"It's very exciting," says Terrence Sejnowski, head of the Computational Neurobiology Laboratory at the Salk Institute, in La Jolla, CA. "The technology has matured to the point where it's possible to think about large-scale simulations." For example, Sejnowski studies how the thalamus, a brain area thought to relay and integrate information from different parts of the brain, interacts with the cortex. "We can currently do small simulations of hundreds to thousands of neurons, but it would be great to be able to scale that up," he says. The million-neuron grid will have a processing speed equivalent to 300 teraflops, meaning that unlike computer-software simulations of the cortex, the hardwired silicon model will be able to run in real time. "Instead of running a thousand software instructions, it's just current running through transistors, just like real neurons," says Boahen. Of course, the project will be a challenging one. "They will have to get a large number of chips to work together," says Douglas. "To put together a structure on the scale Kwabena has in mind--no one has done that yet." But it could become a turning point in the field. Douglas likens the current state of neuromorphic engineering to the early stages of computer-chip design. "People had been working on different types of logic gates, but it took a whole different worldview to build computer chips," he says.
Engineers ultimately hope to use the information generated by the silicon cortex in a variety of ways--to build better neural prostheses, for example. "The real-time aspect of this technology allows us in principle to interface the silicon cortex with the real cortex or brain," says Gert Cauwenberghs, a neuroengineer at the University of California, San Diego. "There is the promise, at least in the future, to build a prosthesis to replace some lost motor function or sensory function." |
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HP Rewires Electronics
05/05/2008
Comments
spicker on 02/12/2007 at 4:57 AM
4
TRAyres on 02/13/2007 at 4:59 AM
1
What, its not good enough for you to only have modelled two parts of the brain, they have to get the whole thing done before you take notice? Let me guess: You aren't very good at investing. Just a thought.
Honestly, saying this kind of research is hot air is like saying these 'darn computers' are just passing fads.
spicker on 02/13/2007 at 5:30 AM
4
Do not mistake, I think it is great that people model the various parts of the brain. However, one needs to carefully look at the assumptions and conditions set up for the model.
When Kwabena Boahen is planning to create 'a silicon model of the cortex' I think it is a bold statement to claim that he replicated it. No doubt he will find interesting answers and I am eager to see the results but also hesitant to expect the final solution.
When a transistor models a neuron, it models parts of its electrical properties and perhaps also wiring pattern. But seldomly, it takes into account all of its intricate chemical and physical functionality. The temporal aspects stemming from deprivation of neurotransmitter, enhancement of synapses, gene expression leading to additional receptors and the like, are most often not inherent in the silicon models presently suggested and I would question whether they are part of Boahen's but will appreciate it if it is the case.
No doubt Boahen's model will bring further understanding but I miss to see why this attempt is more special than the silicon attempts made previously.
NNemec on 02/13/2007 at 7:37 AM
1
Of course, one can try to model at various levels of refinement, but still everything that you put into the computer and call it "neuron" will be a model, unless it is a atom-by-atom simulation.
Obviously, such a complete simulation is impossible with todays and probably also next week's technology. But even more: it would not help us a bit in understanding. A replica is - by definition - exactly as complex as the original, so it is exactly as complicated to understand.
Only a reasonable model helps understanding. Scientists have to try different models to find out which aspects are important to capture the working of the original.
bshi on 02/13/2007 at 11:00 AM
1
> of refinement, but still everything that you put
> into the computer and call it "neuron" will be a
> model, unless it is a atom-by-atom simulation.
Nope; the atom is still a physical model.
spicker on 02/13/2007 at 3:31 PM
4
Sorry for the confusion.
I was triggered by the title 'Building the cortex in silicon' and failed to be as brief as the reply from stevenzenith.
ms on 02/12/2007 at 7:22 PM
64
reluctantelitist on 02/20/2007 at 7:44 AM
1
rajamouli2000 on 02/13/2007 at 2:58 AM
2
randcraw on 02/13/2007 at 11:19 AM
1
Also, large numbers of CPU ops/second are an easy claim when you ignore RAM bandwidth. To wit: a CPU with 64 bit registers + 3 GHz clock = 192 GigaOps. Multiply that by 3-4 functional units per CPU, and your laptop approaches a TeraOp.
So is every three year old PC a supercomputer?
Todd on 02/13/2007 at 12:37 PM
5
According to Ray Kurzweil, a desktop around the year 2020 should have the computing capacity to function at the speed of the human brain (2*10^16 cps).
There also have been models of the cerebellum, not just the inner ear.
spicker on 02/14/2007 at 3:50 AM
4
... or when feeling discomforted about having been too sarcastic in a comment to an article in a magazine.
stevenzenith on 02/13/2007 at 12:15 PM
2
WickedWitch on 02/13/2007 at 5:46 PM
1
vznuri on 02/14/2007 at 7:39 PM
1
computing? maybe something hebbian, or
similar to the SVD, singular value decomposition.
check for & discuss related cutting edge developments in algorithmics & mathematics at
the theory-edge mailing list,
http://groups.yahoo.com/group/theory-edge/
dallassmeltser on 03/15/2008 at 5:35 PM
1
Make a real brain like the rat heart.Then the testing could be better and easier..