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Cubic millimetre of brain mapped at nanoscale resolution

nature.com

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Re: Cubic millimetre of brain mapped at nanoscale resolution

#161

Post by ben_w »

NexusMethod wrote: post #156

After reading through all comments as of 2024/05/11 I (as a professor at some major university) am quite surprised that not one single comment has asked the obvious question (instead of dishing out loads of (partial) "textbook knowledge" about brain functions, the difference between mammals and birds, AI and LLM etc.), which would be: what do all those strange structures and objects do which we know nothing about wha…

Neat, thanks.

As a complete outsider who doesn't know what to look for, the dendrite inside soma (dendrite from one cell tunnelling through the soma of another) was the biggest surprise.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#162

Post by prerok »

twothreeone wrote: post #157
dudeinjapan wrote: post #152

Earlier quoted context omitted.

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.)

You say that, but a world with more crows than tax payers honestly sounds kind of serene.

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.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#163

Post by hotiwuer324234 »

ein0p wrote: post #142

As important and impressive a result as this is, I am reminded of the cornerstone problem of neuroscience, which goes something like this: if we knew next to nothing about processors but could attach electrodes to the die, would we be able to figure out how processors execute programs and what those programs do, in detail, just from the measurements alone? And now scale that up several orders of magnitude and introdu…

The reverse-engineering issue was popularized by this article, https://www.cell.com/cancer-cell/fulltext/S1535-6108%2802%29...

On the second point, the failure of Openworm to model the very well-mapped-out C. elegans (~0.3k neurons) says a lot.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#164

Post by hotiwuer324234 »

lll-o-lll wrote: post #158
ein0p wrote: post #142

As important and impressive a result as this is, I am reminded of the cornerstone problem of neuroscience, which goes something like this: if we knew next to nothing about processors but could attach electrodes to the die, would we be able to figure out how processors execute programs and what those programs do, in detail, just from the measurements alone? And now scale that up several orders of magnitude and introdu…

Right. The arguments for the study of A.I. were that you will not discover the principles of flight by looking at a birds feather under an electron microscope. It’s fascinating, but we aren’t going to understand intelligence this way. Emergent phenomenon are part of complexity theory, and we don’t have any maths for it. Our ignorance in this space is large. When I was young, I remember a common refrain being “will a…

> but we aren’t going to understand intelligence this way

The same argument holds for "AI" too. We don't understand a damn thing about neural networks.

There's more - we don't care to understand them as long as it's irrelevant to exploiting them.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#165

Post by hotiwuer324234 »

throw310822 wrote: post #55
throwup238 wrote: post #12

> The 3D map covers a volume of about one cubic millimetre, one-millionth of a whole brain, and contains roughly 57,000 cells and 150 million synapses — the connections between neurons. This is great and provides a hard data point for some napkin math on how big a neural network model would have to be to emulate the human brain. 150 million synapses / 57,000 neurons is an average of 2,632 synapses per neuron. The adu…

Or you can subscribe to Geoffrey Hinton's view that artificial neural networks are actually much more efficient than real ones- more or less the opposite of what we've believed for decades- that is that artificial neurons were just a poor model of the real thing. Quote: "Large language models are made from massive neural networks with vast numbers of connections. But they are tiny compared with the brain. “Our brains…

> "So maybe it’s actually got a much better learning algorithm than us.”

And yet somehow it's also infinitely less useful than a normal person is.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#166

Post by lll-o-lll »

hotiwuer324234 wrote: post #164
lll-o-lll wrote: post #158

Earlier quoted context omitted.

Right. The arguments for the study of A.I. were that you will not discover the principles of flight by looking at a birds feather under an electron microscope. It’s fascinating, but we aren’t going to understand intelligence this way. Emergent phenomenon are part of complexity theory, and we don’t have any maths for it. Our ignorance in this space is large. When I was young, I remember a common refrain being “will a…

> but we aren’t going to understand intelligence this way The same argument holds for "AI" too. We don't understand a damn thing about neural networks. There's more - we don't care to understand them as long as it's irrelevant to exploiting them.

> The same argument holds for "AI" too. We don't understand a damn thing about neural networks.

Yes, which is why the current explosion in practical application isn’t very interesting.

> we don't care to understand them as long as it's irrelevant to exploiting them.

For some definition of “we”, I’m sure that’s true. We don’t need to understand things to make practical use of them. Giant Cathedrals were built without science and mathematics. Still, once we do have the science and mathematics, generally exponential advancement results.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#167

Post by dmarble »

NexusMethod wrote: post #156

After reading through all comments as of 2024/05/11 I (as a professor at some major university) am quite surprised that not one single comment has asked the obvious question (instead of dishing out loads of (partial) "textbook knowledge" about brain functions, the difference between mammals and birds, AI and LLM etc.), which would be: what do all those strange structures and objects do which we know nothing about wha…

I'm in awe at the complexity and unknowability of it all, but I also have to chuckle at the thought that some portion may be vestigial.

I'm particularly fond of the "Egg shaped object with no associated processes". :)

Re: Cubic millimetre of brain mapped at nanoscale resolution

#168

Post by NexusMethod »

dmarble wrote: post #167
NexusMethod wrote: post #156

After reading through all comments as of 2024/05/11 I (as a professor at some major university) am quite surprised that not one single comment has asked the obvious question (instead of dishing out loads of (partial) "textbook knowledge" about brain functions, the difference between mammals and birds, AI and LLM etc.), which would be: what do all those strange structures and objects do which we know nothing about wha…

I'm in awe at the complexity and unknowability of it all, but I also have to chuckle at the thought that some portion may be vestigial. I'm particularly fond of the "Egg shaped object with no associated processes". :)

me too! :-)

Re: Cubic millimetre of brain mapped at nanoscale resolution

#169

Post by p1esk »

hotiwuer324234 wrote: post #165
throw310822 wrote: post #55

Earlier quoted context omitted.

Or you can subscribe to Geoffrey Hinton's view that artificial neural networks are actually much more efficient than real ones- more or less the opposite of what we've believed for decades- that is that artificial neurons were just a poor model of the real thing. Quote: "Large language models are made from massive neural networks with vast numbers of connections. But they are tiny compared with the brain. “Our brains…

> "So maybe it’s actually got a much better learning algorithm than us.” And yet somehow it's also infinitely less useful than a normal person is.

GPT4 has been a lot more useful to me than most normal people I interact with.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#170

Post by signal_space »

NexusMethod wrote: post #168
dmarble wrote: post #167

Earlier quoted context omitted.

I'm in awe at the complexity and unknowability of it all, but I also have to chuckle at the thought that some portion may be vestigial. I'm particularly fond of the "Egg shaped object with no associated processes". :)

me too! :-)

wrt to the egg - could be excreting chemicals modulating the intracellular medium
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