Cognitive architecture

A cognitive architecture can refer to a theory about the structure of the human mind. One of the main goals of a cognitive architecture is to summarize the various results of cognitive psychology in a comprehensive computer model. However, the results need to be in a formalized form so far that they can be the basis of a computer program. By combining the individual results are so for a comprehensive theory of cognition and the other a commercially usable model arise. Successful cognitive architectures include ACT-R (Adaptive Control of Thought, ACT), SOAR and OpenCog.

History

Nobel Laureate Herb Simon,^[1] one of the founders of the field of artificial intelligence, stated that the 1960 thesis by his student Ed Feigenbaum, EPAM^[2] provided a possible "architecture for cognition"^[3] because it included some commitments for how more than one fundamental aspect of the human mind worked. In EPAM's case, human memory and human learning.

John Anderson^[4] started research on human memory in the early 1970s and his 1973 thesis with Gordon Bower provided a theory of human associative memory.^[5] He included more aspects of his research on long-term memory and thinking processes into this research and eventually designed a cognitive architecture he eventually called ACT,^[6] He and his student used the term "cognitive architecture" in his lab to refer to the ACT theory as embodied in the collection of papers and designs since they didn't yet have any sort of complete implementation at the time.

The seminal work in this area is The Architecture of Cognition (1983).^[7] One can distinguish between the theory of cognition and the implementation of the theory. The theory of cognition outlined the structure of the various parts of the mind and made commitments to the use of rules, associative networks, and other aspects. The cognitive architecture implements the theory on computers. The software used to implement the cognitive architectures were also "cognitive architectures". Thus, a cognitive architecture can also refer to a blueprint for intelligent agents. It proposes (artificial) computational processes that act like certain cognitive systems, most often, like a person, or acts intelligent under some definition. Cognitive architectures form a subset of general agent architectures. The term 'architecture' implies an approach that attempts to model not only behavior, but also structural properties of the modelled system.

Distinctions

Cognitive architectures can be symbolic, connectionist, or hybrid. Some cognitive architectures or models are based on a set of generic rules, as, e.g., the Information Processing Language (e.g., Soar based on the unified theory of cognition, or similarly ACT-R). Many of these architectures are based on the-mind-is-like-a-computer analogy. In contrast subsymbolic processing specifies no such rules a priori and relies on emergent properties of processing units (e.g. nodes). Hybrid architectures combine both types of processing (such as CLARION). A further distinction is whether the architecture is centralized with a neural correlate of a processor at its core, or decentralized (distributed). The decentralized flavor, has become popular under the name of parallel distributed processing in mid-1980s and connectionism, a prime example being neural networks. A further design issue is additionally a decision between holistic and atomistic, or (more concrete) modular structure. By analogy, this extends to issues of knowledge representation.

In traditional AI, intelligence is often programmed from above: the programmer is the creator, and makes something and imbues it with its intelligence, though many traditional AI systems were also designed to learn (e.g. improving their game-playing or problem-solving competence). Biologically inspired computing, on the other hand, takes sometimes a more bottom-up, decentralised approach; bio-inspired techniques often involve the method of specifying a set of simple generic rules or a set of simple nodes, from the interaction of which emerges the overall behavior. It is hoped to build up complexity until the end result is something markedly complex (see complex systems). However, it is also arguable that systems designed top-down on the basis of observations of what humans and other animals can do rather than on observations of brain mechanisms, are also biologically inspired, though in a different way.

Some well-known cognitive architectures

• 4CAPS, developed at Carnegie Mellon University under Marcel A. Just
• ACT-R, developed at Carnegie Mellon University under John R. Anderson.
• ALifeE, developed under Toni Conde at the Ecole Polytechnique Fédérale de Lausanne.
• Apex developed under Michael Freed at NASA Ames Research Center.
• ASMO, developed under Rony Novianto at University of Technology, Sydney.
• CHREST, developed under Fernand Gobet at Brunel University and Peter C. Lane at the University of Hertfordshire.
• CLARION the cognitive architecture, developed under Ron Sun at Rensselaer Polytechnic Institute and University of Missouri.
• Copycat, by Douglas Hofstadter and Melanie Mitchell at the Indiana University.
• DUAL, developed at the New Bulgarian University under Boicho Kokinov.
• EPIC, developed under David E. Kieras and David E. Meyer at the University of Michigan.
• FORR developed by Susan L. Epstein at The City University of New York.
• GAIuS developed by Sevak Avakians.
• The H-Cogaff architecture, which is a special case of the CogAff schema. (See Taylor & Sayda, and Sloman refs below).
• CoJACK An ACT-R inspired extension to the JACK multi-agent system that adds a cognitive architecture to the agents for eliciting more realistic (human-like) behaviors in virtual environments.
• IDA and LIDA, implementing Global Workspace Theory, developed under Stan Franklin at the University of Memphis.
• OpenCog, an open-source implementation of reasoning, natural language processing, psi-theory and robotic control.
• PMML.1, Michael S. Gashler, University of Arkansas.
• PreAct, developed under Dr. Norm Geddes at ASI.
• PRODIGY, by Veloso et al.
• PRS 'Procedural Reasoning System', developed by Michael Georgeff and Amy Lansky at SRI International.
• Psi-Theory developed under Dietrich Dörner at the Otto-Friedrich University in Bamberg, Germany.
• R-CAST, developed at the Pennsylvania State University.
• Spaun (Semantic Pointer Architecture Unified Network) - by Chris Eliasmith at the Centre for Theoretical Neuroscience at the University of Waterloo - Spaun is a network of 2,500,000 artificial spiking neurons, which uses groups of these neurons to complete cognitive tasks via flexibile coordination. Components of the model communicate using spiking neurons that implement neural representations called “semantic pointers” using various firing patterns. Semantic pointers can be understood as being elements of a compressed neural vector space. ^[8]
• Soar, developed under Allen Newell and John Laird at Carnegie Mellon University and the University of Michigan.
• Society of mind and its successor the Emotion machine proposed by Marvin Minsky.
• Subsumption architectures, developed e.g. by Rodney Brooks (though it could be argued whether they are cognitive).
• QuBIC: Quantum and Bio-inspired Cognitive Architecture for Machine Consciousness developed by Wajahat M. Qazi and Khalil Ahmad at Department of Computer Science, GC University Lahore Pakistan and School of Computer Science, NCBA&E Lahore, Pakistan
• TinyCog a minimalist open-source implementation of a cognitive architecture based on the ideas of Scene Based Reasoning
• VisNet by Edmund Rolls at the Oxford Centre for Computational Neuroscience - A feature hierarchy model in which invariant representations can be built by self-organizing learning based on the temporal and spatial statistics of the visual input produced by objects as they transform in the world.^[9]

See also

References

External links

Media related to Cognitive architecture at Wikimedia Commons