12 ms·
Cerebrum: Simulate and infer synaptic connectivity in large-scale brain networks
- HL33tibCe7 2y agoQuestion: would such a simulation be conscious? If not, why not?
- jncfhnb 2y agoAlso, would it be quorled?
- fellerts 2y agoWhat now?
- jncfhnb 2y agoPrecisely
- GlenTheMachine 2y agoThis, exactly. Nobody can defined what consciousness is in terms that can be experimentally validated. Until that happens not only can the question not be answered, it isn't even a question that makes any sense.
- bqmjjx0kac 2y agoThere are more questions that make sense than those that can be tested. To the point, I have a convincing experience of consciousness and free will — qualia — and I suspect a digital clone of my brain would have a similar experience. Although this question is not testable, I think it's inaccurate to say that it doesn't make sense.
- jncfhnb 2y agoIt’s not really the testableness that makes the problem. It’s the fact that you’re asking about X where X is undefined. If you can provide a satisfying definition of X it’s very clear
- kelseyfrog 2y agoHow would you operationalize quorledness?
- Vampiero 2y agoAnswer: no one knows how consciousness works
- fallingknife 2y agoIf you accept the two premises: 1. A human brain has consciousness 2. The device is a perfect digital replica of a human brain I can't think of any argument that the device does not have consciousness that doesn't either rely on basically magic or lead to other ridiculous conclusions.
- Vampiero 2y agoThe argument is that if you accept your precondition then you must also accept superdeterminism and that free will does not exist. Because physicalism implies that the mind is an emergent phenomenon, and because quantum physics is a linear theory, there's simply no place for free will unless you go down some weird/unfalsifiable rabbit holes like the MWI. So a lot of people prefer to latch onto the idea that there is a soul, because if there wasn't one, then they wouldn't be special anymore.
- webmaven 2y ago> there's simply no place for free will unless you go down some weird/unfalsifiable rabbit holes like the MWI. I don't follow. Quantum mechanics means that physics is stochastic, and only approximates classical determinism in aggregate. Meanwhile, brains seem to operate in a critical state that can be tipped to different phase transitions by small perturbations, so there is potential for a quantum event to influence the brain as a whole in a nondeterministic fashion. This means that strict physicalism still leaves the door open to our behavior being stochastic rather than deterministic, doesn't it?
- Vampiero 2y agoQuantum events may be stochastic (there's still some hope for hidden variables though from what I understand -- either way, as far as the macroscopic world is concerned, it's basically random) but that doesn't mean that somewhere in that randomness a cosmic YOU is deciding anything. It just means it's random. Anything that follows after that is perfectly causal and determined and can be understood in the context of chaos theory. So in this view consciousness is better explained as an illusion than as the seat of your will. Because you can't really have a will if every interaction that led to your existence can, in principle, be computed forward in time from the big bang. Physicalists see it as a complex emergent phenomenon akin to a run of Conway's Game of Life that started from a random seed.
- namero999 2y agoOf course not. A simulation is not the process itself. So even provisionally granting that consciousness is magically created by the brain (for which we have no evidence), a computer simulation would still not be a brain and therefore not create consciousness. You would not expect your computer to pee on your desk if you were to simulate kidney function, would you?
- lucasoshiro 2y ago> You would not expect your computer to pee on your desk if you were to simulate kidney function If my computer is connected to actuators that opens a pee valve like a brain is, then I expect. The main point, in think, is that we can't say precisely what consciousness is. Everything definition on that that I can imagine is something that can be replicated in a computer or that relies on belief, like the existence of a soul... I hope that we have answers for that before the technology that allow us to do that
- IAmYourDensity 2y ago> A simulation is not the process itself. Sometimes a simulation IS the thing. A simulation of a wall clock IS a functioning clock (e.g. the clock icon on our smartphones). An autopilot that can takeoff, fly, and land an airplane IS a pilot. Chess engines that can beat grandmasters are chess players. A computer simulation of a teacher that can educate students is a teacher. Sometimes these simulations lack some of the capabilities of their human counterparts, and sometimes they far exceed them. > You would not expect your computer to pee on your desk if you were to simulate kidney function, would you? You would not reject a computer-controlled dialysis machine as "just a simulation" if you had kidney failure would you?
- namero999 2y ago> You would not reject a computer-controlled dialysis machine as "just a simulation" if you had kidney failure would you? Except that's not a simulation, that's the actual process of dialysis in action (which we fully understand, contrary to consciousness). And coincidentally, a dialysis machine _does not_ look like a kidney, not even remotely, and any homomorphism one can point to, is such only through a great deal of layers of abstraction. I would totally reject a simulation of a kidney. We are talking about a computer simulation like a neural network. We detect topological relationships in neurons and we are led to believe or entertain the possibility that all there is to it is such topological description, hence any substrate will do. This is completely arbitrary and leads to all sort of phantasies such as "qualities emerge from quantities" and "a simulation of a brain behaves like a brain". A computer simulation of a kidney won't produce urine just like a simulation of a brain won't produce whatever the brain produces, if anything. Now, to build on your dialysis machine analogy, if we were to understand how consciousness work, and if we were to understand what relationships it holds with the brain and the body, then I submit that anything artificial we will produce will look like biology.
- geor9e 2y agoJust like the thousands of times this has been asked in the last century of sci-fi novels, the answer to such semantic questions depends on the mood of the audience for how approximate of a copy they need the ship of Theseus to be before they're comfortable using a certain word for it.
- bossyTeacher 2y agoBit hard to answer that since there is no definition of consciousness, is there? If I gave you access to the brain of some living animal, you wouldn't be able to tell whether it was "conscious" would you? Not sure, how can we expect that from an artificial and highly simplified version of a neural network
- aithrowawaycomm 2y agoThe real problem is that this uses a very a crude and inadequate model for neurons: it ignores neurotransmitters, epigentics, or the dendritic complexity of cortical neurons. There’s no chance this system will ever come close to simulating an actual brain.
- RaftPeople 2y agoAnd it ignores that neurons are dynamically inhibited/excited by the astrocytes at the synapse. The network itself is shifting constantly as it processes information.
- jncfhnb 2y agoI feel like these kinds of things are misguided. Our “minds” are not, for lack of a better term, Chinese rooms operating on external stimulus. Our minds aren’t just brains, they’re deeply tied to our bodily state and influenced by hormonal mechanics that many different organs besides the brain control. It’s kind of romantic to say we could digitally replicate a brain in isolation, but our minds are messy and tangled. We might tend to think of these modifiers, like being hangry or horny, as deviations from a “normal”, but frankly I doubt it. I would wager these dynamics actually control the majority of our “minds” and the brain is just encoding/decoding hardware.
- fallingknife 2y agoIf you can digitally replicate a brain, you can also digitally replicate all those input signals.
- jncfhnb 2y agoIn the sense that you can write any writeable program, sure. But that doesn’t mean there’s an obvious path to do so. The brain is a part of a much larger system. We don’t really have a clue how to model these things, even theoretically. It’s vastly more complex than neurons.
- robwwilliams 2y agoNot yet. It is a serious error to think of action potentials as the relevant variable of cognition. The real action is subthreshold ionic currents, neuromodulatory tone, and even the big mess of cytosilic, mitochondrial, and nuclear metabolism. The CNS is a hugely complex analog computation matrix that only uses action potentials for INTRAcellulat communication. Everything between cells is comparatively subtle ionic and chemical flux. Modeling at this level may be practical in retina at some point but modeling the entire CNS for pragmatic gains for Alzheimer’s disease research is not going to work. And embodiment is critical. The brain is not a Cartesian input-to-output machine. It is almost the opposite. See the “enactivist” philosophy of cognition (Noe, Velera, Maturana). (I also worked on the EU Human Brain Project with Markram and others; also on several similar NIH programs. )
- 2y ago
- dfgtyu65r 2y agoSo, if I understand correctly they're using Hodgkin-Huxley LIF neurons but trained end-to-end in a graph neural network. Through training to reproduce the neural data, the network learns the underlying connectivity of the neural system? This seems very cool, but I'm surprised this kind of thing attracts VC money! I'm also skeptical how well this would scale due to the inherently underdetermined nature of neural recordings, but I've only skimmed the PDF so may be missing their goals and approach.
- kelseyfrog 2y agoThere's much better brains to recreate than mine. Shit's broken.
- dang 2y agoWe've taken your brain out of the title now (no offense). (Submitted title was "Cerebrum: What if we could recreate your brain?")
- RaftPeople 2y ago> "Cerebrum: What if we could recreate your brain?" Can you ask it where my keys are?
- seany62 2y agoBased on my very limited knowledge of how current "AI" systems work, this is the much better approach to achieving true AI. We've only modeled one small aspect of the human (the neuron) and brute forced it to work. It takes an LLM millions of examples to learn what a human can in a couple of minutes--then how are we even "close" to achieving AGI? Should we not mimic our biology as closely as possible rather than trying to model how we __think__ it works (i.e. chain of thought, etc.). This is how neural networks got started, right? Recreate something nature has taken millions of years developing and see what happens. This stuff is so interesting.
- etrautmann 2y agoThere’s currently an enormous gulf in between modeling biology and AGI, to the point where it’s not even clear exactly where one should start. Lots of things should indeed be tried, but it’s not obvious what could lead to impact right now.
- idiotsecant 2y agoGreat, let's do that. So how does consciousness work again, biologically?
- lostmsu 2y ago> It takes an LLM millions of examples to learn what a human can in a couple of minutes LLMs learn more than humans learn in a lifetime in under 2 years. I don't know why people keep repeating this "couple of minutes". Humans win on neither the data volume to learn something nor the time. How much time do you need to learn lyrics of a song? How much time do you think a LLaMA 3.1 8B on a 2x3090 need? What if you need to remember it tomorrow?
- marmaduke 2y agohaving worked on whole brain modeling the last 15 years and european infra for supporting this kinda research, this is a terrible buzzword salad. the pdf is on par with a typical masters project.
- nynx 2y agoyeah, i did my undergrad research on biological neuron emulation and most of the research in the area is hilariously moronic things just for pumping "research" out and getting students their pieces of paper.
- rrr_oh_man 2y agohttps://github.com/the-virtual-brain https://github.com/the-virtual-brain This looks cool!
- SubiculumCode 2y agoI'm a bit confused at what this is actually. Is it a modeling framework that you use to build and study a network? Is it a system that you use to help you analyze your neural recording datasets? Neuroscience is a big place, so I feel like maybe the article and technical paper is speaking to a different audience than me, a neuroimager.
- fschuett 2y agoSimulating a brain would mean that reason, the ability to discern good from bad, is a statistical process. All scientific evidence so far shows that this is not the case, since AIs do not have the ability to "understand" what they're doing, their input data has to be classified first to be usable to the machine. Especially the problem of model collapse shows this, when an AI is trained on the output of another AI, trained on the output of another AI, it will eventually produce garbage, why? Because it doesn't "understand" what it's doing, it just matches patterns. The only way to correct it is with hundreds or even thousands of employees that give meaning to the data to guide the model. Consciousness presumes the ability of making conscious decisions, especially the ability to have introspection and more importantly, free will (otherwise the decision would not be conscious, but robotic regurgitation), to reflect and to judge on the "goodness" or "badness" of decisions, the "morality". Since it is evident that humans do not always do the logical best thing (look around you how many people make garbage decisions), a machine can never function like a human can, it can never have opinions (that aren't pre-trained input), as it makes no distinction between good and bad without external input. A machine has no free will, which is a requirement for consciousness. At best, it can be a good faksimile. It can be useful, yes, but it cannot make conscious decisions. The created cannot be bigger than the creator in terms of informational content, otherwise you'd create a supernatural "ghost" in the machine. I hope I don't have to explain why I consider creating ghosts unachievable. Even with photo or video AIs, there is no "new" content, just rehashed old content which is a subset of the trained data (why AI-generated photos often have this kind of "smooth" look to them). The only reason the output of AI has any meaning to us is because we give it meaning, not the computer. So, before wasting millions of compute hours on this project, I'd first try to hire and indebted millennial who will be glad to finally put his philosophy degree to good use.
- kelseyfrog 2y agoConsciouness of the gaps. Labeling ourselves as the most intelligent species has done irreparable psychic damage.
- eMPee584 2y agoThis describes the current situation, but what about if models become self-learning and dynamic both in content (weights) as in structure / architecture? what changes if these digital systems are combined with biological neuronal networks and quantum processors? It seems too early to rule out a possibility of emergence of consciousness from machines.. beings, yet uncreated..
- jmyeet 2y agoFun fact: neurons are kept electrically negative or, more specifically, the resting membrane poential is negative [1]. It does this with a mechanism that exchange sodium and potassium ions, a process that uses approximately 10% of the body's entire energy budget [2]. I think it'll be incredibly difficult simulate a neuron in a meaningful way because neurons, like any cell, are a protein soup. They're exchanging ions. those ions will affect the cell. The neuron's connections grow and change. [1]: https://www.khanacademy.org/science/biology/human-biology/neuron-nervous-system/a/the-membrane-potential https://www.khanacademy.org/science/biology/human-biology/ne... [2]: https://bionumbers.hms.harvard.edu/bionumber.aspx?id=103545&ver=0 https://bionumbers.hms.harvard.edu/bionumber.aspx?id=103545&...
- nynx 2y agoBiologically inspired neuron models like Hodgkin–Huxley are about as far from an emulation of real neuron behavior as a paper airplane is from the space shuttle. We can learn things from using them and they're an important stepping stone, but they aren't really that useful. That being said, I hope the founder keeps it up — it's great to have more bright, driven people in this field.
- stevenhuang 2y agoI wouldn't be so certain. After all it is unknown to the extent each unique biological aspect of the neuron actually matters to the function of the brain and mind. If it turns out it is the higher order network effects that are more important, then these lower level "implementation details" will be of practical insignificance.
- RaftPeople 2y ago> I wouldn't be so certain. After all it is unknown to the extent each unique biological aspect of the neuron actually matters to the function of the brain and mind. We know that some neurons learn in isolation (purkinje cells). Meaning that it learns and detects patterns of sequences of input, and produces output based on that (e.g. trigger blinking in rabbit eye). It seems like this one item alone indicates that the HH model is limited.
- johnea 2y agoThis can only work because most people's brains are very very small...