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Cubic millimetre of brain mapped at nanoscale resolution

nature.com

171–180 of 205 posts

Re: Cubic millimetre of brain mapped at nanoscale resolution

#171

Earlier quoted context omitted.

Try asking an LLM about something which is semantically patently ridiculous, but lexically superficially similar to something in its training set, like "the benefits of laser eye removal surgery" or "a climbing trip to the Mid-Atlantic Mountain Range". Ironically, I suppose part of the apparent "intelligence" of LLMs comes from reflecting the intelligence of human users back at us. As a human, the prompts you provide…

Like humans, multi-modal frontier LLMs will ignore "removal" as an impertinent typo, or highlight it. This, like everything else in the comment, is either easily debunked (e.g. try it, read the lit. on LLM extrapolation), or so nebulous and handwavy as to be functionally meaningless. We need an FAQ to redirect "statistical parrot" people to, saving words responding to these worn out LLM misconceptions. Maybe I should…

I didn't know that metaphysics, consciousness, and the physical complexities of my neurology are considered solved problems, though I suppose anything is as long as you handwave the unsolved parts as "functionally meaningless".

Re: Cubic millimetre of brain mapped at nanoscale resolution

#172
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…

I love that analogy with birds!

Yes we figured out how to build aircraft.

But it can not be compared to a bird flying. Neither in terms of efficiency or elegance.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#173
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.

I just read that article and enjoyed it. Thanks for sharing! I don’t think the author was arguing biological processes can’t be reverse engineered, but rather that the tools and approaches typically used by biology researchers may not be as effective as tools and approaches used by engineers.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#174

Earlier quoted context omitted.

I mean, Hinton’s premises are, if not quite clearly wrong, entirely speculative (which doesn't invalidate the conclusions about efficienct that they are offered to support, but does leave them without support) GPT-4 can produce convincing written text about a wider array of topics than any one person can, because it's a model optimized for taking in and producing convincing written text, trained extensively on writte…

Try asking an LLM about something which is semantically patently ridiculous, but lexically superficially similar to something in its training set, like "the benefits of laser eye removal surgery" or "a climbing trip to the Mid-Atlantic Mountain Range". Ironically, I suppose part of the apparent "intelligence" of LLMs comes from reflecting the intelligence of human users back at us. As a human, the prompts you provide…

Prompted to LlamaV3 70B

What are the benefits of laser eye removal surgery?

> I think there may be a misunderstanding. There is no such thing as "laser eye removal surgery." However, I assume you meant to ask about the benefits of LASIK (Laser-Assisted In Situ Keratomileusis) eye surgery, which is a type of refractive surgery that reshapes the cornea to improve vision.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#175
post #9

Earlier quoted context omitted.

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?

Can a hand grasp itself?

No, but neither can it compose a symphany.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#176

Earlier quoted context omitted.

I'm not aware that (base) LLMs use any form of database to generate their answers- so yes, all their knowledge is stored in their hundreds of billions of synapses.

Fair enough. OTOH, generating human-like text responses is a relatively small part of the human brain's skillset.

I don't know - it's about the best I can manage some days...

Re: Cubic millimetre of brain mapped at nanoscale resolution

#177

Earlier quoted context omitted.

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, t…

> 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.

I wonder if dinosaurs said the same thing about mammals.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#178

> The brain fragment was taken from a 45-year-old woman when she underwent surgery to treat her epilepsy. It came from the cortex, a part of the brain involved in learning, problem-solving and processing sensory signals. Wonder how they figured out which fragment to cut out.

The manuscript gives some details in the context of the difficulty of obtaining larger useful samples in the future and the difficulty of understanding if a sample is typical or pathological.

Re: Cubic millimetre of brain mapped at nanoscale resolution

#179

> Jain’s team then built artificial-intelligence models that were able to stitch the microscope images together to reconstruct the whole sample in 3D How do they know if their AI did it correctly or not?

they don't and talk about the difficulties in their paper. I found it refreshing to see the standard of frankness and openness in how they address this. But - it's all pretty compelling and will surely prompt and sustain a lot more research investigating these results and data and also creating more in the future.
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