Two ACT-R papers

[Niels Taatgen]

At the last ACT-R workshop, people agreed that it would be a good idea
to announce new ACT-R papers on the mailing list. Unfortunately, this is
hardly ever put into practice. Therefore, I want to announce two papers
that Linda Jongman and I have submitted to the cognitive science
conference. These papers can be retrieved from the web from
http://tcw2.ppsw.rug.nl/prepublications/

An ACT-R model of individual differences in changes
in adaptivity due to mental fatigue
Linda Jongman and Niels Taatgen
Abstract:
In this paper we show that adaptivity is reduced when people become
fatigued. Fatigued people adapt worse to changing probability
distributions as compared to non-fatigued individuals. In an ACT-R model
of the task we show that this decreased adaptivity is due to a decrease
in the use of one specific strategy. We argue that the use of this
strategy is decreased, because it places high demands on working memory.
In previous research we also found indications that mental fatigue is
related to changes in working memory functioning. We argue that modeling
individual differences in performance will provide better insight in the
processes involved in mental fatigue.

A model of learning task-specific knowledge for a new task
Niels Taatgen
Abstract:
In this paper I will present a detailed ACT-R model of how the
task-specific knowledge for a new, complex task is learned. The model is
capable of acquiring its knowledge through experience, using a
declarative representation that is gradually compiled into a procedural
representation. The model exhibits several characteristics that concur
with Fitts theory of skill learning, and can be used to show that
individual differences in working memory capacity initially have a large
impact on performance, but that this impact diminished after sufficient
experience. Some preliminary experimental data support these findings.
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Niels Taatgen
Technische Cognitiewetenschap/Cognitive science & engineering
Grote Kruisstraat 2/1, 9712 TS Groningen, Netherlands
050-3636435 / +31503636435
niels at tcw2.ppsw.rug.nl  http://tcw2.ppsw.rug.nl/~niels
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