What the brain's wiring looks like • Hacker News Board

Re: What the brain's wiring looks like

#41

Post by criddell » Thu, Jul 06, 2017, 1:31 AM UTC

skndr wrote: post #16

criddell wrote: post #13

Where is the neuron cell body? Would they be at the outside where the fibers (axons?) seem to terminate? I wouldn't have guessed that it would look so linear. I was expecting a much more tangled appearance.

The tangled part is actually mostly 2mm thickness on the surface[0]. That's why the folds matter so much: [0] https://28oa9i1t08037ue3m1l0i861-wpengine.netdna-ssl.com/wp-... Check out this article for a pretty cool overview of the brain: https://waitbutwhy.com/2017/04/neuralink.html

Thank you! Great links.

Re: What the brain's wiring looks like

#42

Post by wildmusings » Thu, Jul 06, 2017, 1:57 AM UTC

wu-ikkyu wrote: post #27

s-macke wrote: post #7

Earlier quoted context omitted.

You should first define what actually means "understanding the brain" before you try to answer this question. Does "understanding of the brain" mean, that we can construct or simulate a brain? An artificial brain, which reproduce our intelligence and consciousness? There is no reason to believe, that we can't do this. A brain is part of our world, governed by physics. However, we will never be able to understand the…

>There is no reason to believe, that we can't do this. A brain is part of our world, governed by physics. How do you know consciousness is "governed" by our contemporary understanding of physics?

It's unfortunate that you're being downvoted. This is a classic and unsolved problem in the philosophy of mind and the people stating confidently that of course the mind is a purely physical system are ignoring many problems with that hypothesis, not least the lack of any conclusive evidence for it.

Re: What the brain's wiring looks like

#43

Post by alanbernstein » Thu, Jul 06, 2017, 1:59 AM UTC

booleandilemma wrote: post #3

Just wondering... How complicated does a brain have to become in order to understand itself? Could a brain exist that is so complicated that it could not understand itself, or does a brain's understanding always scale up with its complexity?

It's fun to think that this is a sufficient definition of consciousness.

Re: What the brain's wiring looks like

#44

Post by JepZ » Thu, Jul 06, 2017, 1:59 AM UTC

odreem wrote: post #36

The real challenge here is to understand the brain, and consciousness, without putting it in computer terminology. https://aeon.co/essays/your-brain-does-not-process-informati...

Sorry, but the author of that article clearly does not understand... It doesn't matter if humans store data the way computers do, the point is, that humans can be abstracted as state machines.

Yes, humans are certainly different than our PCs today, but that does not mean that the principles are so different. E.g. humans seem to use a lot of lossy 'compression' while that is something we try to avoid in software in recent years. So we use computers for the things humans cannot do very well and therefore it appears that we are different.

I think the whole discussion about putting the human mind into computer terminology is more about accepting that humans are just biological machines versus believing that humans are special because they have a soul and are different than any other animal.

Re: What the brain's wiring looks like

#45

Post by JepZ » Thu, Jul 06, 2017, 2:00 AM UTC

It's a tree ;-)

Re: What the brain's wiring looks like

#46

Post by aristidb » Thu, Jul 06, 2017, 2:08 AM UTC

nacc wrote: post #17

Just to clarify, these MRI images looks at white matter, which are mostly bundles of long-range myelinated axons. This is more likely a map of major highways in the brain (Or really the map of bundles of major highways in the brain, as MRI only has millimeter resolution). The connectome at the cellular level is massive. I think part of the mouse visual cortical connectome has been mapped out, and the data is on the o…

The article indirectly says it's using special MRI machines with much better than millimeter resolution. So I think your first analogy is likely better than your second.

Re: What the brain's wiring looks like

#47

Post by booleandilemma » Thu, Jul 06, 2017, 2:13 AM UTC

vinchuco wrote: post #40

booleandilemma wrote: post #3

Just wondering... How complicated does a brain have to become in order to understand itself? Could a brain exist that is so complicated that it could not understand itself, or does a brain's understanding always scale up with its complexity?

I remember hearing someone answer "if the brain was simple enough that we could understand it, it would be so simple that we wouldn't" to that question. Can a computer compute itself?

So we can only understand the brain because it is complex.

The brain may be the only object with this property.

Re: What the brain's wiring looks like

#48

Post by undershirt » Thu, Jul 06, 2017, 2:31 AM UTC

nacc wrote: post #17

Just to clarify, these MRI images looks at white matter, which are mostly bundles of long-range myelinated axons. This is more likely a map of major highways in the brain (Or really the map of bundles of major highways in the brain, as MRI only has millimeter resolution). The connectome at the cellular level is massive. I think part of the mouse visual cortical connectome has been mapped out, and the data is on the o…

I think I remember reading that mapping an entire human connectome would require all the world's current storage capacity?

Re: What the brain's wiring looks like

#49

Post by wakkaflokka » Thu, Jul 06, 2017, 2:32 AM UTC

monster_group wrote: post #11

booleandilemma wrote: post #3

Just wondering... How complicated does a brain have to become in order to understand itself? Could a brain exist that is so complicated that it could not understand itself, or does a brain's understanding always scale up with its complexity?

Questions such as these are tackled in the excellent book Infinity and the Mind [0]. [0] https://www.amazon.com/Infinity-Mind-Philosophy-Infinite-Pri...

I love these types of books. I'm about to buy this.

Is there any reason to get the most recent version (says "with a new preface by the author") over the $2 paperback?

Re: What the brain's wiring looks like

#50

Post by goatlover » Thu, Jul 06, 2017, 2:41 AM UTC

tux1968 wrote: post #33

wu-ikkyu wrote: post #27

Earlier quoted context omitted.

>There is no reason to believe, that we can't do this. A brain is part of our world, governed by physics. How do you know consciousness is "governed" by our contemporary understanding of physics?

It's not a question of our contemporary understanding being sufficient to model a human brain. Rather it's that there is little or no reason to believe the brain and consciousness are pure unassailable magic. So it should be within the scope of future scientific understanding.

The brain and consciousness need not be magic for the philosophical issue to arise. The fundamental question is objectivity vs subjectivity. Consciousness is subjective, yet science is an objective affair. Can the objective be used to explain the subjective, or is the objective an abstraction from intersubjective experiences?

If it's the latter, then the project to explain everything in scientific terms is doomed, because it will always leave something out. If it's the former, then subjectivity is not fundamental, but arises from the objective world. How this is so is a difficult matter (no pun intended).

Either way, there is no magic involved, just a question of where philosophical assumptions begin. You can start with matter or the mind and see where it takes you.