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"Large-scale neural simulations are difficult for computers because neural models do not map onto the Von Neumann architecture." I'm not sure I buy that. I can
by timtrueman 18y ago
"Large-scale neural simulations are difficult for computers because neural models do not map onto the Von Neumann architecture."
I'm not sure I buy that. I can understand if speed is a big deal but I just can't imagine neural models do not map onto current computers. I'd like to see an example proving that sentence.
- debt 18y agoIf the brain operated on the Von Neumann architecture, your thoughts would be processed tremendously slow while expending an enormous amount of energy. Perhaps the long lost ancestors of the human had brains operating on this principle, but simply couldn't store enough energy to survive. The brain fires off multiple synapses in multiple places in the brain at different times. If the brain worked like a Von Neumann machine, it could only fire one synapse at one place in the brain at one particular point in time. The brain executes things in parallel while the Von Neumann is sequential. The brain is incredibly more efficient then the Von Neumann machine I'm using to type this comment on. Also, why do you not buy this assessment?
- timtrueman 18y agoSo basically you guys are saying it's way faster, but not that it's not technically impossible to do in software on normal computers. I'm just not sure it's NOT cheaper and faster to prototype this stuff in software and then build it in hardware to make it faster once they figure it out. Prototyping in hardware seems slower and more expensive to me... And FYI I am familiar with neural networks (and artificial neural networks, I've written a few) and I understand it's massively parallel and that neural networks the size of the human brain cannot be simulated on today's hardware but that's not the goal stated in this article. It just sounds like a bunch of guys that are really into hardware and so that's how they're going to do it, and there's nothing wrong with that. I just wanted to know if it's something that that isn't technically possible in software.
- jimbokun 18y agoTo me, it sounds like a bunch of guys who wrote a grant proposal general enough that they can do almost whatever they want after they get the money and still be within the scope of the proposal.
- debt 18y agoWe can't emulate complex brain models on a computer because we don't have the power. We shouldn't because it's incredible inefficient. IBM proposes finding a hardware model or some material that can be used to properly mimic synapses in the brain. The academic term for this would be neuromorphic engineering.
- bd 18y agoThey use analog building blocks, not digital ones: "Mead succeeded in mimicking ion-flow across a neuron's membrane with electron-flow through a transistor's channel. This should not have come as a surprise: the same physical forces are at work in both cases! A silicon neuron is an analog electronic circuit of transistors that mimic a real neuron's repertoire of ion-channels. Instead of designing different electronic circuits to emulate each of a wide variety of ion-selective protein pores that stud neurons' membranes, as Mead did in his silicon retina, we came up with a versatile silicon model." http://www.stanford.edu/group/brainsinsilicon/about.html http://www.stanford.edu/group/brainsinsilicon/about.html
- timtrueman 18y agoAnd analog circuits cannot be built/modeled in software?
- debt 18y agoIt's possible, but requires a massive supercomputer to do any reasonable calculations. Neuromorphic chips provide a way to minimize both the time and energy used in calculation by having physical chips act as synapses.