April 5, 2006 - 11:44
Projects:
Here is the paper I mentioned in class during our discussion of whether or not computers will ever be able to achieve behavioral complexity comparable to that of humans: When will computer hardware match the human brain, by Hans Moravec in 1997.
"This paper describes how the performance of AI machines tends to improve at the same pace that AI researchers get access to faster hardware. The processing power and memory capacity necessary to match general intellectual performance of the human brain are estimated. Based on extrapolation of past trends and on examination of technologies under development, it is predicted that the required hardware will be available in cheap machines in the 2020s."
That soon? It sounds a little bit crazy, but the general idea is pretty solid, in my opinion: that eventually, in the not-too-distant future (maybe not quite so soon as 2022) computers will easily rival or surpass human intelligence.
I would be interested to know whether or not Moravec can convince Professor Grobstein.
Comments
Computers, brains, and the future ....
Submitted by PaulGrobstein on April 5, 2006 - 18:07 Permalink
What's much more important though is that the brain is NOT a serial computer. Its a parallel network of something in the vicinity of 1012 neurons whose processing speed individually is .... hard to be certain of (is it digital or analogue?, running on discrete or continuous time? For fun, one might guess that neurons are processing 106 "instructions" (?) per second since many can generate a million signals a second. On this estimate, the nervous system is as a whole processing 1018 MIPS. This is substantially (to put it mildly) greater than Moravec's estimate of 108. The discrepancy is that Moravec's estimate is based on the number of instructions a serial computer needs to do a particular task in the retina (one of many), which he then presumes to be characteristic of any volume of not only the retina but the entire nervous system.
The brain is not only a parallel rather than a serial computer but a parallel computer with a very organized set of interconnections or architecture. So the problem is not only that of matching MIPS but also of simulating in a serial device the effects of the architecuture. I'm not sure there is any known way of guessing how much of an increase in MIPS would be necessary for this but I'm sure its quite substantial. Finally, as argued in class today, it seems pretty clear that the brain is designed as much for novelty generation as it is for particular computations aimed at unambiguously achieving particular tasks. Whether this increases or decreases the MIPS requirement I don't know but here too I'm disinclined to lay any money on Moravec's prediction that computers will "match general intellectual performance of the human brain ... in the 2020's".
As I hope I made clear in class, my skepticism isn't about whether artificial neural networks could in principle achieve all of the properties of the human brain; that the brain seems indeed to be a network of relatively simple elements says the answer is almost certainly yes. The tougher problems are getting clear exactly what those properties are, clarifying whether they can be simulated on a serial computer and, if so, writing the software to do so, and/or mimicking them with an artificial parallel device. There is a substantial likelihood that, if nothing else, the sheer size of the needed code for a serial device and/or the architectual demands for a parallel one will not only require a much longer time than Moravec predicts but may well preclude it ever being done other than emergently.
estimating processing power
Submitted by jrohwer on April 7, 2006 - 01:53 Permalink
hmm
Submitted by jrohwer on April 7, 2006 - 01:55 Permalink
More on brains and computers ... and the universe
Submitted by PaulGrobstein on April 9, 2006 - 10:08 Permalink
They key issues are, in any case, actually not here but in the architectual realm and, as you say, in the "what if" realm. And there I'm a little less concerned about the latter than you are. We actually do already and every day create large numbers of emergent "intelligences" (we call them "babies"). And they do indeed create a variety of problems and hazards. But we also have several millenia at least of experience in working with such unpredictable machines and so know a fair amount both about their benefits and about how to guard against the associated risks.
You (and others) might be amused by efforts to estimate the computing power not only of brains but of the universe. See If the Universe Were a Computer. Interesting to think about whether these estimates do/do not have some of the same problems as Moravec.
Computers as intelligent as humans?
Submitted by SarahMalayaSniezek on April 11, 2006 - 23:35 Permalink