One central topic in ergonomics and human-factors research is the assessment of mental workload. Heart rate and heart rate variability are common for registering mental workload. However, a major problem of workload assessment is the dissociation among different workload measures. One potential reason could be the disregard of their inherent timescales and the interrelation between participants’ individual differences and timescales. The aim of our study was to determine if different cardiovascular biomarkers exhibit different timescales. We focused on air traffic controller and investigated biomarkers’ ability to distinguish between conditions with different load levels connected to prior work experience and different time slots. During an interactive real-time simulation, we varied the load situations with two independent variables: the traffic volume and the occurrence of a priority-flight request. Dependent variables for registering mental workload were the heart rate and heart rate variability from two time slots. Our results show that all cardiovascular biomarkers were sensitive to workload differences with different inherent timescales. The heart rate responded sooner than the heart rate variability features from the frequency domain and it was most indicative during the time slot immediately after the priority-flight request. The heart rate variability parameters from the frequency domain responded with latency and were most indicative during the subsequent time slot. Furthermore, by consideration of biomarkers’ inherent timescales, we were able to assess a significant effect of work experience on heart rate and mid/high frequency-band ratio of the heart rate variability. Results indicated that different cardiovascular biomarkers reveal different inherent timescales.

人体工程学和人为因素研究的中心主题之一是脑力负荷的评估。心率和心率变异性对于记录脑力负荷很常见。然而，工作量评估的一个主要问题是不同工作量指标之间的分离。一个潜在的原因可能是忽视了他们固有的时间尺度以及参与者的个体差异和时间尺度之间的相互关系。我们研究的目的是确定不同的心血管生物标志物是否表现出不同的时间尺度。我们专注于空中交通管制员，并研究了生物标志物区分与先前工作经验和不同时间段相关的不同负载水平的条件的能力。在交互式实时模拟过程中，我们使用两个自变量来改变负载情况：交通量和优先航班请求的发生。记录脑力负荷的因变量是两个时间段的心率和心率变异性。我们的结果表明，所有心血管生物标志物对不同固有时间尺度的工作负荷差异敏感。心率的响应比频域的心率变异性特征更快，并且在优先飞行请求之后的时隙内最具指示性。频域的心率变异性参数有延迟响应，并且在随后的时隙内最具指示性。此外，通过考虑生物标志物的固有时间尺度，我们能够评估工作经验对心率和心率变异性的中/高频段比率的显着影响。 结果表明，不同的心血管生物标志物揭示了不同的固有时间尺度。