Whole-brain connectome of the fruit fly • Hacker News Board

Re: Whole-brain connectome of the fruit fly

#81

Post by drdeca » Tue, Jul 04, 2023, 6:41 PM UTC

akomtu wrote: post #78

rbanffy wrote: post #46

Would instantiating this network and feeding it random inputs be akin to animal cruelty? Would you run tests on a cat connectome? A human’s? Yours?

Hardly so. A bunch of matrix multipliers is a fully deterministic system, a mechanism in other words. There is nothing in it that can experience pain. Using a truly random RNG device will simply "shake" this mechanism randomly. However with a feedback loop from the mechanism back to the RNG device things become murky, for now we can say that the radioactive rock behind the RNG might experience something, it may even…

What? Why would randomness matter to this?

If, hypothetically, it were possible to do a QFT simulation of an entire human, but where no true randomness was used in the simulation program, only a cryptographically secure (relative to an adversary with even more compute than the beyond-astronomical amount of compute used by the simulation) random number generator (and therefore fully deterministic),

you think that that would have less of a claim to having internal experience, than a simulation of a fruit fly brain connected to a true RNG?

This seems implausible to me.

Re: Whole-brain connectome of the fruit fly

#82

Post by elteto » Tue, Jul 04, 2023, 7:03 PM UTC

lhl wrote: post #4

Related: * Fruit Fly Brain Observatory https://www.fruitflybrain.org/#/posts/explore_ffbo which lets you visualize and explore datasets * Neurokernel http://neurokernel.github.io/ - open source software which "aims to build an open software platform for the emulation of the entire brain of the fruit fly Drosophila melanogaster on multiple Graphics Processing Units (GPUs)." See also: http://www.bionet.ee.columbia.edu/…

Very interesting!

A question from a layman: what is a “signal” in the context of a neuron? Is it discrete binary ON/OFF, or is it discrete with multiple levels, or is it fully analog? Do we know the “encoding” of the signals? What do they represent?

Re: Whole-brain connectome of the fruit fly

#83

Post by gwern » Tue, Jul 04, 2023, 7:06 PM UTC

mhb wrote: post #58

FrustratedMonky wrote: post #42

Didn't quite catch, is this just the first mapping, or are they able to 'execute it'. Like the worm project a few years ago. Where they mapped worm "C. elegans" brain, and was able to put in a simulated environment and watch reactions, and eventually into a robot body. This seems like next step up in complexity, so wondering how far they are along having the 'brain map' execute.

Whole Brain Emulation: No Progress on C. elegans After 10 Years https://www.lesswrong.com/posts/mHqQxwKuzZS69CXX5/whole-brai...

I'd highlight my comment there on recent progress since that was posted back in 2021: https://www.lesswrong.com/posts/mHqQxwKuzZS69CXX5/whole-brai...

Re: Whole-brain connectome of the fruit fly

#84

Post by elteto » Tue, Jul 04, 2023, 7:09 PM UTC

ouraf wrote: post #76

Ooh, i think i remember this one: It had the cosmic coincidence of one of its researchers being called Timothy MOSCA. https://www.smithsonianmag.com/smart-news/see-the-first-comp... good to see it got some more attention.

He was in charge of ethics.

Re: Whole-brain connectome of the fruit fly

#85

Post by oezi » Tue, Jul 04, 2023, 7:11 PM UTC

elteto wrote: post #82

lhl wrote: post #4

Related: * Fruit Fly Brain Observatory https://www.fruitflybrain.org/#/posts/explore_ffbo which lets you visualize and explore datasets * Neurokernel http://neurokernel.github.io/ - open source software which "aims to build an open software platform for the emulation of the entire brain of the fruit fly Drosophila melanogaster on multiple Graphics Processing Units (GPUs)." See also: http://www.bionet.ee.columbia.edu/…

Very interesting! A question from a layman: what is a “signal” in the context of a neuron? Is it discrete binary ON/OFF, or is it discrete with multiple levels, or is it fully analog? Do we know the “encoding” of the signals? What do they represent?

My understanding was that it is an analog signal of current. The voltage of which spikes when the Neuron fires. The signal travels along the dendrites and may boost or deactivate other neurons.

Re: Whole-brain connectome of the fruit fly

#86

Post by akomtu » Tue, Jul 04, 2023, 7:18 PM UTC

drdeca wrote: post #81

akomtu wrote: post #78

Earlier quoted context omitted.

Hardly so. A bunch of matrix multipliers is a fully deterministic system, a mechanism in other words. There is nothing in it that can experience pain. Using a truly random RNG device will simply "shake" this mechanism randomly. However with a feedback loop from the mechanism back to the RNG device things become murky, for now we can say that the radioactive rock behind the RNG might experience something, it may even…

What? Why would randomness matter to this? If, hypothetically, it were possible to do a QFT simulation of an entire human, but where no true randomness was used in the simulation program, only a cryptographically secure (relative to an adversary with even more compute than the beyond-astronomical amount of compute used by the simulation) random number generator (and therefore fully deterministic), you think that that…

That's right, it would have no internal experience. A giant deterministic calculator is just a mechanism that gives predictable outputs. It doesn't gain experience simply because it's superficially similar to a fruit fly or because it has so many transistors that we cannot count them.

If accurate simulation of a quatum system was possible within a deterministic 01 machine, we would have to declare that this is a dead world: a giant calculator that's moving gears in a deterministic manner.

A fruit fly does have internal experience, but its brains are based on a continuous system. With a deterministic machine we can approximate that continuous system with arbitrary, but finite, accuracy, and that approximation will be a dead calculator. Our computing paradigm - a deterministic turing machine - is simply unfit for replicating a continuous system, even though it can approximate it with sufficient (for science) precision. And yes, I believe that a quantum computer will be able to replicate a fruit fly well enough that we'll have to call that rwplica alive.

Edit. And let me address another dogma. A fruit fly, or a 10 neuron worm, doesn't exist in isolation like it's pictured in imagination of many computer scientists. The wave function is one for all particles, they all evolve as one intermingled system, so the moment you somehow isolate a fruit fly to make simulation tractable, it loses a good deal of what makes it a true fruit fly.

Re: Whole-brain connectome of the fruit fly

#87

Post by yieldcrv » Tue, Jul 04, 2023, 7:23 PM UTC

mr_toad wrote: post #57

soderfoo wrote: post #35

Visual processing requires an astounding amount of brain power. Over 50% of a fruit flies brain cells are dedicated to their rudimentary visual system. Comparatively, the human visual processing system is truly astonishing and I am grateful for it.

They’re doing a more complex job than a self driving car, with a pinhead sized brain, miniature sensors, and less power than a set of AirPods.

Battery dies in the same amount of time so I wouldn’t consider this a technical feat.

Re: Whole-brain connectome of the fruit fly

#88

Post by shawnz » Tue, Jul 04, 2023, 7:29 PM UTC

akomtu wrote: post #86

drdeca wrote: post #81

Earlier quoted context omitted.

What? Why would randomness matter to this? If, hypothetically, it were possible to do a QFT simulation of an entire human, but where no true randomness was used in the simulation program, only a cryptographically secure (relative to an adversary with even more compute than the beyond-astronomical amount of compute used by the simulation) random number generator (and therefore fully deterministic), you think that that…

That's right, it would have no internal experience. A giant deterministic calculator is just a mechanism that gives predictable outputs. It doesn't gain experience simply because it's superficially similar to a fruit fly or because it has so many transistors that we cannot count them. If accurate simulation of a quatum system was possible within a deterministic 01 machine, we would have to declare that this is a dead…

I don't see any reason why determinism should have anything to do with conscious experience.

Can't you conceive of a deterministic universe in which you have internal experience just like you do now? What specifically makes those two things mutually exclusive in your opinion?

Re: Whole-brain connectome of the fruit fly

#89

Post by empyrrhicist » Tue, Jul 04, 2023, 7:34 PM UTC

luckystarr wrote: post #59

empyrrhicist wrote: post #41

Earlier quoted context omitted.

Unfortunately, there's a good chance you have fungus gnats and not fruit flies. Do they live in houseplants? In my experience fruit flies go away if you rinse cans/bottles, and keep the sinks/drain clean, and use a lid for your compost.

I had some sort of gnat living in the soil of my plants. After I subjectively tried every chemical known to mankind, I got rid of them by ordering a package of egg- or larvae-eating nematodes over the net, mixing them with water and sprinkling them in. Instant success.

The nematodes have helped me, but not eliminated them. I have a lot of plants.

Re: Whole-brain connectome of the fruit fly

#90

Post by akomtu » Tue, Jul 04, 2023, 7:58 PM UTC

shawnz wrote: post #88

akomtu wrote: post #86

Earlier quoted context omitted.

That's right, it would have no internal experience. A giant deterministic calculator is just a mechanism that gives predictable outputs. It doesn't gain experience simply because it's superficially similar to a fruit fly or because it has so many transistors that we cannot count them. If accurate simulation of a quatum system was possible within a deterministic 01 machine, we would have to declare that this is a dead…

I don't see any reason why determinism should have anything to do with conscious experience. Can't you conceive of a deterministic universe in which you have internal experience just like you do now? What specifically makes those two things mutually exclusive in your opinion?

That's the crux of the matter. Conscious experience cannot exist in determinstic worlds. In finite sized worlds, such as calculators, any deterministic algorithm is equivalent to a giant lookup table: (input, memory) -> (output, memory), all four entities have a finite fixed size. For infinitely expanding deyerministic worlds it's more complicated, but it's obvious that such worlds have to expand at the expense of some outer realm, as you cannot create more GBs of memory out of thin air.

This problem with determinism has a theological angle (I've warned you). The so called "fallen angel" believed that consciousness can exist in deterministic worlds, and he had an impressive design of such a place. That world was created, but his vision never materialised: his mind was vast enough to imagine such a world, but not enough to see its subtle deficiency.