Proceedings of the Annual Meeting of the Cognitive Science Society

The production system formulation plays an important role in models of cognition. However, there do not exist neurally plausible realizations of production systems that can support fast and automatic processing of productions involving variables and n-ary relations. In this paper we show that the neurally plausible model for rapid reasoning over facts and rules involving n-ary predicates and variables proposed by Ajjanagadde and Shastri can be interpreted as such a production system. This interpretation is significant because it suggests neurally motivated constraints on the capacity of the working memory of a production system capable of fast parallel processing. It shows that a large number of rules — even those containing variables — may fire in parallel and a large number of facts may reside in the working memory, provided no predicate is instantiated more than a smaU number of times (% 3) and the number of distinct entities referenced by the