How Stress and Mental Workload are Connected

Mental Workload (MWL) can be both good and bad; we can thrive under high MWL, or our performance can drop if the demands become either too low or too high. Similarly, stress is not always bad, short term stress can be beneficial to overcome a challenge or dangerous situation. In our research, we have seen both people that enjoy high workload, and people that feel stressed by it, but we do not know whether that experience of stress significantly affects our measurements. Our recent results show that fNIRS measurements are affected by stress (measured by SSSQ). This paper seeks to discuss the relationship between these concepts, discussing examples of where similar influencing factors appear within models of both Stress and Mental Workload, as well as within subjective measures of them. We conclude that future work must consider participants' experiences of both Stress and Mental Workload, as well as other cognitive concepts, when trying to estimate them from physiological measures.