Department of Psychological and Brain Sciences, Washington University in Saint Louis, St. Louis, Missouri, USA.
Department of Otolaryngology, Washington University in Saint Louis, St. Louis, Missouri, USA.
Psychophysiology. 2023 Jul;60(7):e14256. doi: 10.1111/psyp.14256. Epub 2023 Feb 3.
Pupillometry has a rich history in the study of perception and cognition. One perennial challenge is that the magnitude of the task-evoked pupil response diminishes over the course of an experiment, a phenomenon we refer to as a fatigue effect. Reducing fatigue effects may improve sensitivity to task effects and reduce the likelihood of confounds due to systematic physiological changes over time. In this paper, we investigated the degree to which fatigue effects could be ameliorated by experimenter intervention. In Experiment 1, we assigned participants to one of three groups-no breaks, kinetic breaks (playing with toys, but no social interaction), or chatting with a research assistant-and compared the pupil response across conditions. In Experiment 2, we additionally tested the effect of researcher observation. Only breaks including social interaction significantly reduced the fatigue of the pupil response across trials. However, in all conditions we found robust evidence for fatigue effects: that is, regardless of protocol, the task-evoked pupil response was substantially diminished (at least 60%) over the duration of the experiment. We account for the variance of fatigue effects in our pupillometry data using multiple common statistical modeling approaches (e.g., linear mixed-effects models of peak, mean, and baseline pupil diameters, as well as growth curve models of time-course data). We conclude that pupil attenuation is a predictable phenomenon that should be accommodated in our experimental designs and statistical models.
瞳孔测量在感知和认知研究中有着悠久的历史。一个长期存在的挑战是，任务诱发的瞳孔反应的幅度在实验过程中会减弱，这种现象我们称之为疲劳效应。减少疲劳效应可以提高对任务效应的敏感性，并减少由于随时间系统的生理变化而导致的混淆的可能性。在本文中，我们研究了通过实验者干预可以在多大程度上减轻疲劳效应。在实验 1 中，我们将参与者分配到三个组之一：不休息、运动休息（玩玩具，但没有社交互动）或与研究助理聊天，并比较了不同条件下的瞳孔反应。在实验 2 中，我们还测试了研究人员观察的效果。只有包括社交互动的休息才能显著减轻整个试验过程中瞳孔反应的疲劳。然而，在所有条件下，我们都发现了疲劳效应的有力证据：也就是说，无论协议如何，任务诱发的瞳孔反应在实验过程中都会大大减弱（至少 60%）。我们使用多种常见的统计建模方法（例如，峰值、平均值和基线瞳孔直径的线性混合效应模型，以及时间过程数据的生长曲线模型）来解释我们的瞳孔测量数据中的疲劳效应的差异。我们得出结论，瞳孔衰减是一种可预测的现象，应该在我们的实验设计和统计模型中加以考虑。
