Proceedings of the Annual Meeting of the Cognitive Science Society

In their current functional form, ACT-R’s retrieval equations do not account for the left side of the RT-distance relation, that is, that as memory activation decreases, so does response time for retrieval failures. To accommodate this effect, I propose that the memory system uses the familiarity of the encoded object to gauge how much effort it should devote to retrieval. I quantify the degree of familiarity through the match score, which is the output of a global matching process. Familiarity, in turn, directly determines what the retrieval threshold should be. Adding a familiarity process orthogonal to recollection is in line with neuroimaging results, which uncover parallel familiarity and retrieval processes. The developments in this paper extend ACT-R’s memory theory into a dual process theory.