neuron-request@HPLMS2.HPL.HP.COM ("Neuron-Digest Moderator Peter Marvit") (01/11/91)
Neuron Digest Thursday, 10 Jan 1991 Volume 7 : Issue 3 Today's Topics: TR - Symbol Processing Systems, Connectionist Nets, etc. Preprint: Stimulus Sampling & Distributed Representations TR on the Modelling of Synaptic Plasticity 4 vs 3 layers -- Tech Report available from connectionists archive Language, Tools and Brain: BBS Call for Commentators Consciousness: BBS Call for Commentators Full/Part-Time NN Research Assistant & Programmer Positions POSTDOCTORAL POSITION IN NEW YORK AREA: Cognitive & NeuralModels of Human Learn 4th NN Conference. Indiana-Purdue. 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: TR - Symbol Processing Systems, Connectionist Nets, etc. From: honavar@iastate.edu Date: Tue, 18 Dec 90 15:08:02 -0600 The following technical report is available in postscript form by anonymous ftp (courtesy Jordan Pollack of Ohio State Univ). Comments on the paper are welcome (please direct them to honavar@iastate.edu) _________________________________________________________________ Symbol Processing Systems, Connectionist Networks, and Generalized Connectionist Networks Vasant Honavar Leonard Uhr Department of Computer Science Computer Sciences Department Iowa State University University of Wisconsin-Madison Technical Report #90-24, December 1990 Department of Computer Science Iowa State University, Ames, IA 50011 Abstract Many authors have suggested that SP (symbol processing) and CN (connectionist network) models offer radically, or even fundamentally, different paradigms for modeling intelligent behavior (see Schneider, 1987) and the design of intelligent systems. Others have argued that CN models have little to contribute to our efforts to understand intelligence (Fodor & Pylyshyn, 1988). A critical examination of the popular characterizations of SP and CN models suggests that neither of these extreme positions is justified. There are many advantages to be gained by a synthesis of the best of both SP and CN approaches in the design of intelligent systems. The Generalized connectionist networks (GCN) (alternately called generalized neuromorphic systems (GNS)) introduced in this paper provide a framework for such a synthesis. ______________________________________________________________________________ You will need a POSTSCRIPT printer to print the file. To obtain a copy of the report, use anonymous ftp from cheops.cis.ohio-state.edu (here is what the transaction looks like): % ftp ftp> open cheops.cis.ohio-state.edu Connected to cheops.cis.ohio-state.edu. 220 cheops.cis.ohio-state.edu FTP server (Version blah blah) ready. Name (cheops.cis.ohio-state.edu:yourname): anonymous 331 Guest login ok, send ident as password. Password: anything 230 Guest login ok, access restrictions apply. ftp> cd pub/neuroprose 250 CWD command successful. ftp> bin 200 Type set to I. ftp> get honavar.symbolic.ps.Z 200 PORT command successful. 150 Opening BINARY mode data connection for [[...]] 226 Transfer complete. local: honavar.symbolic.ps.Z remote: honavar.symbolic.ps.Z 55121 bytes received in 1.8 seconds (30 Kbytes/s) ftp> quit 221 Goodbye. % uncompress honavar.symbolic.ps.Z % lpr honavar.symbolic.ps ------------------------------ Subject: Preprint: Stimulus Sampling & Distributed Representations From: gluck%psych@Forsythe.Stanford.EDU (Mark Gluck) Date: Wed, 19 Dec 90 07:29:57 -0800 PRE-PRINT AVAILABLE: Stimulus Sampling and Distributed Representations in Adaptive Network Theories of Learning Mark A. Gluck Department of Psychology Stanford University [To appear in: A. Healy, S. Kosslyn, & R. Shiffrin (Eds.), Festschrift for W. K. Estes. NJ: Erlbaum, 1991/in press] ABSTRACT: Current adaptive network, or "connectionist", theories of human learning are reminiscent of statistical learning theories of the 1950's and early 1960's, the most influential of which was Stimulus Sampling Theory, developed by W. K. Estes and colleagues (Estes, 1959; Atkinson & Estes, 1963). This chapter reviews Stimulus Sampling Theory, noting some of its strengths and weaknesses, and compares it to a recent network model of human learning (Gluck & Bower, 1986, 1988a,b). The network model's LMS learning rule for updating associative weights represents a significant advance over Stimulus Sampling Theory's more rudimentary learning procedure. In contrast, Stimulus Sampling Theory's stochastic scheme for representing stimuli as distributed patterns of activity can overcome some limitations of network theories which identify stimulus cues with single active input nodes. This leads us to consider a distributed network model which embodies the processing assumptions of our earlier network model but employs stimulus-representation assumptions adopted from Stimulus Sampling Theory. In this distributed network, stimulus cues are represented by the stochastic activation of overlapping populations of stimulus elements (input nodes). Rather than replacing the two previous learning theories, this distributed network combines the best established concepts of the earlier theories and reduces to each of them as special cases in those training situations where the previous models have been most successful. _________________________________________________________________ To request copies, send email to: gluck@psych.stanford.edu with your hard-copy mailing address. Or mail to: Mark A. Gluck, Department of Psychology, Jordan Hall, Bldg. 420, Stanford Univ., Stanford, CA 94305-2130 ------------------------------ Subject: TR on the Modelling of Synaptic Plasticity From: Patrick Thomas <thomasp@informatik.tu-muenchen.dbp.de> Date: 27 Dec 90 13:27:38 +0100 The following technical report is now available: BEYOND HEBB SYNAPSES: BIOLOGICAL BUILDING BLOCKS FOR UNSUPERVISED LEARNING IN ARTIFICIAL NEURAL NETWORKS Patrick V. Thomas Report FKI-140-90 Abstract This paper briefly reviews the neurobiology of synaptic plasticity as it is related to the formulation of learning rules for unsupervised learning in artificial neural networks. Presynaptic, postsynaptic and heterocellular mechanisms are discussed and their relevance to neural modelling is assessed. These include a variety of phenomena of potentiation as well as depression with time courses of action ranging from milliseconds to weeks. The original notion put forward by Donald Hebb stating that synaptic plasticity depends on correlated pre- and postsynaptic firing is reportedly inadequate. Although postsynaptic depolarization is necessary for associative changes in synaptic strength to take place (which conforms to the spirit of the hebbian law) the association is understood as being formed between pathways converging on the same postsynaptic neuron. The latter only serves as a supporting device carrying signals between activated dendritic regions and maintaining long-term changes through molecular mechanisms. It is further proposed to restrict the interactions of synaptic inputs to distinct compartments. The hebbian idea that the state of the postsynaptic neuron as a whole governs the sign and magnitude of changes at individual synapses is dropped in favor of local mechanisms which guide the depolarization-dependent associative learning process within dendritic compartments. Finally, a framework for the modelling of associative and non-associative mechanisms of synaptic plasticity at an intermediate level of abstraction, the Patchy Model Neuron, is sketched. To obtain a copy of the technical report FKI-140-90 please send your physical mail address to either "thomasp@lan.informatik.tu-muenchen.de" or Patrick V. Thomas, Institute for Medical Psychology, Goethe-31, 8000 Munich 2, Germany. ------------------------------ Subject: 4 vs 3 layers -- Tech Report available from connectionists archive From: sontag@control.RUTGERS.EDU Date: Mon, 07 Jan 91 11:37:04 -0500 REPORT AVAILABLE ON CAPABILITIES OF FOUR-LAYER vs THREE-LAYER NETS At the request of a few people at NIPS, I placed in the connectionists archive the postscript version of my report describing why TWO hidden layers are sometimes necessary when solving function-approximation types of problems, a fact that was mentioned in my poster. (About 1/2 of the report deals with the general question, while the other half is devoted to the application to control that led me to this.) Below are the abstract and instructions on ftp retrieval. I would very much welcome any discussion of the practical implications -- if any -- of the result. If you want, send email to me and I can summarize later for the net. Happy palindromic year to all, -eduardo ----------------------------------------------------------------------------- Report SYCON-90-11, Rutgers Center for Systems and Control, October 1990 FEEDBACK STABILIZATION USING TWO-HIDDEN-LAYER NETS This report compares the representational capabilities of three-layer (that is, "one hidden layer") and four-layer ("two hidden layer") nets consisting of feedforward interconnections of linear threshold units. It is remarked that for certain problems four layers are required, contrary to what might be in principle expected from the known approximation theorems. The differences are not based on numerical accuracy or number of units needed, nor on capabilities for feature extraction, but rather on a much more basic classification into "direct" and "inverse" problems. The former correspond to the approximation of continuous functions, while the latter are concerned with approximating one-sided inverses of continuous functions ---and are often encountered in the context of inverse kinematics determination or in control questions. A general result is given showing that nonlinear control systems can be stabilized using four layers, but not in general using three layers. ----------------------------------------------------------------------- To obtain copies of the postscript file, please use Jordan Pollack's service: Example: unix> ftp cheops.cis.ohio-state.edu # (or ftp 128.146.8.62) Name (cheops.cis.ohio-state.edu:): anonymous Password (cheops.cis.ohio-state.edu:anonymous): <ret> ftp> cd pub/neuroprose ftp> binary ftp> get (remote-file) sontag.twolayer.ps (local-file) twolayer.ps.Z ftp> quit unix> uncompress twolayer.ps unix> lpr -P(your_local_postscript_printer) twolayer.ps ---------------------------------------------------------------------------- If you have any difficulties with the above, please send e-mail to sontag@hilbert.rutgers.edu. DO NOT "reply" to this message, please. ------------------------------ Subject: Language, Tools and Brain: BBS Call for Commentators From: Stevan Harnad <harnad@clarity.Princeton.EDU> Date: Thu, 20 Dec 90 22:55:40 -0500 Below is the abstract of a forthcoming target article to appear 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 article, 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. ____________________________________________________________________ Language, Tools, and Brain: The development and evolution of hierarchically organized sequential behavior Patricia Marks Greenfield Department of Psychology University of California, UCLA Los Angeles, CA 90024-1563 electronic mail: rygreen@uclasscf.bitnet Abstract: During the first two years of life a common neural substrate (roughly, Broca's area) underlies the hierarchically organized combination of elements in the development of both speech and manual action, including tool use. The neural evidence implicates relatively specific cortical circuitry underlying a grammatical "module." Behavioral and neurodevelopmental data suggest that the modular capacities for language and manipulation are not present at birth but come into being gradually during the third and fourth years of life. An evolutionary homologue of the common neural substrate for language production and manual action during the first two years of human life is hypothesized to have provided a foundation for the evolution of language before the divergence of hominids and the great apes. Support comes from the discovery of a Broca's area analogue in contemporary primates. In addition, chimpanzees have an identical constraint on hierarchical complexity in both tool use and symbol combination. Their performance matches that of the two-year-old child who has not yet developed the differentiated neural circuits for the relatively modularized production of complex grammar and complex manual construction activity. ------------------------------ Subject: Consciousness: BBS Call for Commentators From: Stevan Harnad <harnad%phoenix.Princeton.EDU@VM.TCS.Tulane.EDU> Date: Fri, 21 Dec 90 12:55:58 -0500 Below is the abstract of a forthcoming target article to appear 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 article, 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. (The article is retrievable by anonymous ftp from directory /pub/harnad as file velmans.bbs on princeton.edu, however, please do not prepare a commentary unless you have been formally invited to do so.) ____________________________________________________________________ IS HUMAN INFORMATION PROCESSING CONSCIOUS? Max Velmans Department of Psychology Goldsmiths College University of London electronic mail: MLV@gold.lon.ac.uk KEY WORDS: consciousness, information processing, brain, unconscious, attention, mind, functionalism, reductionism, complementarity. ABSTRACT: Investigations of the function of consciousness in human information processing have focused mainly on two questions: (1) where does consciousness enter into the information processing sequence and (2) how does conscious processing differ from preconscious and unconscious processing. Input analysis is thought to be initially "preconscious," "pre-attentive," fast, involuntary, and automatic. This is followed by "conscious," "focal-attentive" analysis which is relatively slow, voluntary, and flexible. It is thought that simple, familiar stimuli can be identified preconsciously, but conscious processing is needed to identify complex, novel stimuli. Conscious processing has also been thought to be necessary for choice, learning and memory, and the organization of complex, novel responses, particularly those requiring planning, reflection, or creativity. This target article reviews evidence that consciousness performs none of these functions. Consciousness nearly always results from focal-attentive processing (as a form of output) but does not itself enter into this or any other form of human information processing. This suggests that the term "conscious process" needs re-examination. Consciousness appears to be necessary in a variety of tasks because they require focal-attentive processing; if consciousness is absent, focal-attentive processing is absent. From a first-person perspective, however, conscious states are causally effective. First-person accounts are complementary to third-person accounts. Although they can be translated into third-person accounts, they cannot be reduced to them. ------------------------------ Subject: Full/Part-Time NN Research Assistant & Programmer Positions From: gluck%psych@Forsythe.Stanford.EDU (Mark Gluck) Date: Mon, 31 Dec 90 20:50:24 -0800 Two Full/Part Time Research Assistant Positions in: --------------------------------------------------- COGNITIVE PSYCHOLOGY / NEURAL NETWORK MODELING at Rutgers University Center for Molecular & Behavioral Neuroscience 195 University Avenue Newark, NJ 07102 Two research positions are available for persons interested in pursuing empirical and/or theoretical research in the in cognitive and neural sciences. The positions are ideal for someone who has just graduated with an undergraduate degree and would like a year or two of "hands on" experience in research before applying to graduate school in one of the cognitive sciences (e.g., neuroscience, psychology, computer science). We are looking for two people: 1. RESEARCH PROGRAMMER: A person with strong programming skills to work in the development of computational theories of the neural & cognitive bases of learning. Familiarity with current PDP/neural-network algorithms and research would be helpful, as would experience with C/Unix and Sun computer systems. Work would either focus on the development of network models of human learning and/or biological-circuit models of the neural bases of animal learning. 2. EXPERIMENTAL RESEARCH ASSISTANT: A person with experience in running and designing human cognitive psychology experiments to work in the design, execution, and data analysis of behavioral studies of human categorization learning. __________________________________________________________________________ Other Information: FACILITIES: The Center is a new state-funded research center for the integrated studies of cognitive, behavioral, and molecular neuroscience. The Center has good computational resources and experimental laboratories for behavioral and neural studies. LOCATION: The Center is located in Newark, NJ, approximately 20 minutes outside of Manhattan, New York (with easy train and subway access to midtown and downtown NYC) and close to rural New Jersey countryside. Numerous other research centers in the cognitive and neural sciences are located nearby, e.g.: Cognitive Science Center, Rutgers/New Brunswick; Centers for Cognitive & Neural Science, New York University; Cognitive Science Center, Princeton Univ.; Columbia Univ. & Medical School; Siemens Corporate Research, Princeton, NJ; NEC Research Labs, Princeton, NJ; AT&T Labs; Bellcore; IBM T. J. Watson Research Labs. CURRENT FACULTY: E. Abercrombie, G. Buzsaki, I. Creese, M. Gluck, H. Poizner, R. Siegel, P. Tallal, J. Tepper. Six additional faculty will be hired. The center has a total of ten state-funded postdoctoral positions and will direct, in collaboration with the Institute for Animal Behavior, a graduate program in Behavioral and Neural Sciences. ---------------------------------------------------------------------------- For more information on learning research at the CMBN/Rutgers or to apply for these post-doctoral positions, please send cover letter with a statement of your research interests, a CV, copies of relevant preprints, and the the names & phone numbers of references to: Dr. Mark A. Gluck Phone: (415) 725-2434 Dept. of Psychology <-[Current address to 4/91] FAX: (415) 725-5699 Jordan Hall; Bldg. 420 Stanford University email: gluck@psych.stanford.edu Stanford, CA 94305-2130 ------------------------------ Subject: POSTDOCTORAL POSITION IN NEW YORK AREA: Cognitive & NeuralModels of Human Learning From: gluck%psych@Forsythe.Stanford.EDU (Mark Gluck) Date: Mon, 31 Dec 90 20:57:22 -0800 Postdoctoral Positions in: -------------------------- COGNITIVE & NEURAL BASES OF LEARNING at Rutgers University Center for Molecular & Behavioral Neuroscience 195 University Avenue Newark, NJ 07102 Postdoctoral positions are available for recent Ph.D's in all areas of Cognitive Science (e.g., Neuroscience, Psychology, Computer Science) interested in pursuing empirical and/or theoretical research in the following areas of cognitive and neural science: 1. COGNITIVE SCIENCE/ADAPTIVE "CONNECTIONIST" NETWORKS: Experimental and theoretical (computational) studies of human learning and memory. 2. COMPUTATIONAL NEUROSCIENCE / COGNITIVE NEUROSCIENCE: Models of the neural bases of learning in animals and humans. Candidates with any (or all) of the following skills are particular encouraged to apply: (1) familiarity with neural network algorithms and models, (2) strong computational/analytic skills, and (3) experience with experimental methods, experimental design, and data analysis in cognitive psychology. ---------------------------------------------------------------------------- Other Information: FACILITIES: The Center is a new state-funded research center for the integrated studies of cognitive, behavioral, and molecular neuroscience. The Center has good computational resources and experimental laboratories for behavioral and neural studies. LOCATION: The Center is located in Newark, NJ, approximately 20 minutes outside of Manhattan, New York (with easy train and subway access to midtown and downtown NYC) and close to rural New Jersey countryside. Numerous other research centers in the cognitive and neural sciences are located nearby including: Cognitive Science Center, Rutgers/New Brunswick; Centers for Cognitive & Neural Science, New York University; Cognitive Science Center, Princeton Univ.; Columbia Univ. & Medical School; Siemens Corporate Research, Princeton, NJ; NEC Research Labs, Princeton, NJ; AT&T Labs; Bellcore; IBM T. J. Watson Research Labs. CURRENT FACULTY: E. Abercrombie, G. Buzsaki, I. Creese, M. Gluck, H. Poizner, R. Siegel, P. Tallal, J. Tepper. Six additional faculty will be hired. The Center has a total of ten state-funded postdoctoral positions and will direct, in collaboration with the Institute for Animal Behavior, a graduate program in Behavioral and Neural Sciences. ---------------------------------------------------------------------------- For more information on learning research at the CMBN/Rutgers or to apply for these post-doctoral positions, please send a cover letter with a statement of your research interests, a CV, copies of relevant preprints, and the the names & phone numbers of references to: Dr. Mark A. Gluck Phone: (415) 725-2434 Dept. of Psychology <-[Current address to 4/91] FAX: (415) 725-5699 Jordan Hall; Bldg. 420 Stanford University email: gluck@psych.stanford.edu Stanford, CA 94305-2130 ------------------------------ Subject: 4th NN Conference. Indiana-Purdue. From: SAYEGH%IPFWCVAX.BITNET@vma.CC.CMU.EDU Date: Fri, 21 Dec 90 21:55:00 -0500 FOURTH CONFERENCE ON NEURAL NETWORKS ------------------------------------ AND PARALLEL DISTRIBUTED PROCESSING ----------------------------------- INDIANA UNIVERSITY-PURDUE UNIVERSITY ------------------------------------ 11,12,13 APRIL 1991 ------------------- CALL FOR PAPERS --------------- The Fourth Conference on Neural Networks and Parallel Distributed Processing at Indiana University-Purdue University will be held on the Fort Wayne Campus, April 11,12, 13, 1991. Authors are invited to submit a one page abstract of current research in their area of Neural Networks Theory or Application before February 5, 1991. Notification of acceptance or rejection will be sent by February 28. The proceedings of the third conference are now in press and will be announced on the network in early January. Conference registration is $20 and students attend free. Some limited financial support might also be available to allow students to attend. Abstracts and inquiries should be addressed to: email: sayegh@ipfwcvax.bitnet ----- US mail: ------- Prof. Samir Sayegh Physics Department Indiana University-Purdue University Fort Wayne, IN 46805 FAX: (219) 481-6880 Voice: (219) 481-6157 ------------------------------ End of Neuron Digest [Volume 7 Issue 3] ***************************************