Hopstaken Jesper F, van der Linden Dimitri, Bakker Arnold B, Kompier Michiel A J
Department of Work and Organizational Psychology, Institute of Psychology, Erasmus University Rotterdam, The Netherlands.
Department of Work and Organizational Psychology, Institute of Psychology, Erasmus University Rotterdam, The Netherlands.
Biol Psychol. 2015 Sep;110:100-6. doi: 10.1016/j.biopsycho.2015.06.013. Epub 2015 Jul 18.
Although mental fatigue is a complex, multi-facetted state that involves changes in motivation, cognition, and mood, one of its main characteristics is reduced task engagement. Despite its relevance for performance and safety, knowledge about the underlying neurocognitive processes in mental fatigue is still limited. Inspired by the idea that central norepinephrine plays an important role in regulating task engagement, we test a set of predictions that have been derived from recent studies that relate pupil dynamics to the levels of norepinephrine in the brain. Participants worked on a 2-back task for 2h while we used pupil measures to further explore the link between task engagement and the effects of mental fatigue. We hypothesized that baseline pupil diameter and stimulus-evoked pupil dilations decrease with increasing fatigue. Also, because previous studies have shown that the effects of fatigue are reversible by increasing the task rewards, we hypothesized that increasing the task rewards after 2h on the task would restore these pupil measures to pre-fatigue levels. While we did not find a decrease in baseline pupil diameter, we found that increasing mental fatigue coincided with diminished stimulus-evoked pupil dilation. Also, we confirmed that when sufficient rewards were presented to a fatigued individual, the pupil dilations could be restored. This supports the view that motivational factors are important in predicting engagement versus disengagement during fatigue.
尽管精神疲劳是一种复杂的、多方面的状态，涉及动机、认知和情绪的变化，但其主要特征之一是任务参与度降低。尽管精神疲劳与绩效和安全相关，但关于其潜在神经认知过程的知识仍然有限。受中枢去甲肾上腺素在调节任务参与度中起重要作用这一观点的启发，我们检验了一组从近期研究中得出的预测，这些研究将瞳孔动态与大脑中去甲肾上腺素水平联系起来。参与者进行了2小时的2-back任务，同时我们使用瞳孔测量来进一步探索任务参与度与精神疲劳影响之间的联系。我们假设随着疲劳程度的增加，基线瞳孔直径和刺激诱发的瞳孔扩张会减小。此外，由于先前的研究表明，通过增加任务奖励可以逆转疲劳的影响，我们假设在任务进行2小时后增加任务奖励会使这些瞳孔测量值恢复到疲劳前的水平。虽然我们没有发现基线瞳孔直径减小，但我们发现精神疲劳程度的增加与刺激诱发的瞳孔扩张减小同时出现。此外，我们证实，当向疲劳个体提供足够的奖励时，瞳孔扩张可以恢复。这支持了动机因素在预测疲劳期间参与与脱离方面很重要的观点。
