[HN Gopher] Map of an Insect's Brain ___________________________________________________________________ Map of an Insect's Brain Author : mkmk Score : 139 points Date : 2023-03-11 18:56 UTC (4 hours ago) (HTM) web link (www.smithsonianmag.com) (TXT) w3m dump (www.smithsonianmag.com) | FrustratedMonky wrote: | if you map every single neuron, at what point is it no longer | just a 'model' of reality, and is reality. How do we know that | the computer model of neurons does not have the same internal | awareness as the real neurons? | notfed wrote: | In this case the "map" is simply a set of high-res images, not | a computer model. I don't think an image can be aware. | FrustratedMonky wrote: | Guess I need to find source study. This high level article | makes it sound like an actual map, not an image. Based on | same type of map that has been made of nematode | | From article Now, researchers have constructed a detailed map | of the neurons and the connections between them in the brain | of a larval fruit fly. With 3,016 neurons and 548,000 | connections, called synapses | notfed wrote: | There's no citation, but I am assuming it's this: | | "A searchable image resource of Drosophila GAL4-driver | expression patterns with single neuron resolution. eLife, | 2023; 12 DOI: 10.7554/eLife.80660" | FrustratedMonky wrote: | This article overstates it. This mapping is not as detailed | as what was done with The nematode worm Caenorhabditis | elegans. Where they did entire nervous system. | lossolo wrote: | > if you map every single neuron, at what point is it no longer | just a 'model' of reality, and is reality | | If you map position of every fish in the sea will you have a | model of a living sea with living fish and all their | interactions (electrical/physics/chemical etc)? Or just the | positions of fish in a sea at certain point of time? | causality0 wrote: | That would require knowledge of how detailed you have to get | before going deeper stops altering the performance. I suspect | there is no magic line that becomes sapience once you cross it; | there's just a smooth slope upwards. Someday we'll have to | decide standards of measurement that separate the living from | the dead. | wizofaus wrote: | Is there convincing evidence actual insects have "awareness"? | otabdeveloper4 wrote: | What is "awareness"? | | The only objective, measurable quantity is information | complexity. (And yes, insects have it.) | [deleted] | object-object wrote: | If you map every single class in UML, at what point is it no | longer just a 'model' of the software, and is the software. | layer8 wrote: | Neurons have a huge internal complexity and diversity, and this | connectome doesn't tell you much about those internals. | GordonS wrote: | > The connectome of the larval fly, published Friday in the | journal Science, took 12 years to complete. Imaging a single | neuron required about a day... | | > Human brains have an estimated 86 billion neurons and hundreds | of trillions of synapses... | | So, the techniques used for the fly are totally impractical for | humans, or presumably any mammal. Anyone know of any developments | that may help? Maybe AI could be used to automate processing of | the images? | inportb wrote: | More like totally impractical for living specimens that you | want to continue living meaningfully. | kuprel wrote: | "If the human brain were so simple that we could understand it, | we would be so simple that we couldn't." | | Maybe AI can though | notfed wrote: | Asking AI to map human brains...what could possibly go wrong? | dredog wrote: | Yep, this is already happening. I think it's called 'automatic | segmentation'. | undersuit wrote: | Do we need to image all 86 billion? A sampling of cells | throughout the brain and a simulation of a cell such that we | can figure out how 1 fertilized egg can become 86 billion | neurons _and change_. We can throw compute power at that, we | don 't really have brains to throw at the problem. | caxco93 wrote: | It kinda looks like the balloons in the Up movie | causality0 wrote: | _With 3,016 neurons and 548,000 connections, called synapses, the | result is by far the most complex map of a whole brain ever | made._ | | It's an impressive achievement but I'm not sure I'd call that a | whole brain. It's a larval proto-brain with less than 4% the | neurons of an adult fly. | xipho wrote: | Science and Nature are the canonical exaggerators when it comes | to headlines. Whole genome, whole mitochondria, complete, | total, you name it, there is (nearly?) always an invisible | asterisk at the end. When these words are use then Materials | and Methods tell you what actually happened. | | What's completely crazy in this research is the ability to | thin-section fly brains. Thousands and thousands of slices _of | a fly brain_, good old physical science at the heart, crowd- | sourced to connect the dots (though I'm not positive that's the | case in this paper). The open-hardware imaging tools used in | some studies like this are also super cool- | https://openspim.org/. | ralusek wrote: | His name is Timothy Mosca and he works with fruit flies... | | Mosca means fly, the insect, in Spanish. | usgroup wrote: | i intuitively think that there is something similar in kind | between a fruit fly brain and a human brain regardless of the | scale, and that cracking the smaller case will somehow lead to | cracking the larger one. However, rather than hope, it leads me | to a negative conclusion. That is, even at orders of magnitude | smaller scales, and with full knowledge of how all the gross bits | are connected, we still won't be able to understand what actually | happens and why it works. | | I suspect this will be the case because the old microscopic will | become the new macroscopic and we will realise that there is yet | orders of magnitude more details to make sense of. | scarmig wrote: | > But the study revealed that a third of the connections in the | fruit fly's brain did not follow this pattern--they were between | two axons, between two dendrites or from a dendrite to an axon. | | Interesting. Does this extend to humans? Does it offer a | plausible biological mechanism for backprop? | abraxas wrote: | Is it simulated to the level where you could give it some visual | stimulus and observe the actions it is trying to take? Could it | be wired to a remote robotic insect and control it in real time? | | I've no idea how detailed these simulation projects and if we are | months or decades away from doing what I mentioned | ar9av wrote: | The level of detail in insect brain simulations varies, and it | may be challenging to simulate it to the level of reacting to | visual stimuli. Neural interfaces have been successful in | controlling robots, but real-time processing and precision | remain a challenge. | gptgpp wrote: | Man... I just find neural connectomes so depressing. | | It's like looking at the copper wiring on the motherboard, or | the pins of the CPU, when what you really want is the logic | from the networked gates (transistors). | | Yet it seems we are many, many decades away from being able to | extract that in any comprehensible or definitive way. | | I need to stop reading neuroscience articles. There's always | big proclamations, Like "the neural circuitry behind arithmetic | has been discovered!" then you dig into the meat and it's | mostly guesswork and hypothesis based on correlated activity | and connectivity, no logic to be seen. | | This paper did blow my mind though, I hope to see more creative | stuff like it: | | https://www.cell.com/neuron/fulltext/S0896-6273(22)00806-6?_... | | pdf here: | | https://www.cell.com/action/showPdf?pii=S0896-6273%2822%2900... | kelseyfrog wrote: | Idk, I think it's like looking at a winning lottery ticket[1] | to a game you haven't played yet. | | 1. https://arxiv.org/abs/1803.03635 | seesawtron wrote: | You should read about the immense criticism this paper | attracted after its publication. It was published on the same | journal since publishers like a bit of controversy ;) [0] htt | ps://www.sciencedirect.com/science/article/abs/pii/S08966... | gptgpp wrote: | There's a pdf here if anyone else is interested: | | https://www.yorku.ca/science/research/schalljd/wp- | content/up... | | Yeah all that criticism doesn't go into any detail about | actual methodological flaws or issues with the results... | It just complains about language and is pretty | sanctimonious for such weak and generic citations. Like, | those are the sort of citations I'd give as an undergrad | and trying to pad a paper to make it seem more | authoritative and well established than it is lol. | | Were any of the criticisms NOT centered around their | irresponsible use of language and about the actual | methodology and results? How they cultured different | neurons to play pong is pretty amazing by itself to me. | hprotagonist wrote: | > It's like looking at the copper wiring on the motherboard, | or the pins of the CPU, when what you really want is the | logic from the networked gates (transistors). | | and what you kind of _really_ want is a debugging guide to an | OS. | | hah hah it is to laugh. | yyyk wrote: | >Is it simulated to the level where you could give it some | visual stimulus and observe the actions it is trying to take? | | No way. | | First, this mapping doesn't tell us how the synapses are | regulated - if we could 'run' this the weights would stay fixed | forever and that's not how a brain works. | | Second, there must be some neurons dedicated to chemical | management, and they'd go haywire unless you found a way to | deal with them. It's possible the hardware/software is so | intertwined it can't be separated. Or maybe it's just complex, | regardless the mapping is of limited use here. | | Third, you're assuming that the synapses/axons are the only | thing that matters. It may well be this is true, but having | other processes being involved has not yet been entirely ruled | out. If they are, the mapping is incomplete. | | Lastly, we don't have the computational ability just yet to | simulate even the mapping itself. | falcor84 wrote: | >Lastly, we don't have the computational ability just yet to | simulate even the mapping itself. | | Could you please explain why not? 548,000 synapses sounds | entirely feasible to me. | margorczynski wrote: | Wasn't there success in replicating how the neuron | modulates a signal with electronics? If we can reproduce | the out given any in then that's interchangeable from a | system perspective? | yyyk wrote: | Neurons and synapses are incredibly complex. Think you're | emulating over 3,000 heterogeneous cores with over half a | million links while communication must be low-latency-ish. | A third of the links seem to join other links and we don't | even know what that does. If there's computation there | we'll need even more cores. | aperrien wrote: | I think you may be overestimating the complexity. The | better idea is to set up and experiment with different | simulation parameters, and see how far they diverge from | actual observed behavior. | coldtea wrote: | I think you underestimating the problem. There's no way | to even capture and record "observed behavior" at the | required level atm... | xyproto wrote: | It could be simulated slowly at first. | lossolo wrote: | To simulate something you need to first know how it works | and know all the relevant interactions, this is something | that we currently do not understand. Neurons are not | equivalent of neural networks we use in computers, they | are A LOT more complex with whole groups firing the same | time and chemicals regulating neurons all the time and | whole topology is plastic, it works in a way we can't | model or simulate currently. People hugely overestimate | our knowledge about brains. | coldtea wrote: | That requires we know how each node behaves and the kind | of inputs it has, which we're very very far off from... | neurohdmi wrote: | The first thing you said is correct. To do a proper | simulation you would need to gather functional properties of | the various cell classes and their synaptic connection, which | this study didn't do. (Maybe you can find that information | from other lab, I'm not familiar with fly models?) | | However we definitely have the computational ability to do | simulations a fly network. Look at some of the modeling done | by the Blue Brain Project or Allen Institute for Brain | Science - they do simulations of rat and mice models with | hundreds-of-thousands to millions of neurons and | exponentially more synapses. 3000 neurons is not that many. | If you stuck to non-compartmental point models a 3,000 neuron | simulation could probably be ran on a moderately high-end | laptop. | | But as said before, the physical connectome is only part of | the information you'd need do any worthwhile simulations. | Groxx wrote: | For some more context / concrete links: there are ongoing | efforts to simulate the C. elegans worm, e.g. | https://openworm.org/ , which has ~300 neurons. | | The _actual precision_ of this model is: nobody knows, | because nobody knows _precisely_ what neurons do / what they | react to. We know some of it but definitely not all. But, | simulating what we _do_ know, you get quite worm-like | behavior, despite whatever flaws exist. | | To get a more perfect simulation, we'd need more perfect | knowledge of the chemistry and physics, and lots and lots | more computing power. It's something that's continually | improving, but a lot of shortcuts have to be made to make it | even _remotely_ calculable. | moffkalast wrote: | Not sure if they're at that stage yet, but it's definitely | possible and been done before for the elegans worm | https://github.com/topics/c-elegans | | They even got a web sim working by now it looks like | https://heyseth.github.io/worm-sim/ | notfed wrote: | This article is fluffy. The original research is titled: | | "A searchable image resource of Drosophila GAL4-driver | expression patterns with single neuron resolution. eLife, 2023; | 12 DOI: 10.7554/eLife.80660" | nawgz wrote: | "With 3,016 neurons and 548,000 connections, called synapses, the | result is by far the most complex map of a whole brain ever | made." | | "Researchers have also mapped 25,000 neurons and 20 million | synapses in the brain of an adult fruit fly, but this is still | just a partial [map]" | | "Human brains have an estimated 86 billion neurons and hundreds | of trillions of synapses" | | The scales at play here are hard to imagine. This is very | interesting but it seems the most interesting facet is the | completeness, and not just the absolute scale. | penny10k wrote: | [dead] | jokoon wrote: | I wish AI scientists would try to work on this instead of machine | learning. | jll29 wrote: | Machine learning has much more humble goals: fitting a bunch of | data to a curve. | | Despite all the hype around chatGPT, I have yet to see any | model that asks me a question (without being programmed to do | so). Today, my son asked me out of the blue: "Why do people | write on paper?" and "What are our walls made of?" and "Why | don't we paint our house yellow?". I don't care to live | extraordinarily long, but I'd give my right arm to have a quick | peek into the future just to see how much of the brain's | underlying mysteries will be decoded in, say, 100 or 1,000 | years. | seesawtron wrote: | But they are: https://research.google/teams/connectomics/ | DonHopkins wrote: | In Jaron Lanier's review of John Markoff's book "What the | Dormouse Said", he mentioned an exchange between Douglass | Engelbart and Marvin Minsky: | | https://web.archive.org/web/20110312232514/https://www.ameri... | | >Engelbart once told me a story that illustrates the conflict | succinctly. He met Marvin Minsky -- one of the founders of the | field of AI -- and Minsky told him how the AI lab would create | intelligent machines. Engelbart replied, "You're going to do | all that for the machines? What are you going to do for the | people?" This conflict between machine- and human-centered | design continues to this day. | simonh wrote: | You really believe we'd be better off doing no machine learning | research at all? | coldtea wrote: | Machine learning? We'd be better off with way less technology | in general... if we manage to survive tech induced climate | change and/or potential nuclear annihilation without billions | dying that is... | teabee89 wrote: | Numenta tries to do something like that: reverse engineer the | neocortex (so not a fly's brain). It does have some insights | but I think it's still a long way. ___________________________________________________________________ (page generated 2023-03-11 23:00 UTC)