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New research suggests our brains use quantum computation
- isaacfrond 4y agoI haven't found the original article yet, but from the summary: using a special MRI machine they found MRI signals that resemble heartbeat evoked potentials, a form of EEG signals. Apparently, these signals are only detectable if they are entangled. Hence the brain is a quantum computer. That there are entangled particles in the brain is no surprise. Any cup of coffee will have a million. That the brain uses quantum computing is a bit of a reach it seems.
- bondarchuk 4y agoThe paper is linked right at the bottom of the article: https://iopscience.iop.org/article/10.1088/2399-6528/ac94be https://iopscience.iop.org/article/10.1088/2399-6528/ac94be
- dsego 4y agoSir Roger Penrose & Dr. Stuart Hameroff have researched and written about possible quantum processes in the brain's microtubules.
- andybak 4y agoI read the Penrose book years ago and it felt like a huge logical leap (in a bad way). At first glance so does this but I feel it would make the universe much more interesting if this turned out to be true so fingers crossed.
- cesaref 4y agoAgreed, I struggled to follow his reasoning when I read his book, but I also am aware it was a popular science book, so maybe it was dumbed down for the general public? I've not tried to track down more academic work in this area, maybe the evidence is more compelling?
- vesinisa 4y agoI intuitively believe that free will is incompatible with determinism. This seems to be a very divisive issue - many people seem to strongly believe that free will is either an illusion or readily compatible with determinism.
- reuben364 4y agoIs this meant to be a reply to the above comment? My thoughts are as follows: If one can decompose one's subjective experience into an agent and the environment it interacts with, then there are several variations I can think of: - The agents actions are entirely determined by its environment - The agents actions form a probability distribution determined by it environment - The agent actions from their environment are annotated in some way that we haven't or can't have thought of that represents what the agent is. In my opinion, something that we can't think of or experience and something that doesn't exist are indistinguishable and we shouldn't really separate them except for making this statement. - There is no agent and subjective existence is merely one route down immutable decision tree that is our choices and their consequences. None of these options really intuitively sound like free will to me. Ultimately thinking along these lines requires separating the agent from the environment. EDIT: I see now the reply is to the YouTube link which I missed
- Ialdaboth 4y agoI'm more and more convinced this is... not exactly a false dichotomy per say, but at least a tricky one : you can have both free will at the micro level (any individual), and determinism at the macro level (any sufficiently large group of humans, considered in aggregate) at the same time.
- FeepingCreature 4y agoOf course, the debate is generally about whether you can have both free will at the macro level (the human brain) and determinism at the micro level (particle physics).
- justsee 4y agoLex Fridman interviewed Penrose on this topic recently (2020) and Penrose delivered a very accessible walkthrough of his historical and current thoughts on the topic. https://youtu.be/orMtwOz6Db0?t=2654 https://youtu.be/orMtwOz6Db0?t=2654 (Deep-link half-way through to his discussion on microtubules)
- emmelaich 4y agoI think https://en.wikipedia.org/wiki/Paul_Davies https://en.wikipedia.org/wiki/Paul_Davies would be happy to see this too.
- jcims 4y agoFor anyone interested in a bit more context around microtubules, here's a video that shows how they are built and used to support cell mitosis https://www.youtube.com/watch?v=0JpOJ4F4984 https://www.youtube.com/watch?v=0JpOJ4F4984 I wish my biology class back in high school had videos like this.
- zogomoox 4y agoHow can you tell entangled particles from non-entangled ones? I saw another article today about keeping quantum systems entangled for a long time by firing lasers in a Fibonacci pattern, but what allows them to see whether its still entangled?
- lisper 4y ago> I haven't found the original article yet https://iopscience.iop.org/article/10.1088/2399-6528/ac94be/pdf https://iopscience.iop.org/article/10.1088/2399-6528/ac94be/...
- marginalia_nu 4y agoStrictly speaking, most modern electronics are quantum computers already. You almost can't make a transistor without relying on quantized excitation states. Quantum effects are so prevalent on a nanometer scale it's more often a problem than it is a boon.
- simonh 4y agoThey're saying brain processes must have interacted with the nuclear spins, and those brain processes must be quantum. But everything in the brain is quantum at some level, because all of reality is quantum. It's quite possible this is an entirely irrelevant side effect. The brain is a complex living system with all the features of biological systems completely aside from the fact it's also the organ we think with, as against the organ we breathe with, or that processes our blood. I'm not excluding the suggestion that quantum effects have macroscopic implications, but for example transistors only work due to quantum mechanical effects. That doesn't make all computers containing transistors 'quantum computers' in the accepted sense. I don't want to be reflexively negative though. One thing we are sure of is that biological systems are unbelievably complicated, and almost every aspect of biological systems has some sort of feedback loop or side effect on everything else, many of which do affect function. Everything we learn, this included, is valuable and could turn out to be significant.
- fauigerzigerk 4y agoIf I understand correctly, the paper claims to have found quantum effects that correlate with cognitive processes.
- simonh 4y agoYes, but very tenuously, and as we all know correlation is not causation. Heartbeat evoked potentials are like a clock signal or drum beat through brain activity. The spin of these protons is synchronised with changes in these potentials, and the potentials play a role in cognitive function. Imagine a band playing a song. The drum beat drives the rhythm and plays a central role in whole performance, but these protons may well be like sand grains bouncing on the surface of the drum. Also bear in mind that nothing they studied or observed correlates in any way with the specific quantum processes that occur in quantum computation.
- fauigerzigerk 4y agoGreat analogy! I understand what you mean.
- awinter-py 4y agoclearer overview of the MQC MR modality they're talking about + the ZQC baseline (in the context of its normal industrial / science use) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3732750/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3732750/
- jqpabc123 4y agoI know for a fact that consciousness is an emergent property of binary logic. Just keep writing bigger and more complex software and one day --- pooff! By some magic neither planned nor understood, the binary logic playback device (aka a "computer") will jump the fence at the reservation for inanimate objects and start writing it's own software. I know it's true because people make movies about it --- and lots of people on the internet *believe* this is how it works. If enough people *believe*, over time it becomes real. No logic or proof required, this is just how religions work. A hammer *can* drive it's own nails --- you just have to believe hard enough.
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- ben_w 4y agoDon't get me wrong, I recognise the snark, but GPT-3 already writes code if you ask nicely. Biggest problem in this area, is nobody really knows what "consciousness" means (or if they are completely certain, then they also disagree with someone else who is also completely certain and/or deny the logical consequences of that definition).
- jqpabc123 4y agoGPT-3 already writes code if you ask nicely And yet, both the binary logic software and the playback device following the script are completely unaware of what they are doing or why. In terms of consciousness, they are as dumb as a hammer. In other words, any "consciousness" in this is strictly limited to the author of the software and those who interpret the results. Otherwise, on it's own, it has no impact on reality. An ant comes way closer to exhibiting self awareness and consciousness.
- ben_w 4y agoWould you like to have a go at defining "consciousness"? ;)
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- jcims 4y ago(Thanks to fauigerzigerk for helping me post this to the right story on HN haha) The HN conversation yesterday about the complexity of the proton, in particular how we poke and prod at it to suss out its qualities and quantities, got me thinking about the subatomic particles of my personal subjective conscious experience. We can trace, with quite a bit of precision, how a certain photon cocktail results in me perceiving the orange title bar at the top of HN. But where's the orange paint in my brain? What is it made of and how could we inspect it like we inspect the guts of a proton? And furthermore, where's the camera that puts all of those particles of paint onto the same stage? We know where the visual cortex is, yes, but where's the camera that can see the whole stage at one time? That part, the integration of all of our perception into a single 'stage', is where I've long felt there has to be some kind of quantum or possibly field effect at play. Then I wondered if it might actually be possible for there to be an 'afterlife' of sorts in which the quantum relationship between particles is sustained beyond our life. Dunno. Trippy to think about though.
- simonh 4y agoYou might wonder in the same way how a digital camera stores information about colour, and processes that to identify a picture of a red apple. There are many ways to store and process information, and the same information can be encoded in many different ways. The computer stores and represents colour in an image file in one way, the neural net in an image classifier also stores it in a digital system but in a very different way. Our brains store it in yet another completely different way but also in a neural net. Yet all of these store the information that the apple is red. The point is the underlying substrate and encoding system doesn't matter, the information about the redness of the apple is correlated across all these systems, and it's that correlation that is meaningful. It seems unlikely that awareness is a quantum effect, because it manifests in brain activity across a significant part of the brain. The brain is too hot and chaotic, with too many constant low level interactions, to maintain a macroscopic entangled quantum state for significant time at that level without it decohering.
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- HarHarVeryFunny 4y agoThere are remarkably few things in the macroscopic world (I seem to recall that photosynthesis may use it?) that depend on quantum effects, and the ever growing extraordinary successes of ANNs proves the power of neural nets even in the most simple of classical functional approximations. It seems to me that trying to find macroscopic quantum effects in the brain is driven more by an illogical top down desire for them to be there, rather than a bottom up evidence-driven investigation of effects that can't be explained by classical physics/chemistry, of which none have been found in the brain.
- aikinai 4y agoFlash memory—something we use everyday now—relies on quantum tunnelling. I’m not sure if you consider that “macro,” but it affects our lives everyday and it blew me away when I first learned that it was an everyday application of effectively teleportation.
- colordrops 4y agoAre any of these AI neural nets working on computer equipment that doesn't use any quantum effects at all? Don't transistors also use quantum effects? It's not quantum computation, but we wouldn't be able to build at this scale if not for taking advantage of these phenomena.
- amelius 4y agoWithout QM, molecules would behave completely differently and the chair you're sitting on would probably fall apart into a pile of atoms. Everything depends on QM.
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- osigurdson 4y agoIf true, quantum computation at 37C/98F with no shielding is quite an incredible feat.
- osigurdson 4y agoEvolution has exploited many aspects of nature. It is counterintuitive in some ways that it would leave quantum computation off the table just because it is confusing to our ape brains.
- odyssey7 4y agoAgreed —- If there’s a way of leveraging it effectively, then evolution will do so, somewhere. My guess is that the brain isn’t unique from other tissues on this.
- mannykannot 4y ago> If there’s a way of leveraging it effectively... Those ways are quite heavily constrained by needing to start with what is already available, and for each step to be both heritable and reproductively advantageous.
- BoppreH 4y agoQuantum computing as we know it requires extreme isolation from the environment, usually in the form of vacuum, RF shielding, and extremely low temperatures. I'm skeptical of a wet warm mass achieving it. There are many aspects of nature that we have a good grasp on and evolution has failed to exploit, either at all or at non-insect scales. For example nuclear fission and fusion, neutrino detection, radioactivity, radio communication, superconductivity, and even some low-tech ones like chemical explosives, high speed projectiles, metalworking, cooking, lighter-than-air flight...
- gus_massa 4y agoI agree, very good list. I was just wondering about animals with a methane balloon. It doesn't look impossible. Fish has an air balloon to avoid going to the bottom, so a similar design may be possible.
- osigurdson 4y agoMetalworking and cooking aren’t exactly fundamental properties of nature.
- gus_massa 4y agoAs a general rule in the lab, when you find a nice signal you first check that it's not 50Hz (or 60Hz), because if the signal is too nice you are probably measuring the electric grid. They found a nice signal (Figure 1 in the paper) that correlates with the oxygen level in blood that is essentially the heartbeats. So my first assumption is that they are measuring noise instead of some deep consciousness property. Quantum effects are very important inside molecules, you can't calculate anything about them without QM (or an effective model). There are some quantum effects in slightly larger system, like photosynthesis https://en.wikipedia.org/wiki/Photosynthesis#Efficiency https://en.wikipedia.org/wiki/Photosynthesis#Efficiency but it's not a global effect or something that can solve complicated problems. It's just a very local, very short lived improvement, not something that can solve the TSP or think about the meaning of life. It's something in between of the intelligence of an electric switch for a lamp and a very cheap calculator. To get a global long lived quantum effect on a big system, you need very cold and very isolated systems. Otherwise, the noise breaks all the quantum correlation and you get a global classical system. Being very optimistic, perhaps they measured some very local and very short lived quantum effect. My biology is not strong enough, but perhaps some of the pores of the neurons use some quantum effect to open and close, for example to let sodium get in and out, or oxygen, or whatever. It's perfectly possible that cells use some short lived local quantum mechanics effect to improve some the efficiency of some living function, but it would be surprising that a neuron in the visual are in the back of your brain has an entangled electron with a neuron in the front of your brain that is thinking about the meaning of life. My proposal is to repeat the experiment with other organs, like the liver, the toes or whatever organ is the most stupid organ in your popular culture. If they are only measuring noise caused by some uninteresting quantum effect correlated with blood flow, I expect it to be also visible in other organs.
- singularity2001 4y agoEven without quantum effects there are quazillions of molecules in each neuron influencing learning and inference somehow. To what degree the neural architecture tries to void or use these interfering effects is a most interesting question.
- adamsmith143 4y agoPretty sure it's already been shown that no structures in the brain are small enough to have quantum effects and the brain is far too hot and noisy for anything useful to happen before decoherence.
- ki_ 4y agoI miss old science, the one where u needed proof and stuff. Anyway, anyone is free to do what they want in science, im just a bit fed up with the "thrust me bro" quantum science shared on HN almost daily.
- lisper 4y agoOriginal article: https://iopscience.iop.org/article/10.1088/2399-6528/ac94be/pdf https://iopscience.iop.org/article/10.1088/2399-6528/ac94be/...