Data_Sheet_1_Objective Assessments of Mental Fatigue During a Continuous Long-Term Stress Condition.docx

Prolonged periods of cognitive workload will cause mental fatigue, but objective, quantitative, and sensitive measurements that reflect long-term, stress-induced mental fatigue have yet to be elucidated. This study aims to apply a potential marker of Rényi entropy to investigate the mental fatigue changes in a long-term, high-level stress condition and compare three different instruments for assessment of mental fatigue: EEG, the oddball task, and self-scoring. We recruited nine individuals who participated in a 5-day intellectually challenging competition. The participants were assessed for mental fatigue each day of the competition using prefrontal cortex electroencephalogram (EEG). Reaction time in an oddball task and self-rated scoring were used comparatively to evaluate the performance of the EEG. Repeated measures ANOVA was utilized to analyze the differences among score, reaction time, and wavelet Rényi entropy. The results demonstrated that both wavelet Rényi entropy extracted from EEG and self-rated scoring revealed significant increases in mental fatigue during the 5 days of competition (P < 0.001). The reaction time of the oddball task did not show significant changes during the five-day competition (P = 0.066). Moreover, the wavelet Rényi entropy analysis of EEG showed greater sensitivity than the self-rated scoring and reaction time of the oddball task for measuring mental fatigue changes. In conclusion, this study shows that mental fatigue accumulates during long-term, high-level stress situations. The study also indicates that EEG wavelet Rényi entropy is an efficient metric to reflect the change of mental fatigue under a long-term stress condition and that EEG is a better method to assess long-term mental fatigue.

长期认知负荷会引发精神疲劳，但目前仍缺乏能够精准反映长期应激诱导精神疲劳的客观、定量且灵敏的测量手段。本研究旨在借助一种潜在标记物——雷尼熵（Rényi entropy），探究长期高应激状态下的精神疲劳变化规律，并对比三种精神疲劳评估工具：脑电图（electroencephalogram, EEG）、oddball任务与自我评分量表。本研究招募了9名参与为期5天高智力负荷竞赛的受试者，竞赛期间每日均通过前额叶皮层脑电图（EEG）对受试者的精神疲劳状态进行评估；同时采用oddball任务反应时与自我评分量表，对比验证脑电图（EEG）的评估效能。本研究采用重复测量方差分析对自我评分、oddball任务反应时与小波雷尼熵（wavelet Rényi entropy）三项指标的差异进行分析。结果显示，从脑电图（EEG）中提取的小波雷尼熵与自我评分量表均表明，竞赛5天期间受试者的精神疲劳程度显著上升（P < 0.001）；而oddball任务的反应时在5天竞赛期间未出现显著变化（P = 0.066）。此外，脑电图小波雷尼熵分析在监测精神疲劳变化方面，相较自我评分量表与oddball任务反应时具有更高的灵敏度。综上，本研究证实长期高应激状态下精神疲劳会逐渐累积；同时表明，脑电图小波雷尼熵是反映长期应激下精神疲劳变化的有效指标，而脑电图（EEG）亦是评估长期精神疲劳的更优方法。