A Formal Semantics for the Cognitive Architecture ACT-R
The cognitive architecture ACT-R is very popular in cognitive sciences. It merges well-investigated results of psychology to a unified model of cognition. This enables researchers to implement and execute domain-specific cognitive models. ACT-R is implemented as a production rule system. Although its underlying psychological theory has been investigated in many psychological experiments, ACT-R lacks a formal definition from a mathematical-computational point of view.
In this paper, we present a formalization of ACT-R’s fundamental concepts including an operational semantics of the core features of its production rule system. The semantics abstracts from technical artifacts of the implementation. Due to its abstract formulation, the semantics is eligible for analysis. To the best of our knowledge, this operational semantics is the first of its kind.
Furthermore, we show a formal translation of ACT-R production rules to Constraint Handling Rules (CHR) and prove soundness and completeness of the translation mechanism according to our operational semantics.
KeywordsComputational psychology Cognitive systems ACT-R Production rule systems Constraint handling rules Operational semantics
- 5.Bistarelli, S., Frühwirth, T., Marte, M.: Soft constraint propagation and solving in CHRs. In: Proceedings of the 2002 ACM symposium on Applied computing. pp. 1–5. ACM (2002)Google Scholar
- 6.Bothell, D.: ACT-R 6.0 Reference Manual - Working Draft. Department of Psychology, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213Google Scholar
- 8.Frühwirth, T.: Constraint Handling Rules. Cambridge University Press, Cambridge (2009)Google Scholar
- 10.Gall, D.: A rule-based implementation of ACT-R using Constraint Handling Rules. Master Thesis, Ulm University (2013)Google Scholar
- 12.Taatgen, N.A., Lebiere, C., Anderson, J.: Modeling paradigms in ACT-R. Cognition and Multi-Agent Interaction: From Cognitive Modeling to Social Simulation. Cambridge University Press, Cambridge (2006) Google Scholar