Haubert Ashley, Walsh Matt, Boyd Rachel, Morris Megan, Wiedbusch Megan, Krusmark Mike, Gunzelmann Glenn
Sensor Systems Division, Human Factors Group, University Research Institute, Dayton, OH, United States.
RAND Corporation, Santa Monica, CA, United States.
Front Psychol. 2018 Mar 6;9:237. doi: 10.3389/fpsyg.2018.00237. eCollection 2018.
Cognitive fatigue emerges in wide-ranging tasks and domains, but traditional vigilance tasks provide a well-studied context in which to explore the mechanisms underlying it. Though a variety of experimental methodologies have been used to investigate cognitive fatigue in vigilance, relatively little research has utilized electroencephalography (EEG), specifically event-related potentials (ERPs), to explore the nature of cognitive fatigue, also known as the vigilance decrement. Moreover, much of the research that has been done on vigilance and ERPs uses non-traditional vigilance paradigms, limiting generalizability to the established body of behavioral results and corresponding theories. In this study, we address concerns with prior research by (1) investigating the vigilance decrement using a well-established visual vigilance task, (2) utilizing a task designed to attenuate possible confounding ERP components present within a vigilance paradigm, and (3) informing our interpretations with recent findings from ERP research. We averaged data across electrodes located over the frontal, central, and parietal scalp. Then, we generated waveforms locked to the onset of critical low-frequency or non-critical high-frequency events during a 40 min task that was segregated into time blocks for data analysis. There were three primary findings from the analyses of these data. First, mean amplitude of N1 was greater during later blocks for both low-frequency and high-frequency events, a contradictory finding compared to past visual vigilance studies that is further discussed with respect to current interpretations of the N1 in visual attention tasks. Second, P3b mean amplitude following low-frequency events was reduced during later blocks, with a later onset latency. Third and finally, the decrease in P3b amplitude correlated with individual differences in the magnitude of the vigilance decrement, assessed using '. The results provide evidence for degradations of cognitive processing efficiency brought on by extended time on task, leading to delayed processing and decreased discriminability of critical stimuli from non-critical stimuli. These conclusions are discussed in the context of the vigilance decrement and corresponding theoretical accounts.
认知疲劳出现在广泛的任务和领域中，但传统的警觉任务提供了一个经过充分研究的背景，便于探究其潜在机制。尽管已经使用了多种实验方法来研究警觉任务中的认知疲劳，但相对较少的研究利用脑电图（EEG），特别是事件相关电位（ERP）来探究认知疲劳（也称为警觉下降）的本质。此外，许多关于警觉和ERP的研究使用的是非传统的警觉范式，限制了其对既定行为结果和相应理论的普遍适用性。在本研究中，我们通过以下方式解决先前研究中存在的问题：（1）使用成熟的视觉警觉任务来研究警觉下降；（2）利用一个旨在减少警觉范式中可能存在的混淆ERP成分的任务；（3）用ERP研究的最新发现来指导我们的解释。我们对位于额部、中央和顶叶头皮上的电极数据进行平均。然后，我们在一个40分钟的任务中生成锁定在关键低频或非关键高频事件开始时的波形，该任务被划分为时间块进行数据分析。对这些数据的分析有三个主要发现。首先，对于低频和高频事件，N1的平均振幅在后期块中更大，这一发现与过去的视觉警觉研究相矛盾，将在视觉注意任务中N1的当前解释方面进一步讨论。其次，低频事件后的P3b平均振幅在后期块中降低，且起始潜伏期延迟。第三也是最后一点，P3b振幅的降低与警觉下降幅度的个体差异相关，使用“.”进行评估。结果为任务时间延长导致的认知处理效率下降提供了证据，导致关键刺激与非关键刺激的处理延迟和可辨别性降低。这些结论将在警觉下降和相应理论解释的背景下进行讨论。
