From reder+ at CMU.EDU Thu Dec 12 09:04:36 1996 From: reder+ at CMU.EDU (Lynne M Reder) Date: Thu, 12 Dec 1996 09:04:36 -0500 (EST) Subject: Post-Doctoral Position Available Message-ID: We are seeking a post-doctoral researcher to work on two projects, funded by two agencies. One project involves trying to model individual differences in performance using ACT-R, by estimating a single parameter difference among subjects and using this single parameter across tasks to try to account for individual subject behavior. The other project involves cognitive modeling in a less well developed and much simpler framework (the models are implemented in LISP) and looks a lot like ACT-R's declarative memory. This project involves trying to account for individual subject's performance in various memory tasks. The attempt here is not to estimate an individual difference parameter that is held constant across tasks, but we do try to account for behavioral data at a very fine-grain level, i.e., account for performance on individual trials. The first project is done in collaboration with Marsha Lovett and Christian Lebiere. The second project is in collaboration with Christian Schunn. We are interested in hiring someone either early in the new year or at the end of the academic year. If you are interested, please send me your resume electronically and specify when you would be available or prefer to start. * * * * * * * * * * * * * * Lynne M. Reder, Professor Department of Psychology Carnegie Mellon University Pittsburgh, PA 15213 phone: (412)268-3792 fax: (412) 268-2844 email: reder at cmu.edu URL: http://sands.psy.cmu.edu/ACT/people/reder.html From Luis.Botelho at iscte.pt Wed Dec 18 12:41:14 1996 From: Luis.Botelho at iscte.pt (Luis.Botelho at iscte.pt) Date: Wed, 18 Dec 1996 12:41:14 Subject: Working memory, short term memory, long term memory Message-ID: <199612181144.MAA23135@iscte.iscte.pt> 96/12/18 Dear ACT-R Users, my name is Luis and I work in the Computer Science Dept. of ISCTE, Lisbon, Portugal. I am not an ACT-R user, although I recently became a member of this mailing list. This message is not directly related to ACT but it also concerns cognitive science, namely working memory, short term memory and long term memory. If you feel this is not the appropriate place to this kind of discussion, please ignore this message and accept my apologies. I've developed a model of memory for autonomous artificial agents taking inspiration in cognition, namely in ACT and in the works of Robert Wyer and Thomas Srull, Allan Collins and Elizabeth Loftus, and Gordon Bower. The model is an hybrid model called SALT (Schema-Associative Long Term memory). SALT has two main components besides some temporary buffers: working memory and long term memory. Some time ago, Katia Sycara said that I'd better call short term memory to what I was calling long term memory. I would very much appreciate your comments on this matter. Please find bellow a short description of the SALT model. According to SALT, long term memory is an associative network with spreading activation. Each node contains a set of symbolic structures representing cognitive structures. These cognitive structures may be procedures, frames, condition- action rules, declarations, and the like. In the current implementation of the model, each of the mentioned cognitive structure is a Prolog clause. A node also contains a header that describes its contents. Headers are used in pattern-matching. Each time an external stimulus is put to the agent, the currently most activated node whose header matches the external stimulus receives some activation that spreads to the nodes to which it is associated. When the agent faces some problem, it searches its long term memory in decreasing order of activation and selects one or more nodes appropriate to solve the problem. The cognitive structures contained in the nodes selected are copied from long term memory to working memory. There, some form of symbolic processing takes place and a solution to the current problem is tried. If I understood correctly, Katia Sycara suggested that the component of SALT currently named Long Term Memory should be called Short Term Memory instead. What is your opinion? If you agree with her, then what is Long Term Memory? You may reply either to the ACT-R mailing list or to my own email address (see bellow). I thank you for your attention, Sincerely -- Luis ====================== Luis Miguel Botelho luis at iscte.pt Fax: 351-1-7964710 Phone: 351-1-7935000 Ext. 12411 Dept. de Ciencias e Tecnologias de Informacao do ISCTE Av. das Forcas Armadas, Edificio ISCTE 1600 Lisboa, Portugal