zlacker

[parent] [thread] 39 comments
1. teuobk+(OP)[view] [source] 2024-05-09 22:12:13
The interactive visualization is pretty great. Try zooming in on the slices and then scrolling up or down through the layers. Also try zooming in on the 3D model. Notice how hovering over any part of a neuron highlights all parts of that neuron:

http://h01-dot-neuroglancer-demo.appspot.com/#!gs://h01-rele...

replies(3): >>jamiek+F2 >>gofred+pc2 >>oniony+LB2
2. jamiek+F2[view] [source] 2024-05-09 22:34:12
>>teuobk+(OP)
My god. That is stunning.

To think that’s one single millimeter of our brain and look at all those connections.

Now I understand why crows can be so smart walnut sized brain be damned.

What an amazing thing brains are.

Possibly the most complex things in the universe.

Is it complex enough to understand itself though? Is that logically even possible?

replies(6): >>ignora+I3 >>nickle+e4 >>layer8+zc >>m3kw9+td4 >>robgib+dv4 >>wg0+2d6
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3. ignora+I3[view] [source] [discussion] 2024-05-09 22:42:17
>>jamiek+F2
I wonder if we manage to annotate this much level of detail about our brain, and then let (some variant of the current) models train on it, will those intrinsically end up generalizing a model for intelligence?
replies(1): >>nickle+s4
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4. nickle+e4[view] [source] [discussion] 2024-05-09 22:46:06
>>jamiek+F2
Crow/parrot brains are tiny but in terms of neuron count they are twice as dense as primate brains (including ours): https://www.sciencedirect.com/science/article/pii/S096098221...

If someone did this experiment with a crow brain I imagine it would look “twice as complex” (whatever that might mean). 250 million years of evolution separates mammals from birds.

replies(6): >>jamiek+X5 >>Terr_+08 >>pfdiet+Ke >>steve_+Dj >>LargoL+ss >>djmips+2M2
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5. nickle+s4[view] [source] [discussion] 2024-05-09 22:48:48
>>ignora+I3
I think you would also need the epigenetic side, which is very poorly understood: https://www.universityofcalifornia.edu/news/biologists-trans...

We have more detail than this about the C. elegans nematode brain, yet we still no clue how nematode intelligence actually works.

replies(1): >>Animat+Z6
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6. jamiek+X5[view] [source] [discussion] 2024-05-09 23:06:17
>>nickle+e4
Interesting! Thank you. I didn’t know that.
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7. Animat+Z6[view] [source] [discussion] 2024-05-09 23:18:59
>>nickle+s4
How's OpenWorm coming along?
replies(1): >>nickle+7O1
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8. Terr_+08[view] [source] [discussion] 2024-05-09 23:25:44
>>nickle+e4
I expect we'll find that it's all a matter of tradeoffs in terms of count vs size/complexity... kind of like how the "spoken data rate" of various human languages seems to be the same even though some have complicated big words versus more smaller ones etc.
replies(1): >>sdento+Pk
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9. layer8+zc[view] [source] [discussion] 2024-05-10 00:08:37
>>jamiek+F2
We don’t know what “understanding” means (we don’t have a workable definition of it), so your question cannot be answered.
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10. pfdiet+Ke[view] [source] [discussion] 2024-05-10 00:33:06
>>nickle+e4
That shouldn't be too surprising, as a larger fraction of the volume of a brain should be taken up by "wiring" as the size of the brain expands.
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11. steve_+Dj[view] [source] [discussion] 2024-05-10 01:24:42
>>nickle+e4
This might be a dumb question, because I doubt the distances between neurons makes a meaningful distance… But could a small brain, dense with neurons like a crow, possibly lead to a difference in things like response to stimuli or “compute” speed so to speak?
replies(5): >>michae+1q >>out_of+1E >>philsn+ag3 >>tlarkw+6F3 >>JKCalh+IG3
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12. sdento+Pk[view] [source] [discussion] 2024-05-10 01:39:31
>>Terr_+08
Birds are under a different set of constraints than non-bat mammals, of course... They're very different. Songbirds have ~4x finer time Perception of audio than humans do, for example, which is exemplified by taking complex sparrow songs and showing them down until you can actually hear the fine structure.

The human 'spoken data rate' is likely due to average processing rates in our common hardware. Birds have a different architecture.

replies(1): >>Terr_+7v
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13. michae+1q[view] [source] [discussion] 2024-05-10 02:55:03
>>steve_+Dj
Actually I think that's pretty plausible. Signal speed in the brain is pretty slow - it would have to make some difference
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14. LargoL+ss[view] [source] [discussion] 2024-05-10 03:23:19
>>nickle+e4
IIRC bird brains are 'packed/structured' very similar to our cerebellum.

So one would just need to pick that little cube out of our cerebellum, to have that 'twice as complexity'.

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15. Terr_+7v[view] [source] [discussion] 2024-05-10 03:53:26
>>sdento+Pk
You misunderstand, I'm not making any kind of direct connection between human speech and bird song.

I'm saying we will probably discover that the "overall performance" of different vertebrate neural setups are clustered pretty closely, even when the neurons are arranged rather differently.

Human speech is just an example of another kind of performance-clustering, which occurs for similar metaphysical reasons between competing, evolving, related alternatives.

replies(1): >>sdento+S53
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16. out_of+1E[view] [source] [discussion] 2024-05-10 06:23:56
>>steve_+Dj
Regarding compute speed - it checks out. Humans "think" via neo cortex, thin ouside layer of the brain. Poor locality, signals needs to travel a lot. Easy to expand though. Crow brain have everything tightly concentrated in the center - fast communication between neurons, hard to have more "thinking" thing later (therefore hard to evolve above what crows currently have)
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17. nickle+7O1[view] [source] [discussion] 2024-05-10 15:50:37
>>Animat+Z6
Badly: https://www.lesswrong.com/posts/mHqQxwKuzZS69CXX5/whole-brai... (the comments have some updates as of 2023)

Almost every other cell in the worm can be simulated with known biophysics. But we don't have a clue how any individual nematode neuron actually works. I don't have the link but there are a few teams in China working on visualizing brain activity in living C. elegans, but it's difficult to get good measurements without affecting the behavior of the worm (e.g. reacting to the dye).

replies(1): >>RaftPe+2Xj
18. gofred+pc2[view] [source] 2024-05-10 17:59:26
>>teuobk+(OP)
That is awesome !

the sheer number of things that work in co-ordination to make biology work!

In-f*king-credible !

19. oniony+LB2[view] [source] 2024-05-10 20:30:31
>>teuobk+(OP)
Hmm, that website does not honour my keyboard layout. Not sure how they managed that.
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20. djmips+2M2[view] [source] [discussion] 2024-05-10 21:50:39
>>nickle+e4
It's amusing to say that bird brains are on the next generation node size.
replies(1): >>sigmoi+st3
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21. sdento+S53[view] [source] [discussion] 2024-05-11 01:32:13
>>Terr_+7v
Humans are an n=1 example, is my point. And there's no direct competition between bird brain architecture and mammalian brain architecture, so there's no reason for one architecture to 'win' over the other - they may both be interesting local maxima, which we have no ability to directly compare.

Human brains might not be all that efficient; for example, if the competitive edge for primate brains is distinct enough, they'll get big before they get efficient. And humans are a pretty 'young' species. (Look at how machine learning models are built for comparison... you have absolute monsters which become significantly more efficient as they are actually adopted.)

By contrast, birds are under extreme size constraints, and have had millions of years to specialize (ie, speciate) and refine their architectures accordingly. So they may be exceedingly efficient, but have no way to scale up due to the 'need to fly' constraint.

replies(1): >>lostlo+qi4
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22. philsn+ag3[view] [source] [discussion] 2024-05-11 04:40:10
>>steve_+Dj
Not a dumb question at all; one of the hard constraints of cou design is signal propagation time. Even going at 1/3 the speed of light, when you only have on the order of a billionth of a second (clock frequencies in the GHz), a signal can’t get very far.

I haven’t heard of a clocking mechanism in brains, but signals propagate much slower and a walnut / crow brain is much larger than a cpu die.

replies(1): >>RaftPe+M24
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23. sigmoi+st3[view] [source] [discussion] 2024-05-11 08:24:30
>>djmips+2M2
Would be interesting to see what their wafer yield is. Like, are they more or less prone to mental disease.
replies(1): >>ruined+N04
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24. tlarkw+6F3[view] [source] [discussion] 2024-05-11 11:50:21
>>steve_+Dj
The electrical signals in brain are chemical reactions, not conductivity like a metal wire. They are slow! Synaptic junctions are a huge number of indirect chemical cascades, not a direct electrical connection, they are even slower! So brain morphology and connectome has a massive impact on what can be computed. Human twitch responses are done by cerebellum, not cerebrum. It's faster, but you can't do philosophy with the cerebellum, only learn to ride a bike etc. This is the brain doing the best it for the circumstances.
replies(1): >>ganesh+Zo4
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25. JKCalh+IG3[view] [source] [discussion] 2024-05-11 12:19:15
>>steve_+Dj
And here I was wondering if there were heat issues in a crow brain.
replies(1): >>steve_+3t4
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26. ruined+N04[view] [source] [discussion] 2024-05-11 15:54:18
>>sigmoi+st3
all the crows can tell i'm crazy, but i've never met an insane crow.
replies(1): >>dudein+Vo4
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27. RaftPe+M24[view] [source] [discussion] 2024-05-11 16:13:12
>>philsn+ag3
> I haven’t heard of a clocking mechanism in brains

Brain waves (partially). They aren't exactly like a cpu clock, but they do coordinate activity of cells in space and time.

There are different frequencies that are involved in different types of activity. Lower frequencies synchronize across larger areas (can be entire brain) and higher frequencies across smaller local areas.

There is coupling between different types of waves (i.e. slow wave phase coupled to fast waves amplitude) and some researchers (Miller) thinks the slow wave is managing memory access and the fast wave is managing cognition/computation (utilizing the retrieved memory).

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28. m3kw9+td4[view] [source] [discussion] 2024-05-11 18:06:18
>>jamiek+F2
Physics of the universe is the most complex thing in the universe
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29. lostlo+qi4[view] [source] [discussion] 2024-05-11 19:00:22
>>sdento+S53
> And there's no direct competition between bird brain architecture and mammalian brain architecture

By and large It’s not direct competition but we are stamping our species at an alarming rate and birds are taking a hammering.

replies(2): >>bornfr+m05 >>sdento+066
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30. dudein+Vo4[view] [source] [discussion] 2024-05-11 20:14:44
>>ruined+N04
I dunno anyone who screams “Caw! CAW!”, raids garbage and poops in the street all day would probably be put in a mental institution. (Or just move to San Francisco.)
replies(1): >>twothr+ar4
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31. ganesh+Zo4[view] [source] [discussion] 2024-05-11 20:15:21
>>tlarkw+6F3
>The electrical signals in brain are chemical reactions, not conductivity like a metal wire.

Nerve signals are both chemical reactions and electrical impulses like metal wire. Electrical impulses are sent along the fat layer by ions Potassium , Calcium, Sodium etc.

Twitch responses are actually done in spinal cord. The signals are short circuited all along the spine and return back to muscle without touching the brain ever.

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32. twothr+ar4[view] [source] [discussion] 2024-05-11 20:41:50
>>dudein+Vo4
You say that, but a world with more crows than tax payers honestly sounds kind of serene.
replies(1): >>prerok+Ix4
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33. steve_+3t4[view] [source] [discussion] 2024-05-11 21:06:15
>>JKCalh+IG3
Throw some thermal paste on those neurons and they do just fine
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34. robgib+dv4[view] [source] [discussion] 2024-05-11 21:31:05
>>jamiek+F2
Can a hand grasp itself?
replies(1): >>danpar+zW4
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35. prerok+Ix4[view] [source] [discussion] 2024-05-11 22:04:54
>>twothr+ar4
Well, The Stand from Stephen King comes to mind when you say that.

There was a short series filmed, that I enjoyed, but definitely not strong.

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36. danpar+zW4[view] [source] [discussion] 2024-05-12 05:38:51
>>robgib+dv4
No, but neither can it compose a symphany.
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37. bornfr+m05[view] [source] [discussion] 2024-05-12 07:03:27
>>lostlo+qi4
I wonder if dinosaurs said the same thing about mammals.
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38. sdento+066[view] [source] [discussion] 2024-05-12 19:32:49
>>lostlo+qi4
Are humans able to destroy all this habitat because they've got a better brain architecture, because they are able to achieve higher brain mass (because they don't need to fly to survive), or because they have opposable thumbs?

There's too many confounding factors to say that the human brain architecture is actually 'better' based on the outcomes of natural selection. And if we kill all the birds, we will lose the chance to find out as we develop techniques to better compare the trade-offs of the different architectures.

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39. wg0+2d6[view] [source] [discussion] 2024-05-12 20:24:39
>>jamiek+F2
And yet recall all the hype and claims around LLMs reaching AGI within few years.

LLMs that work at a very crude level of string tokens and emit probabilities.

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40. RaftPe+2Xj[view] [source] [discussion] 2024-05-17 14:12:32
>>nickle+7O1
Here's a timely bit of new research: https://www.science.org/doi/10.1126/sciadv.adk0002

Summary (my paraphrasing):

They partially figured out how two neurons (AVA, AVB) control forward and backward movement, previous theories assumed one neuron controlled forward and one controlled backward, but that didn't correctly model actual movement.

They found that AVA+AVB combine in a complex mechanism with two different signaling/control methods acting at different timescales to produce a graded shifting between forward+backward when switching directions, as opposed to an on/off type switch (that previous models used but didn't match actual movements).

Interesting learnings from this paper (at least for me):

1-Most neurons in worm are non-spiking (I had no idea, I've read about this stuff a lot and wasn't aware)

2-Non-spiking neurons can have multiple resting states at different voltages

3-Neurons AVA and AVB are different, they each have different resting state characteristics and respond differently to inputs

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