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.

As a first step towards applying ACT-R to problems of like-lihood judgment, we draw parallels between ACT-R and Hy-Gene. More specifically, in the spirit of theory integration, wedemonstrate the relation between ACT-R’s declarative memorysystem and the core of HyGene: Minerva2. We first start bytransforming ACT-R’s activation equations into what is in ourview a more intuitive form. This form then allows us to moretransparently see the correspondence of the effect of prior his-tory between the two theories and of the current context be-tween them. The results provide insights into the workings ofthe two theories and open an avenue for future attempts of the-ory integration, not only between the two theories, but also torelated theories of memory. Moreover, we hope these resultswill be important steps toward testing ACT-R’s capabilities ofaccounting for judgment phenomena.

Skill acquisition studies have generally focused on individual tasks, such as language learning, learning how to use a texteditor or how to play video games. Here we present a study that investigates how subjects learn to work in a team in adynamic collaborative task. The task - Coop Space Fortress - is a modification of a computer game used extensively inresearch, in which subjects fly space ships in a frictionless environment and coordinate to destroy a space fortress. Whenlearning to play this computer game, subjects not only master the game controls, but also typically settle on team roles tomore efficiently achieve their goal, despite not being allowed to communicate.

We present the project aimed at creating a database of detailed architectural process models of memory-based decision models. Those models are implemented in the cognitive architecture ACT-R. In creating this database, we have identified commonalities and differences of various decision models in the literature. The model database can provide insights into the interrelation among decision models and can be used in future research to address debates on inferences from memory, which are hard to resolve without specifying the processing steps at the level of precision that a cognitive architecture provides.