Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site allegra.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!vek From: vek@allegra.UUCP (Van Kelly) Newsgroups: net.ai Subject: Re: Reinventing Man Message-ID: <3002@allegra.UUCP> Date: Thu, 31-Jan-85 00:19:25 EST Article-I.D.: allegra.3002 Posted: Thu Jan 31 00:19:25 1985 Date-Received: Thu, 31-Jan-85 06:39:02 EST References: <4464@ucbvax.ARPA> Reply-To: vek@allegra.UUCP (Van Kelly) Distribution: net Organization: AT&T Bell Laboratories, Murray Hill Lines: 29 Summary: In article <4464@ucbvax.ARPA> vijay@ucbvax.ARPA (Vijay Ramamoorthy) writes: > > Has anyone read "Reinventing Man" (1981) by I. Aleksander and P. Burnett? >Its about an architectural "neural net" model for the mind that, it is >claimed, has been constructed and is in use in Britain. The claim is >further made that it can recognize, to a degree, faces (even faces which >are partially disguised). ********************************* Recognition of images (including faces) with a "sensory net" model of memory is not all that new. I'll look into this book, but I'd also recommend a little monograph (late 70's vintage) by Tuevo Kohonen (published by Springer) to "demythologize" a lot of the "neural net" processor claims. Kohonen built a very simple, regular, matrix-connected memory array with nothing more complicated than linear mathematics at each node (an elegant "gutless wonder", with but limited resemblance to neural interconnection topologies). His mathematics showed that the performance of such a device in associative recall tasks was a function of the ration of raw AVAILABLE storage to net IN-USE storage (number of images stored). Basically, this "dirt-simple" device used its surplus storage to adaptively encode the images for maximal information-theoretic "distance" between image traces. Sounds fancy, but the math was really simple. So the question I always ask myself when I hear about "neural net" pattern-recognition performance is whether it represents more than just a constant-factor improvement on this "brute-force" result. Kohonen suggested that the only way a network might radically improve over his basic equations (modulo a constant factor) was to incorporate extensive non-linear distributed feature extraction in the hardware.