Extending the Influence of Contextual Information in ACT-R using Buffer Decay

Date

2014

Journal Title

Journal ISSN

Volume Title

Publisher

Cognitive Science Society

Abstract

In this paper, we describe an extension of the theory of short term memory decay for the ACT-R cognitive architecture. By including a short-term decay for elements recently cleared from active memory, we have extended the functionality of spreading activation as a source of implicit contextual information for the model. In ACT-R models of serial memory and decision-making, contextual information has generally been modeled using either explicit markers (eg, positional indices) or fixed-length windows of prior elements (eg, a lag-based representation). While markers and fixed length windows do capture some patterns of human errors, they are inflexible, are set by the modeler and not the model, and are not psychologically-plausible representations of contextual information. In conjunction with our associative learning mechanism (Thomson & Lebiere, 2013), we show how buffer decay can provide more flexible and implicit contextual information which explains refraction, positional confusion errors, and repetition facilitation and inhibition.

Description

Keywords

cognitive architecture, memory, context, ACT-R, working memory, decay

Citation

Thomson, R., Bennati, S., & Lebiere, C. (2014). Extending the influence of contextual information in ACT-R using buffer decay. In Proceedings of the annual meeting of the cognitive science society (Vol. 36, No. 36).

DOI