Modeling optimal arousal by integrating basic cognitive components

Mind-wandering occurs as emotional arousal decreases, which is related to the level of mastery of the current task. As a worker becomes more proficient in a task, the cognitive resources required to perform the task decrease. Then, surplus resources emerge and are naturally directed to “default-mode thinking,” which people usually engage in outside the task. As mind-wandering continues, this default-mode thinking becomes more active and affects the task performance. In this study, we describe this process by combining the basic functions of the cognitive architecture Adaptive Control of Thought-Rational (ACT-R). The chunk activation mechanism represents the on- and off-task thinking loops. Furthermore, we introduce stochastic fluctuation in the chunk activation to change the transition probability between these loops. This fluctuation is assumed to be driven by parasympathetic activity, which increases over time and is suppressed by novel stimuli. To develop this physiological change, this study uses the ACT-R temporal module. Simulations using these modules demonstrate the inverse U-shaped relations between task performance and task continuation. Such a process is consistent with theories of optimal levels of arousal.