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Simulating 1 second of real brain activity takes 40 minutes and 83K processors

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Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#101

Post by coldtea »

smosher wrote: post #82
jonmrodriguez wrote: post #67

Earlier quoted context omitted.

For example, the glial cells are now believed to be vital to the brain's processing, but most "brain simulations" are still modeling neurons only, not glia. http://shahamlab.rockefeller.edu/pdf/CTDB_69_C_69003.pdf

Not helpful. My question demands an answer from the person making the claim, unless you happen to know what they're thinking. Besides, this sounds nothing like what they're talking about. Worse, I don't think you're prepared to prove that a mostly pure-neuron simulation is incapable of giving rise to that certain complex quality apparently far removed from the level of the simulation.

>Not helpful. My question demands an answer from the person making the claim, unless you happen to know what they're thinking.

No, questions can be answered by anyone, if they provide a relevant answer.

What the person making the claim thought is irrelavent. The parent gave you a valid reply.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#102

Post by Retric »

luikore wrote: post #99
beloch wrote: post #92

If Moore's law were to continue to hold, this would mean the same simulation could operate in real-time on an 83K processor cluster in approximately 25 years or on one processor in about 50 years. Of course, this simulation is 1% of the neurons that a human brain has, and I don't know if scaling up to a full-brain would be linear (This probably depends on the average length of axons in the brain.). This completely un…

It's Penrose's view that a brain is quantum, but this paper http://arxiv.org/pdf/quant-ph/9907009v2.pdf shows human brain is more classical than quantum. Maybe the simulation algorithm is the thing that needs improvement. Some day one finds a way to reduce the complexity an order of magnitude, then the era of human brain is over.

~10 billion nerves * 10,000 connections per nerve * 100HZ * ~ 100 neurotransmitters = a complex beast to simulate even if you could get away with 1 calculation per connection per transmitter and ignore things like propagation delays and fatigue.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#103

Post by MacsHeadroom »

ck2 wrote: post #94
beloch wrote: post #92

If Moore's law were to continue to hold, this would mean the same simulation could operate in real-time on an 83K processor cluster in approximately 25 years or on one processor in about 50 years. Of course, this simulation is 1% of the neurons that a human brain has, and I don't know if scaling up to a full-brain would be linear (This probably depends on the average length of axons in the brain.). This completely un…

Or by 2020 they make an asic chip that emulates a brain cell and it computes 10x faster than realtime. Massive array at 8nm and there's your positronic brain.

Stanford and other groups have been working on "brain asics" for a few years now. The eventually success of these chip-sets will probably dramatically increase our ability to simulate brain processes more efficiently in the near future.

See http://www.stanford.edu/group/brainsinsilicon/about.html

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#104

Post by bbgm »

sgentle wrote: post #81
JamesArgo wrote: post #78

Earlier quoted context omitted.

When did reductionism become a dirty word?

I've noticed this too. I blame a combination of Zen and the Art of Motorcycle Maintenance and not knowing what the word actually means. From my observation, it appears people assume "reductionist" means "simplistic" as opposed to "representing a complex system as no more than the sum of its components". To be honest, I think it's just an etymological problem: "reduction" sounds bad, so "reductionism" sounds bad. The…

Reductionism is fundamental to science. There are places where it shows it limits, but I've always equated being reductionist with being clever, with taking a complex question and re-casting it in terms that can be measured/studied using the current state of the art.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#105

Post by MacsHeadroom »

Retric wrote: post #102
luikore wrote: post #99

Earlier quoted context omitted.

It's Penrose's view that a brain is quantum, but this paper http://arxiv.org/pdf/quant-ph/9907009v2.pdf shows human brain is more classical than quantum. Maybe the simulation algorithm is the thing that needs improvement. Some day one finds a way to reduce the complexity an order of magnitude, then the era of human brain is over.

~10 billion nerves * 10,000 connections per nerve * 100HZ * ~ 100 neurotransmitters = a complex beast to simulate even if you could get away with 1 calculation per connection per transmitter and ignore things like propagation delays and fatigue.

Why calculate anything when we can make most of it happen in dedicated hardware? http://www.stanford.edu/group/brainsinsilicon/about.html

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#106

Post by thelamest »

wikiburner wrote: post #93
beloch wrote: post #92

If Moore's law were to continue to hold, this would mean the same simulation could operate in real-time on an 83K processor cluster in approximately 25 years or on one processor in about 50 years. Of course, this simulation is 1% of the neurons that a human brain has, and I don't know if scaling up to a full-brain would be linear (This probably depends on the average length of axons in the brain.). This completely un…

Roger Penrose has theorized the brain relies on quantum effects, but it seems to have been as discredited as something currently unfalsifiable can be discredited. http://en.wikipedia.org/wiki/Quantum_mind

It's not like there is a conspiracy against Penrose, there is just a prevailing feeling (which I for one subscribe to) that: "computation via quantum mechanical processes is irrelevant to explaining how brains produce thought, contrary to the ongoing speculations of many theorists. First, quantum effects do not have the temporal properties required for neural information processing. Second, there are substantial physical obstacles to any organic instantiation of quantum computation. Third, there is no psychological evidence that such mental phenomena as consciousness and mathematical thinking require explanation via quantum theory. We conclude that understanding brain function is unlikely to require quantum computation or similar mechanisms."

(http://watarts.uwaterloo.ca/~pthagard/Articles/quantum.pdf)

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#107

Post by 4ad »

beloch wrote: post #92

If Moore's law were to continue to hold, this would mean the same simulation could operate in real-time on an 83K processor cluster in approximately 25 years or on one processor in about 50 years. Of course, this simulation is 1% of the neurons that a human brain has, and I don't know if scaling up to a full-brain would be linear (This probably depends on the average length of axons in the brain.). This completely un…

> If quantum mechanics plays a role in the function of the brain we will need a quantum computer to do the job.

Not at all. A classical computer can accurately simulate a quantum computer, albeit slowly.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#108

Post by wikiburner »

thelamest wrote: post #106
wikiburner wrote: post #93

Earlier quoted context omitted.

Roger Penrose has theorized the brain relies on quantum effects, but it seems to have been as discredited as something currently unfalsifiable can be discredited. http://en.wikipedia.org/wiki/Quantum_mind

It's not like there is a conspiracy against Penrose, there is just a prevailing feeling (which I for one subscribe to) that: "computation via quantum mechanical processes is irrelevant to explaining how brains produce thought, contrary to the ongoing speculations of many theorists. First, quantum effects do not have the temporal properties required for neural information processing. Second, there are substantial phys…

Oh, yeah. Totally agree, I must have worded it poorly. I'm just saying all theories are technically "speculative" until we can replicate cognition, but his quantum theories sound unnecessary and hand-wavey, akin to "The Soul".

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#109

Post by hannibal5 »

pygy_ wrote: post #98
hannibal5 wrote: post #48

Earlier quoted context omitted.

They use it to understand brain. So they wire it like the brain is wired. If they simulate cortex, they wire arrange it into cortical columns (size of each column is between 50,000 and 100,000 neurons and there is over two million of them). Those columns have many different layers and neuron types. Understanding how cortical columns and minicolumns work is very important.

You made my point regarding small scale simulation, but completely missed the rest. > So they wire it like the brain is wired. As if anyone knew how to do that. Even assuming that you can do both accurate micro-tractography and extract cell-by cell epigenetic information out of a single column, you'd still be missing other cricial information like individual synaptic strength. I'm not talking about cortico-thalamic c…

> but far from the real deal.

Your real deal has nothing to do with current brain science and these simulations.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#110

Post by pygy_ »

hannibal5 wrote: post #109
pygy_ wrote: post #98

Earlier quoted context omitted.

You made my point regarding small scale simulation, but completely missed the rest. > So they wire it like the brain is wired. As if anyone knew how to do that. Even assuming that you can do both accurate micro-tractography and extract cell-by cell epigenetic information out of a single column, you'd still be missing other cricial information like individual synaptic strength. I'm not talking about cortico-thalamic c…

> but far from the real deal. Your real deal has nothing to do with current brain science and these simulations.

With these simulations, definitely, that was the point.

With current brain science, call me perplexed. Could detail were you think I'm off base?

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