Copycat is a model of analogy making and human cognition based on the concept of the parallel terraced scan, developed by Douglas Hofstadter, Melanie Mitchell, and others at the at Center for Research on Concepts and Cognition, Indiana University Bloomington. The original Copycat was written in a now defunct version of Common Lisp; however, a modern Java port exists. The term cognitive model can have basically two meanings. ... Analogy is both the cognitive process of transferring information from a particular subject (the analogue or source) to another particular subject (the target), and a linguistic expression corresponding to such a process. ... Look up Cognition in Wiktionary, the free dictionary. ... The parallel terraced scan is a multi-agent based search technique that is basic to cognitive architectures, such as Copycat, Letter-string, the Examiner, Tabletop, and others. ... Douglas Richard Hofstadter (born February 15, 1945 in New York, New York) is an American academic. ... Melanie Mitchell is a scientist who has worked at the Santa Fe Institute and Los Alamos National Laboratory. ... Indiana University is the principal campus of the Indiana University system. ... Common Lisp, commonly abbreviated CL, is a dialect of the Lisp programming language, published in ANSI standard X3. ...

Description

Copycat produces answers to such problems as "abc is to abd as xyz is to what?" (abc:abd :: xyz:?). Hofstadter and Mitchell consider analogy making as the core of high-level cognition, or high-level perception, as Hofstadter calls it, basic to recognition and categorization. High-level perception emerges from the spreading activity of many independent processes, called codelets, running in parallel, competing or cooperating. They create and destroy temporary perceptual constructs, probabilistically trying out variations to eventually produce an answer. The codelets rely on an associative network, slipnet, built on pre-programmed concepts and their associations (a long-term memory). The changing activation levels of the concepts make a conceptual overlap with neighboring concepts. A termite cathedral mound produced by a termite colony: a classic example of emergence in nature. ... Long-term memory (LTM) is memory, stored as meaning, that can last as little as 30 seconds or as long as decades. ...

Copycat's architecture is tripartite, consisting of a slipnet, a working area (also called workspace, similar to blackboard systems), and the coderack (with the codelets). The slipnet is a network comprised of nodes, which represent permanent concepts, and links, which are relations, between them. The codelets increase activations in the slipnet, and build structures, based on the associations there, in the working area. Workspace is a term used in computer programming. ... A blackboard system in computer science is a type of Artificial Intelligence application based on the blackboard architectural model. ...

Comparison to other cognitive architectures

Copycat differs considerably in many respects from other cognitive architectures such as ACT-R, Soar, DUAL, Psi, or subsumption architectures. A cognitive architecture is a blueprint for intelligent agents. ... ACT-R (pronounced act-ARE: Adaptive Control of Thought--Rational) is a cognitive architecture mainly developed by John R. Anderson at Carnegie Mellon University. ... Soar (also known as SOAR) is a symbolic cognitive architecture, created by John Laird, Allen Newell, and Paul Rosenbloom at Carnegie Mellon University. ... DUAL ia a general cognitive architecture integrating the connectionist and symbolic approaches at the micro level. ... Subsumption architecture is an AI concept originating from behavior based robotics. ...

Copycat is Hofstadter's most popular model. Other models presented by Hofstadter et al. are similar in architecture, but different in the so-called microdomain, their application, e.g. Letter Spirit, etc.

Since the 1995 FARG book, work on Copycat-like models has continued: as of 2007 the latest models are Metacat (a self-watching version) and SeekWell, a music cognition model. The architecture is known as the "FARGitecture" and current implementions use a variety of modern languages including C# and Java. A current FARG project is to build a single generic FARGitecture framework, Magnificat, that can be reused easily.

References

• Mitchell, Melanie. Analogy-Making as Perception. ISBN 0-262-13289-3 (hardback).  (1993)
• Hofstadter, Douglas R.. Fluid Concepts and Creative Analogies. ISBN 0-465-02475-0 (paperback), ISBN 0-465-05154-5 (hardback). 

Melanie Mitchell is a scientist who has worked at the Santa Fe Institute and Los Alamos National Laboratory. ... Douglas Richard Hofstadter (born February 15, 1945) is an American academic. ... This page is a candidate for speedy deletion. ...

External links

• A short description of Copycat
• The Copycat Project: A Model of Mental Fluidity and Analogy-Making (pdf)
• How to get the source code