[HN Gopher] Map of an Insect's Brain
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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.
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