Intrigued by the article, but no, not convinced. For a variety of reasons, including some we talked about in the last couple of sessions. Moravec's basic measurement baseline is the MIP, ie a million instructions processed per second by a CPU. Alternatively characterized in recent years by computer scientists themselves in the plural as "Meaningless Indication of Processor Speed". Which is to say that even in a contemporary serial computer, it is recognized that the speed of the processor itself is frequently not the most significant variable in actual performance.

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.