful as quantum coherence in the microtubules.”

I’m not going to say Penrose should stick to stuff he knows about; after all schrodingers hypothesis about life were prescient and chilling to read even today. But if some dudes gonna make theories about things he’s not an expert in, he better make sure it’s at least slightly warranted and a bit more rigorous.

The other issue is that confluence of two disparate fields Always attracts cooky theories like this because no expert in the individual field (at least the good ones) would feel qualified to comment about the other field they have limited knowledge about, so there’s a vanishingly small number of people who can mount a real defense against this. Fields like quantum consciousness, longevity research and crypto are further fueled by stoners who think they’ve figured out the universe because they had an acid trip. So it’s even more of a futile exercise to try and correct these people.

[1] https://en.m.wikipedia.org/wiki/Orchestrated_objective_reduc...

I always took the microtubules theory as a tentative to reconcile three opinions:

the physical/biological world is merely mechanic

our consciousness is based on physical phenomena

our consciousness is more complex than any computer/Turing machine

given that the theory feels like it is just a way not to have to change one of those belief.

Our consciousness can be based on physical phenomena without quantum handwavyness. Just look at all the mechanics that already exist within neurons, glia, and their associated proteins. Honestly I think its a bit absurd to keep looking for something else when all of that already seems pretty fking magical. It is immensely complex and we still don't fully understand it, but it doesn't seem like we need any special quantum sauce to produce our thought processes and behaviors.

But the way the microtubules are doing computation as described in this paper is decidedly not based on quantum phenomena, but rather a fairly simple mechanical state machine. It's not at all clear that this type of computation, even if it existed in the the brain, would raise the total processing capacity of the brain significantly. I mean, it could, but I certainly don't see that it "must".

Every synapse is itself a protuberance caused and maintained by microtubules. If the previous estimates of computational power are based on the mere integration of synaptic activity (I'm looking at you, Kurzweil), and as of late we are coming to view the individual synapses as full computational elements in their own rights, then this is essentially adding at least another order of magnitude or two to the equation beyond our modern understanding.

This is because every single synapse would itself additionally be placed and supported by a state-machine-based computational system local to it, tethered to every other state-machine-based computational system in the same neuron, including synapses at both the input and output side, and a much larger computational complex of systems within the body of the cell.

Computational systems built upon computational systems upon computational systems, all complexed together and communicating at multiple layers of the hierarchy with bi-directional feedback.

Possibly a new dimension of computation indeed, but interesting for many other reasons in all types of cells.

Microtubules are highly prevalent, reconfigurable, dynamic structures.

Did you know that inside a cell there is over 20atm of pressure? That's some force. Even an abacus in every cell changes the game.

https://en.m.wikipedia.org/wiki/Microtubule

Article is cut off in the third paragraph.

archive.is and archive.org versions don't fare any better.

The video told me most of what I wanted to know: https://www.youtube.com/watch?v=CzAoJzlkzZ4

Article has a link to the lab, which may have more information (I didn't check).

The real article is on Biorxiv:

https://www.biorxiv.org/content/10.1101/2021.02.26.433123v3

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