neuron-request@HPLMS2.HPL.HP.COM ("Neuron-Digest Moderator Peter Marvit") (09/26/90)
Neuron Digest Tuesday, 25 Sep 1990 Volume 6 : Issue 55 Today's Topics: Notice of Technical Reports PDP backprop on the Connection Machine Mactivation Word docs coming to ftp Shallice/Neuropsychology: BBS Multiple Book Review Re: Shallice/Neuropsychology: BBS Multiple Book review Re: Shallice/Neuropsychology: BBS Multiple Book review Reply Naturalo UCSD job opening: Cognitive Science Edelmannian nets? putting Edelman into practice Marr's VISION out of date MIND Workshop Announcement Send submissions, questions, address maintenance and requests for old issues to "neuron-request@hplabs.hp.com" or "{any backbone,uunet}!hplabs!neuron-request" Use "ftp" to get old issues from hplpm.hpl.hp.com (15.255.176.205). ------------------------------------------------------------ Subject: Notice of Technical Reports From: "Laveen N. KANAL" <kanal@cs.UMD.EDU> Date: Thu, 13 Sep 90 20:34:25 -0400 What follows is the abstract of a TR printed this summer which has been submitted for publication. Also included in this message are the titles of two earlier reports by the same authors which were put out in Dec. 1988 but which may be of interest now in view of some titles I have seen on the net. UMIACS-TR-90-99 July 1990 CS-TR-2508 ASYMMETRIC MEAN-FIELD NEURAL NETWORKS FOR MULTIPROCESSOR SCHECDULING Benjamin J. Hellstrom Laveen N. Kanal Abstract Hopfield and Tank's proposed technique for embedding optimization problems, such as the travelling salesman, in mean-field thermodynamic networks suffers from several restrictions. In particular, each discrete optimization problem must be reduced to the minimization of a 0-1 Hamiltonian. Hopfield and Tank's technique yields fully-connected networks of functionally homogeneous visible units with low-order symmetric connections. We present a program-constructive approach to embedding difficult problems in neural networks. Our derivation method overcomes the Hamiltonian reducibility requirement and promotes networks with functionally heterogeneous hidden units and asymmetric connections of both low and high-order. The underlying mechanism involves the decomposition of arbitrary problem energy gradients into piecewise linear functions which can be modeled as the outputs of sets of hidden units. To illustrate our method, we derive thermodynamic mean-field neural networks for multiprocessor scheduling. The performance of these networks is analyzed by observing phase transitions and several improvements are suggested. Tuned networks of up to 2400 units are shown to yield very good, and often exact solutions. The earlier reports are CS-TR-2149 Dec. 1988 by Hellstrom and Kanal, titled " Linear Programming Approaches to Learning in Thermodynamic Models of Neural Networks" Cs-TR-2150, Dec. 1988 by Hellstrom and Kanal, titled " Encoding via Meta-Stable Activation Levels: A Case Study of the 3-1-3 Encoder". Reports are available free until the current supply lasts after which they will be available(for a small charge) from the publications group at the Computer Science Center of the Univ. of Maryland, College Park, Md., 20742. The address for the current su supply is : Prof. L.N. Kanal, Dept. of Computer Science, A.V. Williams Bldg, Univ. ofMaryland, College Park, MD. 20742. L.K. ------------------------------ Subject: PDP backprop on the Connection Machine From: Sebastian Thrun <gmdzi!st@relay.EU.net> Date: Sat, 15 Sep 90 13:21:06 -0200 The following might be interesting for everybody who works with the PDP backpropagation simulator and has access to a Connection Machine: ******************************************************** ** ** ** PDP-Backpropagation on the Connection Machine ** ** ** ******************************************************** For testing our new Connection Machine CM/2 I extended the PDP backpropagation simulator by Rumelhart, McClelland et al. with a parallel training procedure for the Connection Machine (Interface C/Paris, Version 5). Following some ideas by R.M. Faber and A. Singer I simply made use of the inherent parallelism of the training set: Each processor on the connection machine (there are at most 65536) evaluates the forward and backward propagation phase for one training pattern only. Thus the whole training set is evaluated in parallel and the training time does not depend on the size of this set any longer. Especially at large training sets this reduces the training time greatly. For example: I trained a network with 28 nodes, 133 links and 23 biases to approximate the differential equations for the pole balancing task adopted from Anderson's dissertation. With a training set of 16384 patterns, using the conventional "strain" command, one learning epoch took about 110.6 seconds on a SUN 4/110 - the connection machine with this SUN on the frontend managed the same in 0.076 seconds. --> This reduces one week exhaustive training to approximately seven minutes! (By parallelizing the networks themselves similar acceleration can be achieved also with smaller training sets.) The source is written in C (Interface to Connection Machine: PARIS) and can easily be embedded into the PDP software package. All origin functions of the simulator are not touched - it is also still possible to use the extended version without a Connection Machine. If you want to have the source, please mail me! Sebastian Thrun, st@gmdzi.uucp You can also obtain the source via ftp: ftp 129.26.1.90 Name: anonymous Password: <transmit your full e-mail address, e.g. st@gmdzi.uucp> ftp> cd pub ftp> cd gmd ftp> get pdp-cm.c ftp> bye ------------------------------ Subject: Mactivation Word docs coming to ftp From: Mike Kranzdorf <mikek@wasteheat.colorado.edu> Date: Mon, 17 Sep 90 09:31:50 -0600 [[ Editor's note at the end ]] I thought Connectionists might be interested in the end result of this, specifically that I will be posting a new copy of Mactivation 3.3 including MS Word documentation to alumni.colorado.edu real soon now. Date: Sun, 16 Sep 90 03:37:36 GMT-0600 From: james@visual2.tamu.edu (James Saxon) Message-Id: <9009160937.AA25939@visual2.tamu.edu> To: mikek@boulder.colorado.edu Subject: Mactivation Documentation I was going to post this to the net but I figured I'd let you do it if you feel it's necessary. If you're going to give out the bloody program, you might as well have just stuck in the decent readable documentation because nobody in their right mind is going to pay $5.00 for it. It's really a cheap move and if you don't replace the ftp file you might just lose all your business because, I like many others just started playing with the package. I don't see any macros for learning repetitive things and so I was going to give up because I don't want to spend all day trying to figure out how to not switch from the mouse to the keyboard trying to set the layer outputs for everything... And then I'm certainly not going to turn to an unformatted Geneva document just to prove that the program is not very powerful... So you can decide what you want do do but I suggest not making everybody pissed off at you. I sincerely apologize if my original posting gave the impression that I was trying to make money from this. Mactivation, along with all the documentation, has been available via ftp for over 3 years now. Since I recently had to switch ftp machines here, I thought I would save some bandwidth and post a smaller copy (in fact this was suggested by several people). Downloading these things over a 1200 baud modem is very slow. The point of documentation in this case is to be able to use the program, and I still think a text file does fine. The $5 request was not for prettier docs, but for the disk, the postage, and my time. I get plenty of letters saying "Thank you for letting me avoid ftp", and that was the idea. The $5 actually started as an alternative for people who didn't want to bother sending me a disk and a self addressed stamped envelope, which used to be part of my offer. However, I got too many 5 1/4" disks and unstamped envelopes, so I dropped that option this round. I am presently collecting NN software for a class that my professor is teaching here at A&M and will keep your program around for the students but I warn them about the users manual. :-0 And while this isn't a contest, your program will be competing with the Rochester Connectionist Simulator, SFINX, DESCARTES, and a bunch more... Lucky I don't have MacBrain... which if you haven't seen, you should. Of course, that's $1000, but the manual's free. If you think you're getting MacBrain for free or a Mac version of the Rochester Simulator, then don't bother downloading Mactivation. You will be dissapointed. I wrote Mactivation for myself, and it is not supported by a company or a university. It's not for research, it's an introduction which can be used to teach some basics. (Actually you can do research, but only on the effects of low-level parameters on small nets. As a point of interest, my research involved making optical neural nets out of spatial light modulators, and these parameters were important while the ability to make large or complex nets was not.) James Saxon Scientific Visualization Laboratory Texas A&M University james@#visual2.tamu.edu ***The end result of this is that I will post a new copy complete with the Word docs. I am not a proficient telecommunicator though, so it may take a week or so. I apologize for the delay. --mikek internet: mikek@boulder.colorado.edu uucp:{ncar|nbires}!boulder!mikek AppleLink: oblio [[ Editor's Note: I hope Mike does not get disgruntled by the tone of Mr. Saxon who seems to want a great deal for very little $$$. I, for one, appreciate Mactivation for what it is (and has been advertised). I have given copies to several of my colleagues; they are all pleased with the functionality and the price. I'm sure Mr. Saxon will educate himself, however, on the subtleties of acquiring commercial AND academic software and dealing with fellow researchers in a professional manner -PM ]] ------------------------------ Subject: Shallice/Neuropsychology: BBS Multiple Book Review From: Stevan Harnad <harnad@clarity.Princeton.EDU> Date: Mon, 17 Sep 90 23:02:16 -0400 Below is the abstract of a book that will be accorded multiple book review in Behavioral and Brain Sciences (BBS), an international, interdisciplinary journal that provides Open Peer Commentary on important and controversial current research in the biobehavioral and cognitive sciences. Commentators must be current BBS Associates or nominated by a current BBS Associate. To be considered as a commentator on this book, to suggest other appropriate commentators, or for information about how to become a BBS Associate, please send email to: harnad@clarity.princeton.edu or harnad@pucc.bitnet or write to: BBS, 20 Nassau Street, #240, Princeton NJ 08542 [tel: 609-921-7771] To help us put together a balanced list of commentators, please give some indication of the aspects of the topic on which you would bring your areas of expertise to bear if you are selected as a commentator. ____________________________________________________________________ BBS Multiple Book Review of: FROM NEUROPSYCHOLOGY TO MENTAL STRUCTURE Tim Shallice MRC Applied Psychology Unit Cambridge, UK ABSTRACT: Studies of the effects of brain lesions on human behavior are now cited more widely than ever, yet there is no agreement on which neuropsychological findings are relevant to our understanding of normal function. Despite the range of artefacts to which inferences from neuropsychological studies are potentially subject -- e.g., resource differences between tasks, premorbid individual differences and reorganisation of function -- they are corroborated by similar findings in studies of normal cognition (short-term memory, reading, writing, the relation between input and output systems and visual perception). The functional dissociations found in neuropsychological studies suggest that not only are input systems organized modularly, but so are central systems. This conclusion is supported by considering impairments of knowledge, visual attention, supervisory functions, memory and consciousness. ------------------------------ Subject: Re: Shallice/Neuropsychology: BBS Multiple Book review From: jpk@ingres.com (Jon Krueger) Date: 20 Sep 90 04:03:36 +0000 [[ Editor's note: This topic (and Mr. Krueger's comments, are revelant to Neural Networks for the following questions: How do we analyze networks to know what their parts are doing? Do the connectionist models of brain lesions provide any insight into the biology? What level of analysis is appropriate for these artifical models 9as well as for the brain lesion steudies themselves)? -PM ]] > ABSTRACT: Studies of the effects of brain lesions on human behavior are > now cited more widely than ever Wrong. No one has studied the effect of brain lesions on human behavior, and no one is about to. Observations of the behavior of individuals with lesions are reported, sometimes reliably. Testing before and after the lesion is seldom done. Random assignment of subjects or lesions is never done. Ethical restrictions simply don't permit it. Therefore, you can't vary independent variables like location of lesion, hold other variables constant or randomize for them, and discover the effect on dependent variables like behavior. We have some guesses about what brain lesions do to human behavior, but we can't study it scientifically. Therefore it shouldn't surprise anyone that > there is no agreement on which neuropsychological findings are relevant > to our understanding of normal function. Since there are some manipulations we can do ethically, we might expect to get some agreement by doing some science using them. You're also engaging in egregious sort-crossing. Brain events are not mixable with mental ones. Cutting remarks don't produce lesions. Injecting dye into brains doesn't produce colorful thoughts. Neurons don't have ideas. Holmes can't ask Doyle for more interesting cases. Holmes can't count the number of pages in the book. Similarly, brain and mentality are not the same sort of phenomena. Statements that mix terms from the two lexicons are unlikely to mean anything. -- Jon Jon Krueger, jpk@ingres.com ------------------------------ Subject: Re: Shallice/Neuropsychology: BBS Multiple Book review From: tony@nexus.yorku.ca (Tony Wallis) Organization: York University Department of Computer Science Date: 21 Sep 90 01:10:13 +0000 Responding to Stevan Harnad, Jon Krueger writes : | > [Review of] FROM NEUROPSYCHOLOGY TO MENTAL STRUCTURE [by] Tim Shallice | > ... | > ABSTRACT: Studies of the effects of brain lesions on human behavior are | > now cited more widely than ever. ... | Wrong. No one has studied the effect of brain lesions on human | behavior, and no one is about to. ... | You're also engaging in egregious sort-crossing. Brain events are not | mixable with mental ones. ... | ... Holmes can't ask Doyle for more interesting cases. ... ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Yes he can. Holmes can review his philosophical position, decide that he has a creator and ask that creator to modify his world. From "below" (within the fictional world of Holmes) this appears to be religious or something similar. From "above" (the world of you, me and the mind and writing of Doyle) this appears as Doyle dialoging with himself. In either case, it is a quite valid thing to do. I am not being facetious here. Just pointing out that you are making some metaphysical assumptions in your strict partitioning of brain and mind events. ... tony@nexus.yorku.ca = Tony Wallis, York University, Toronto, Canada ------------------------------ Subject: Reply Naturalo From: SCHOLTES%ALF.LET.UVA.NL@CUNYVM.CUNY.EDU Date: Tue, 18 Sep 90 22:12:00 +0700 Subject: RE: Natural Language Parsing (E.S. Atwell, Vol. 90-54) Dear Eric, Here are some references on parsing NLP in NN. Do also pay attention to other, less classical attempt like the work done by Elman and Allen. They change the nature of the parsing problem by representing it as a problem in time. As a result, recursion techniques are not needed anymore. Even more interesting are Self-organizing NN for the automatic detemination of structure by exposing the system to language strings, right now I am working on this aspect, I can send you (and the rest of the digest) more on it at the end of the month. Good Luck Jan C. Scholtes Univ. of Amsterdam Department of Computational Linguistics Faculty of Arts THE NETHERLANDS -------------------------- References [Akker et al., 1989]: Akker, R. op den, Alblas, H., Nijholt, A. and Oude Luttinghuis, P. (1989). An Annotated Bibliography on Parallel Parsing. Memoranda Informatia 89-67, Universiteit van Twente, [Fanty, 1985]: Fanty, M. (1985). Context-Free Parsing in Connectionist Networks. TR 174, Computer Science, University of Rochester, [Hanson et al., 1987]: Hanson, S.J. and Kegl, J. (1987) PARSNIP: A connectionist Network that Learns Language Grammar From Exposure to Natural Langauage Sentences, Proceedings of the Cog. Sci. Conf, Seattle, 1987. [Jelinek et al., 1989]: Jelinek, F., Fusijaki, T., Cocke, J., Black, E. and Nishino, T. (1989). A Probabilistic Parsing Method for Sentence Disambiguation. CMU International Parsing Workshop, 1989, pp. 85-94. [Li et al., 1987]: Li, T. and Chun, H.W. (1987). A Massively Parallel Network-based Natural Language Parsing System. Proceedings of the 2nd International Conference on Computers and Applications, [McClelland et al., 1986]: McClelland, J.L. and Kawamoto, A.H. (1986). Mechanisms of Sentence Processing: Assigning Roles to Constituents of Sentences. Parallel Distributed Processing, (D.E. Rumelhart, J.L. McClelland Eds.), Vol 2, pp. 273-325. MIT Press [Nijholt, 1989]: Nijholt, A. (1989). Parallel Parsing Strategies in Natural Language Processing. Memoranda Informatica 89-41, Universiteit Twente, [Nijholt, 1990]: Nijholt, A. (1990). Meta-Parsing in Neural Networks. Memoranda Informatica 90-08, Universiteit Twente, [Nijholt, 1990]: Nijholt, A. (1990). The CYK-Approach to Serial and Parallel Parsing. Memoranda Informatica 90-13, Universteit Twente, [Selman et al., 1987]: Selman, B. and Hirst, G. (1987). Parsing as an Energy Minimization Problem. Genetic Algorithms and Simulated Annealing, (L. Davis Editor), Pian, London. [Sikkel, 1990]: Sikkel, N. (1990). Connectionist Parsing of Context-Free Grammars. Memoranda Informatica 90-30, Universiteit Twente, [Small et al., 1982]: Small, S., Cottrell, G. and Shastri, L. (1982). Toward Connectionist Parsing. Proceedings of the National Conference on AI, Pittsburg, PA, August 1982, pp. 247-250. [Tanenhaus et al., 1987]: Tanenhaus, M.K., Dell, S.G. and Carlson, G. (1987). Context Effects and Lexical Processing: A Connectionist Approach to Modularity. Modularity in Knowledge Representation and NLU, (J.L. Garfield, Ed.), MIT Press, Cambridge. [Waltz et al., 1985]: Waltz, D.L. and Pollack, J.B. (1985). Massively Parallel Parsing. Cognitive Science, Vol. 9, Number 1, January-March, pp. 51-74. Also consider: The chapter on NLP in Mathew Zeidenbergs' excellent book on NN: Neural Networks in Artificial Intelligence. Here a good review of the efforts made in NLP and NN is given in a clear and understandable way. ------------------------------ Subject: UCSD job opening: Cognitive Science From: elman@amos.ucsd.edu (Jeff Elman) Date: Tue, 18 Sep 90 12:44:31 -0700 Assistant Professor Cognitive Science UNIVERSITY OF CALIFORNIA, SAN DIEGO The Department of Cognitive Science at UCSD expects to receive permission to hire one person at the assistant professor level (tenure-track). We seek someone whose interests cut across conventional disciplines. The Department takes a broadly based approach covering experimental, theoretical, and computational investigations of the biological basis of cognition, cognition in individuals and social groups, and machine intelligence. Candidates should send a vita, reprints, a short letter describing their background and interests, and names and addresses of at least three references to: UCSD Search Committee/Cognitive Science 0515e 9500 Gilman Dr. La Jolla, CA 92093-0515-e Applications must be received prior to January 15, 1991. Salary will be commensurate with experience and qualifications, and will be based upon UC pay schedules. Women and minorities are especially encouraged to apply. The University of California, San Diego is an Affirmative Action/Equal Opportunity Employer. ------------------------------ Subject: Edelmannian nets? From: "Bruce E. Nevin" <bnevin@ccb.bbn.com> Date: Wed, 19 Sep 90 08:46:46 -0400 Vivek Anumolu (anumolu@cis.uab.edu) asks "fellow NN researchers" the question "Anyone using Eldelman's theories?" NN researcher I am not, I am only an interested consumer of this list, so this may very well be far off the mark, but it seem to me that work on GANNET (Generation and Adaptation of Neural Networks by Evolutionary Techniques) may fill the bill. This British project involves Logica, Meiko, the engineering department of the University of Cambridge, and the physiology department of the University of Oxford. I have read only a summary report of it in _New Scientist_ for 25 August 1990 (p. 28). It refers not to Edelman but to Richard Dawkins' book _The Blind Watchmaker_. They use genetic algorithm techniques in the design and iterative refinement of neural nets. Don't know how they deal with scaling problems (toy problems and/or small nets in the pool and/or small number of trial nets in the pool, so as not to overrun resources, problem then is can you scale results up to more complex situations). Perhaps some UK participant can say more. The NS article quotes Clifton Hughes at Logica. Someone on the GA list may know more too. Bruce ------------------------------ Subject: putting Edelman into practice From: Stephen Smoliar <smoliar@vaxa.isi.edu> Date: Wed, 19 Sep 90 07:04:22 -0700 Vivek Anumolu inquired as to why there is currently not a lot of activity in pursuing Gerald Edelman's theory of Neuronal Group Selection. First of all, for the benefit of all readers interested in this question, I offer up the following entry from the list of technical reports currently on file at ISI: NEURONAL GROUP SELECTION THEORY : A GROUNDING IN ROBOTICS. Donnett, Jim; Smithers, Tim. University of Edinburgh, DAI RP 461. November, 1989. I have read this report, and it is rather preliminary. I shall be passing through Edinburgh at the end of this month and hope to learn more about their effort then. Of course, a single report does not constitute "a lot of activity." The primary answer to Vivek's question is magnitude. Computational models of Neuronal Group Selection require FAR more computational resources than connectionism. Consequently, the sorts of phenomena which the Edelman group can currently demonstrate may be written off as trivial by connectionists. (Needless to say, the Edelman group is not building such systems to generate trivialities. They are actually more interested in modeling the underlying BIOLOGICAL phenomena, so it makes sense to begin with the simplest of tasks.) Furthermore, if you want to rise above the level of simple perceptual categorization, you have to build up several additional layers of selection mechanisms. Edelman's latest book, THE REMEMBERED PRESENT, is his current working hypothesis of what this layered architecture might look like. Needless to say, if you do not have enough compute power to build an implementation of the lowest layer for "real" data, building on top of that layer is practically out of the question. Needless to say, many of Edelman's ideas are still appealing. I am particularly taken with his attempt to describe memory as a process of "recategorization." I must confess that I still to not have a clear idea of what he means by this because it runs against my intuitions of a "file cabinet" memory where objects remain static in fixed locations. Nevertheless, I think it is worth while to try to pursue Edelman's vision of a memory which is constantly in a state of flux, responding as a dynamic system to every interaction with some sort of global reorganization. I can think of two questions which deserve investigation and can probably be pursued independent of attempts to implement perceptual categorization for "real" data: 1. From a computational point of view, what would such a memory look like? Would it be a variation on a PDP architecture? Could it maintain an explicit representation of symbols; or would all phenomena have to "emerge" from patterns of activation? 2. Could we build such a memory to serve a hybrid system? Suppose, for example, we are trying to retrieve from a memory of actions in order to establish what action to take in a given situation. Could that memory of actions be maintained with a system which employs recategorization? How would the agent trying to decide what actions to take interact with that memory? I am just beginning to think about these questions and would certainly appreciate thoughts offered up by other readers of this Digest. ------------------------------ Subject: Marr's VISION out of date From: slehar@bucasd.bu.edu Date: Thu, 20 Sep 90 07:11:15 -0400 In the last Neuron Digest (V6 #54) honig@ICS.UCI.EDU (David A. Honig) quotes my comments on Grossberg's BCS/FCS vision model, and goes on to say... "Connectionists interested in this reasoning, and in the important relationship between functionality, algorithm, and implementation, and how these should be analyzed, might want to read David Marr's book, _Vision_ (WH Freeman & Co, 1982)." David Marr's book VISION is delightfully lucid and beautifully illustrated, and I thoroughly agree with his analysis of the three levels of modelling. Nevertheless I believe that there are two fatal flaws in the philosophy of his vision model. The first fatal flaw is the feedforward nature of his model, from the raw primal sketch through the 2&1/2 D sketch to the 3-D model representation. Decades of "image understanding" and "pattern recognition" research have shown us that such feed-forward processing has a great deal of difficulty with natural imagery. The problem lies in the fact that whenever "feature extraction" or "image enhancement" are performed, they recognize or enhance some features but in the process they inevitably degrade others or introduce artifacts. With successive levels of processing the artifacts accumulate until at the highest levels of processing there is no way to distinguish the real features from the artifacts. Even in our own vision, with all its sophistication, we occasionally see things that are not there. The real problem here is that once a stage of processing is performed, it is never reviewed or reconsidered. Grossberg has shown how nature solves this problem, by use of top-down feedback. Whenever a feature is recognized at any level, a copy of that feature is passed back DOWN the processing hierarchy in an attempt to improve the match at the lower levels. If for instance a set of disconnected edges suggest a larger continuous edge to a higher level, that "hypothesis" is passed down to the local edge detectors to see if they can find supporting evidence for the missing pieces by locally lowering their detection thresholds. If a faint edge is indeed found, it is enhanced by resonant feedback. If however there is strong local opposition to the hypothesis then the enhancement is NOT performed. This is the cooperative / competitive loop of the BCS model which serves to disambiguate the image by simultaneous matching at multiple levels. This explains why, when we occasionally see something that isn't there, we see it in such detail until at a higher level a conflict occurs, at which time the apparation "pops" back to being something more reasonable. The second fatal flaw in Marr's vision model is related to the first. In the finest tradition of "AI", Marr's 3-D model is an abstract symbolic representation of the visual input, totally divorced from the lower level stimuli which generated it. The great advance of the "neural network" perspective is that manipulation of high level symbols is meaningless without regard to the hierarchy of lower level representations to which they are attached. When you look at your grandmother for instance, some high level node (or nodes) must fire in recognition. At the same time however you are very conscious of the low level details of the image, the strands of hair, the wrinkles around the eyes etc. In fact, even in her absence the high level node conjurs up such low level features, without which that node would have no real meaning. It is only because that node rests on the pinacle of a hierarchy of such lower nodes that is has a meaning of "grandmother". The perfectly gramatical sentence "Grandmother is purple" is only recognized as nonsense when visualized at the lowest level, illustrating that logical processing cannot be separated from low level visualization. Although I recognize Marr's valuable and historic contribution to the understanding of vision, I believe that in this fast moving field we have already progressed to new insights and radically different models. I would be delighted to provide further information by email to interested parties on Grossberg's BCS model and my implementation of it. (O)((O))(((O)))((((O))))(((((O)))))(((((O)))))((((O))))(((O)))((O))(O) (O)((O))((( slehar@bucasb.bu.edu )))((O))(O) (O)((O))((( Steve Lehar Boston University Boston MA )))((O))(O) (O)((O))((( (617) 424-7035 (H) (617) 353-6741 (W) )))((O))(O) (O)((O))(((O)))((((O))))(((((O)))))(((((O)))))((((O))))(((O)))((O))(O) ------------------------------ Subject: MIND Workshop Announcement From: elsberry@arrisun3.arl.utexas.edu (Wes Elsberry) Date: Tue, 18 Sep 90 21:09:28 -0500 [[ Editor's Note: Abstracts will follow in the next issue. -PM ]] Announcement NEURAL NETWORKS FOR KNOWLEDGE REPRESENTATION AND INFERENCE Fourth Annual Workshop of the Metroplex Institute for Neural Dynamics (MIND) October 4-6, 1990 IBM Westlake, TX (near Dallas - Fort Worth Airport) Conference Organizers: Daniel Levine, University of Texas at Arlington (Mathematics) Manuel Aparicio, IBM Application Solutions Division Speakers will include: James Anderson, Brown University (Psychology) Jean-Paul Banquet, Hopital de la Salpetriere, Paris John Barnden, New Mexico State University (Computer Science) Claude Cruz, Plexus Systems Incorporated Robert Dawes, Martingale Research Corporation Richard Golden, University of Texas at Dallas (Human Development) Sam Leven, Radford University (Brain Research Institute) Janet Metcalfe, Dartmouth College (Psychology) Jordan Pollack, Ohio State University (Computer Science) Karl Pribram, Radford University (Brain Research Institute) Lokendra Shastri, University of Pennsylvania (Computer Science) Topics will include: Connectionist models of semantic comprehension. Architectures for evidential and case-based reasoning. Connectionist approaches to symbolic problems in AI such as truth maintenance and dynamic binding. Representations of logical primitives, data structures, and constitutive relations. Biological mechanisms for knowledge representation and knowledge-based planning. We plan to follow the talks by a structured panel discussion on the questions: Can neural networks do numbers? Will architectures for pattern matching also be useful for precise reasoning, planning, and inference? Tutorial Session: Robert Dawes, President of Martingale Research Corporation, will present a three hour tutorial on neurocomputing the evening of October 3. This preparation for the workshop will be free of charge to all pre-registrants. ----------------------------------------------------------------------------- Registration Form NEURAL NETWORKS FOR KNOWLEDGE REPRESENTATION AND INFERENCE Fourth Annual Workshop of the Metroplex Institute for Neural Dynamics (MIND) Name: _____________________________________________________ Affiliation: ______________________________________________ Address: __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ Telephone number: _________________________________________ Electronic mail: __________________________________________ Conference fee enclosed (please check appropriate line): $50 for MIND members before September 30 ______ $60 for MIND members on/after September 30 ______ $60 for non-members before September 30 ______ $70 for non-members on/after September 30 ______ $10 for student MIND members any time ______ $20 for student non-members any time ______ Tutorial session (check if you plan to attend): ______ Note: This is free of charge to pre-registrants. Suggested Hotels: Solana Marriot Hotel. Next to IBM complex, with continuous shuttle bus available to meeting site; ask for MIND conference rate of $80/night. Call (817) 430-3848 or (800) 228-9290. Campus Inn, Arlington. 30 minutes from conference, but rides are available if needed; $39.55 for single/night. Call (817) 860-2323. Conference programs, maps, and other information will be mailed to pre- registrants in mid-September. Please send this form with check or money order to: Dr. Manuel Aparicio IBM Mail Stop 03-04-40 5 West Kirkwood Blvd. Roanoke, TX 76299-0001 (817) 962-5944 [I have a set of abstracts available for download from Central Neural System BBS, U.S. telephone 817-551-9363. The filename is WORKABST.MND. -- Wesley R. Elsberry] ------------------------------ End of Neuron Digest [Volume 6 Issue 55] ****************************************