> We can't come up with anything better, and have ruled out everything we reasonably can at this point in our inquiry, so therefore the findings support the only remaining plausible mechanism.

No, quite the opposite. As the top-level comment pointed out, this is god-of-the-gaps reasoning. If you fail to find discrete evidence of consciousness anywhere in the brain, the natural conclusion is not "it must be an inscrutable quantum phenomenon that we have been unable to investigate thus far." The natural conclusion is that consciousness is simply not a discrete phenomenon.

We have zero scientific evidence that a mechanism for consciousness is hiding in some part of the brain, waiting to be found. Rather, there exists a popular intuitive dualism that suggests our own consciousness must be more than an emergent neurological phenomenon—that it must be a discrete thing caused by an exotic mechanism with non-computable properties. Ideas like quantum microtubule consciousness (or "orchestrated objective reduction") are the product of motivated reasoning: They exist only to keep dualism on life support, in the face of adverse evidence.

I don't have a methodological problem with this study in particular. If we take quantum microtubule consciousness seriously, it's a perfectly good study. But we shouldn't take it seriously—it's a ridiculous ad-hoc hypothesis that mashes together various cutting-edge fields of science with a hefty dose of quantum mysticism in order inject doubt and escape the potentially upsetting conclusion that consciousness is not a "real" phenomenon in the way that we perceive it to be.

Agree. It's incredibly frustrating seeing takes on science by engineers on HN. It's as bad as, if not worse than, the takes I see about politics around here.

For context, this is what the paper itself says:

> In order to experimentally assess the contribution of MTs as functionally relevant targets of volatile anesthetics, we measured latencies to loss of righting reflex (LORR) under 4% isoflurane in male rats injected subcutaneously with vehicle or 0.75 mg/kg of the brain- penetrant MT–stabilizing drug epothilone B (epoB). EpoB-treated rats took an average of 69 s longer to become unconscious as measured by latency to LORR. This was a statistically significant difference corresponding to a standardized mean difference (Cohen’s d) of 1.9, indicating a “large” normalized effect size. The effect could not be accounted for by tolerance from repeated exposure to isoflurane. Our results suggest that binding of the anesthetic gas isoflurane to MTs causes unconsciousness and loss of purpose-ful behavior in rats (and presumably humans and other animals). This finding is predicted by models that posit consciousness as a property of a quantum physical state of neural MTs.

> Our study establishes that action on intracellular microtubules (MTs) is the mechanism, or one of the mechanisms, by which the inhalational anesthetic gas isoflurane induces unconsciousness in rats. This finding has potential clinical implications for understanding how taxane chemotherapy interferes with anesthesia in humans and more broadly for avoiding anesthesia failures during surgery. Our results are also theoretically important because they provide support for MT-based theories of anesthetic action and consciousness.

Let me emphasize:

> This finding is predicted by models that posit consciousness as a property of a quantum physical state of neural MTs.

If people here want to criticize the paper, I want to see some citations of passages from the fucking paper, and not some hur-dur quote from a popular science article meant to convey the paper to a lay audience. But you know, 99% of the paper would be indecipherable to most people here, so all we get is these surface level takes that wastes everybody's time.

The intellectual laziness in these comments is galling.

The microtubule "quantum consciousness" hooey has been around since the 90's. It was paid lip service in my biochemistry and molecular biology classes almost as a joke when covering dynamic instability and transport.

While it wouldn't be strictly impossible to test, it's very much cut in the same cloth as string theory.

> thus it's presence must mean life if there

Nobody said that. It's on you for making the leap, whether out of hope or misguided combativeness, to the assertion that it must mean life, which I don't recall ever being stated by any of the researchers involved or any reputable articles.

Have we not pointed telescopes into space and seen the way light bends around a black hole? I guess in a way it's true that nobody has conclusively "seen" one (since they don't emit light), but by that logic nobody has conclusively seen the hole in the middle of a donut either.

> It's not so uncommon in science to come to a strange conclusion by excluding all "reasonable" alternatives.

That is not what happen in the article, or to my understanding in this field of research.

> For example, black holes have a similar status: no one has conclusively seen one, but we know of no mechanism for matter to support itself beyond a certain density, so black hole it is.

Comparing the equation based methods of physics, often called a "hard" science, to neurology or biology, often called a a "soft" science, is not going to be an apples to apples comparison.

This sounds like the whole "we've never seen a species evolving". Much like fossils, radioactive dating, geology come together to give us a picture of evolution, we have tons of real evidence for black holes. But we even have two actual pictures now.

yes, but in this case, nobody has excluded all the more probable alternatives.

Discrete conclusions with no continuous path connecting them? Apt!

Your theory having serious problems but no competitors does not actually solve the serious problems with it.

If I can't tell you why the sky is blue, it doesn't make your theory that it's green more likely to be right.

We're talking about people like Marvin Minsky or Hilary Putnam, who have made very significant contributions to the discourse. And if Max Tegmark thinks your claims are a bit too far out, you've got your work cut out.

The ability to invalidate or critique a solution does not require knowing any part of the solution.

You can get to this conclusion more directly by noting that computational complexity of any Turing simulator of anything more than a trivial system increases very fast as the precision of the initial conditions for the simulation increases. Even the shift map exhibits this phenomenon.

This can be an even more severe boundary for prediction than the actual measurement accuracy.

In the discussion about determinism vs free will, this leaves us with the situation that we can predict what somebody will do even if we assume perfect measurements, but will only be able to produce this prediction after the fact except for very short term predictions.

You've outlined what I reckon is the appeal of "quantum consciousness". I personally feel that randomness doesn't help to explain free will any more than determinism. I'm more inclined to believe that free will (in the strictest sense) is an illusion.

Why would “my decisions are determined by sub-nuclear divine dice rolls” be any closer to free will than “my decisions are determined by algorithms operating on my sensory inputs and memories”? What’s more “free” about introducing that factor?

Randomness just introduces branch points into the linear flow of deterministic states. Since you do not control the branch points or create them, this does not give you free will.

We don't actually know if quantum physics has real randomness or not. Quantum collapse is an unsolved problem.

> I could see early attempts at [introducing randomness] causing a form of LLM schizophrenia because the neural network wasn't resilient enough to the induced error.

1. This is actually already done. Temperature parameter controls amount of randomness.

2. Neural networks are quite noise resistant.

Randomness does not give you free will, any more than determinism does.

What do you mean by free will?

This is possibly one way to solve it, but I think there is a simpler way, following causal chains and the laws of thermodynamics.

We clearly have systems that can absorb energy for later use - creating a natural "pause" in the causal chain. Each of these pauses create a possible future that is not yet realized. The longer this energy is held, the larger this possibility space becomes.

Free will becomes that ability to hold the pause with intention, and then select from the different possible futures that have been created.

Determinism does not interfere with this in any way. The causal chains all follow the basic deterministic laws of physics. There is space for choice created by holding energy instead of immediately dissipating it.

No quantum mechanics required at all.

> how you square free-will and determinism (and subsequently consciousness)

I've never seen this as an issue. Even if something is fated, it's still you making that choice.

You ate whatever you ate for lunch yesterday. It's already happened. You still made the choice.

> free will exists somewhere/in a form we cannot directly observe

John Conway has a rather neat explanation of this in the Strong Free Will Theorem.

https://www.ams.org/notices/200902/rtx090200226p.pdf

Being neat doesn't necessarily mean it's correct, but it's compatible with what we know about physical reality, and solves some otherwise rather tough and paradoxical facts about experienced reality, so I'm a fan.

> But, we know there exists places that we cannot directly observe or perceive, aka quantum uncertainty, represented by σxσp ≥ ℏ/2 [1].

> So based completely in theory, I figure the only way we square FW & determinism, is that free will exists somewhere/in a form we cannot directly observe, and it manifests as tiny influences that add up, in the complex system that is a brain.

These two things not only don't follow from each other, the first one actually all but refutes the second.

First of all, Heisenberg uncertainty affects all physical systems, but clearly not all physical systems are conscious.

Second of all, there is no pattern allowed to exist below Heisenberg uncertainty. That is, if you could determine exactly the momentum of a particle, the particle could literally be anywhere in the universe, with equal probability: there is no bias, it wouldn't be more likely to be here or there. So this is pure randomness, there is no "consciousness signal" you could extract from it.

Or, to put it another way, if our consciousness was a result of Heisenberg uncertainty, that would mean it's a purely random phenomenon, and every human at every time would be exactly as likely to type the next word in this comment, start running in a random direction, gouge out one eye, or any other thing they are capable of doing. There is, in a very fundamental sense, no way to get patterns or intention out of Heisenberg uncertainty.

Besides, the best way to square "free will" with determinism is Compatibilism. Every human is an automaton whose behavior is fully determined by genetic and epigenetic make-up and by everything they've ever learned and otherwise experienced. In a fundamental sense, my whole life's course was determined the moment I was conceived; but still, in any given situation, what I will do is different from someone else might do, because they have a different history and thus different values and biases. There is no magic that allows some "fundamental me" to "choose" how some electro-chemical processes will fire in my brain, any more than I could "choose" to emit electrons from the tips of my fingers. But that doesn't mean that I (the adult I am today) would do the same things Hitler did if I were somehow catapulted into his shoes today.

What does it matter why you can't predict the future state of a brain?

are we really citing ChatGPT in comments now

> Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes.

> If anything, it appears that neural networks are far further along than any quantum mechanism for approximating whatever "consciousness" actually is? And neural networks are absolutely not quantum mechanical.

I know next to nothing about either, but I wanna try to disagree with that.

LLMs fool people into believing they‘re conscious, because they‘ve been trained on extraordinary amounts of thoughts and data outputted by the world‘s top conscious creature. They appear conscious because consciousness is in the training data.

To me, neural networks more closely mimic the brain in what I would (poorly) call „bodily functions“. I include language processing and speech in this definition.

There are people that don‘t have an inner monologue - which is totally fascinating to me - who are perfectly conscious like everyone else. Simon Roper, who doesn‘t, has fascinating YouTube videos on these topics.

> Yes but AFAIK, reality is "quantum" in the sense that something like the scale of Avogadro's number (N=10^23) quantum processes interact and average out to typical classical behavior. It's only in limited situations where the actual quantum mechanical nature pops up in the macro world, right? (eg Bose-Einstein condensate, the ultraviolet catastrophe, energy bands of semiconductors, emission spectra, etc).

This is not very clear at the moment. Of course, observations make it obvious that classical objects don't behave like quantum objects, and all quantum objects we know of are small, and all classical objects are big.

We even know of one mechanism that prevents certain quantum effects from influencing large systems - decoherence. Decoherence explains why, when a quantum system that is all in the same phase interacts with a large system where everything is out of phase, the various parts of the quantum system also quickly go out of phase, and thus can't constructively or destructively interfere with each other any more. This explains for example why, if you repeat the double-slit experiment with ping pong balls instead of atoms, or if you repeat it in a dense gas at high temperature, you won't see the interference patterns form.

However, we don't understand at a high level why it is that quantum experiments only have "a single result". Basically the schrodinger equation applied for the double slit experiment, even taking decoherence into account, still predicts that the particle-wave will move through both slits to some extent. And yet, with or without decoherence, we only ever see a single photon or tennis ball hit the screen, with some probability that can be deduced from the square of the amplitude of the Schrodinger function. And even worse, this single measurement outcome only happens if the quantum particle has hit a classical screen. If instead at the same distance we only have other quantum particles, then it can actually hit several of them, and change all of their positions and momenta. This despite the fact that, of course, even the classical wall itself is made of particles which should obey the same laws of quantum mechanics.

> If anything, it appears that neural networks are far further along than any quantum mechanism for approximating whatever "consciousness" actually is? And neural networks are absolutely not quantum mechanical.

Neural networks are also way less power efficient. Quantum computing allows us to calculate things that would take a lot of power or time to calculate (not calculate things that are impossible). If one could create consciousness with classical physics it wouldn't prove anything about how the human brain works. In fact if it was wildly less power efficient it might even suggest non-classical physics in the brain.

> The idea that Penrose posited is intrinsically HARD to measure. Moreover, consciousness itself is not well defined to begin with.

Indeed. Penrose's hypothesis is very much in the untestable realm. Until there is some way to test it, it deserves little consideration. If there is something like an ad hominem praise, taking this seriously might be a good example.

While the behaviors of fermions and of bosons are indeed responsible for what you consider miracles, I fail to see which is the special relationship between the Fermi-Dirac and Bose-Einstein statistics and "quantum entanglement" that you have in mind.

From Wikipedia's 1st paragraph: "While consciousness is being aware of one's body and environment, self-awareness is the recognition of that consciousness."

From that, I think it's clear that defining self-awareness relies on the definition of consciousness as opposed to the other way around. I don't think it moves us any closer to a definition of consciousness.

I would completely agree that current LLMs are not conscious, but it seems problematic to defining consciousness that (unless trained not to, as public facing ones have been) they will tell you all about how they are.

https://www.vox.com/future-perfect/2024/3/15/24101088/anthro...

"Self-awareness with a theory of mind" doesn't account for qualia, which IMO are the most important part of consciousness discourse. What people mean when they say "consciousness" has more to do with a certain ineffable sense of here-ness and me-ness that I think is closely tied with qualia. If you limit your definition to "self-awareness with a theory of mind," I think you're going to mostly talk past people who are trying to engage with the so-called "hard problem" of consciousness.

> Is consciousness even real, or is it just a feeling? And I've never heard a satisfactory argument that it is real.

That you wrote this comment is ample evidence it is real, unless you are using a very non-standard definition of consciousness.

Penrose speculated about the source, but was Stuart Hameroff that brought the idea it could be the tubules to Penrose's attention. Hameroff thought anesthesia nerfed the tubules properties, which then caused loss of consciousness.

Then there's the recent articles on how the tubes might be able to entangle signals, which was from experimental research on meta materials.

I realize all of this is speculative at this point, and nobody is trying to say YES this is how it works. It's simply exploring one possibility, in a positive way, that allows us to think further outside the box.

Is it really that new? Hameroff and Penrose have been making wild claims about microtubules since at least 1996: https://www.sciencedirect.com/science/article/abs/pii/037847...

You sure showed me.

Have you used one?

In just 2-3 years we've gone from primitive LLMs to LLMs reaching Graduate PhD-level knowledge and intelligence in multiple domains. LLMs can complete almost any code I write with high accuracy given sufficient context. I can have a naturalistic dialog with an LLM that goes on for hours in multiple languages. Frankly (and humblingly, and frighteningly) they have already surpassed my own knowledge and intelligence in many, probably most, domains. Obviously they aren't perfect and make a lot of errors - but so do most humans.

Those scandals are an absolute disgrace indeed, but please remember it's a very small percentage of scientists involved (I hope!).

I have to say it makes me feel bad that as soon as I identify as a biologist, I get smacked in the face with western blot scandals. My god, the damage these frauds have done to our reputation. I'm so sorry for it.

Penrose is a scientist gone crackpot in the tradition of Josephson. His "I can do math because I am a thetan" shtick is based on a ridiculous misunderstanding of Godel since Godel's theorems don't apply to a piece of wetware which is by no means consistent or complete. (e.g. if he does math by being a thetan why can't he solve Collatz?)

Wolfram is something else. A New Kind of Science isn't really wrong yet it's not really right. It's sad to see him spend decades looking for more systems like Rule 30 and finding systems that are similar but not so simple, not so pretty, and he never gets an insight out of it that really applies to anything else. He's like a crackpot in that he works tirelessly on a research program that's unconnected to anything else anyone else is working on, however. Maybe that comes out of being rich and not having to apply for grants. On the other hand, there are major fields of physics, such as string theory, which very well be based on a delusion, yet in that case it is a shared delusion.

In the pandemic he went on a vainglorious and grandiose quest for a "theory of everything" yet he has the good judgement to base it on causal networks which I think is one of the best grounded approaches to quantum gravity (e.g. given two points in space-time aren't they spacelike or timelike or lightlike and in the last two cases isn't one of them in the future or past of the other?)

Basically… yes.

I mean I have an internal model in the making since I started my biochemistry bachelor in 1999, I moved through a molecular biology master into a biophysics PhD (where I also disrupted microtubules to investigate molecular processes of GPCRs), then into a professional career as a bioinformatician in the genomics field.

And when I read this:

“Wiest and his research team found that when they gave rats a drug that binds to microtubules, it took the rats significantly longer to fall unconscious under an anesthetic gas. The research team's microtubule-binding drug interfered with the anesthetic action, thus supporting the idea that the anesthetic acts on microtubules to cause unconsciousness.”

It certainly sounds probable microtubule disruption would do that but there are so insanely many ways that this could be explained using classical, non-quantum hypotheses (that need testing!), and microtubules serve so many different functions in cells, that the quantum theory falls completely outside of the possibilities of my internal models. I have no need of such an outlandish hypothesis.

Extraordinary claims require extraordinary evidence, and this paper is not it. Sure there is a small chance I’m going to be wrong but Bayes would agree with me it’s an exceedingly small chance given all priors.

Just the scale difference between microtubules and whatever gives our brain that sense of consciousness is so unimaginably vast and complex that simple statements such as in TFA are really hinting at (feigned for attention?) ignorance.

Trust me.