An ACT-R Model of Individual Differences in Changes in Adaptivity due to Mental Fatigue

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.