Cognitive Architectures For Conceptual Structures John F. Sowa VivoMind Research, LLC Abstract. The book Conceptual Structures: Information Processing in Mind and Machine surveyed the state of the art in artificial intelligence and cognitive science in the early 1980s and outlined a cognitive architecture as a foundation for further research and development. The basic ideas stimulated a broad range of research that built on and extended the original topics. This paper reviews that architecture and compares it to four other cognitive architectures with their roots in the same era: Cyc, Soar, Society of Mind, and Neurocognitive Networks. The CS architecture has some overlaps with each of the others, but it also has some characteristic features of its own: a foundation in Peirce’s logic and semiotics; a grounding of symbols in Peirce’s twin gates of perception and action; and a treatment of logic as a refinement and extension of more primitive mechanisms of language and reasoning. The concluding section surveys the VivoMind Cognitive Architecture, which implements and extends the CS architecture. This is a slightly revised version of a paper in Proc. 19th International Conference on Conceptual Structures, edited by S. Andrews, S. Polovina, R. Hill, & B. Akhgar, LNAI 6828, Heidelberg: Springer, 2011, pp. 35-49. 1. Cognitive Architectures A cognitive architecture is a design for a computational system for simulating some aspect of human cognition. During the past half century, dozens of cognitive architectures have been proposed, implemented, and compared with human performance (Samsonovich 2010). The book Conceptual Structures (Sowa 1984) surveyed the state of the art in the early 1980s and proposed a design that has stimulated a broad range of research and development projects. After more than a quarter century, it’s time to review the progress in terms of recent developments in cognitive science, artificial intelligence, and computational linguistics. To provide perspective, it’s useful to review some related architectures that have also been under development for a quarter century or more: Cyc, Soar, Society of Mind, and Neurocognitive Networks. The Cyc project, whose name comes from the stressed syllable of encyclopedia, was chartered in 1984 as an engineering project. It placed a higher priority on computational efficiency than simulating psycholinguistic theories. The technical foundation was based on the previous decade of research on knowledge-based systems (Lenat & Feigenbaum 1987): • Lenat estimated that encyclopedic coverage of the common knowledge of typical high-school graduates would require 30,000 articles with about 30 concepts per article, for a total of about 900,000 concepts. • The Japanese Electronic Dictionary Research Project (EDR) estimated that the knowledge of an educated speaker of several languages would require about 200K concepts represented in each language. • Marvin Minsky noted that less than 200,000 hours elapses between birth and age 21. If each person adds four new concepts per hour, the total would be less than a million.