Vigilance is the action or state of keeping careful watch for possible danger or difficulties. The issue with this is that as automation is becoming increasingly more prevalent within our society humans are having to switch from the active role of operator to the passive role of monitor.
Human Factors research has identified many issues with requiring humans to do vigilance tasks as they are highly stressful on individuals because of their substantial demand on information processing resources. One reason for this is individuals need to constantly use working memory to distinguish what a threating detection is compared to a non-threatening detection.
Additionally, many experiments have measured workload during vigilance tasks. The results show that vigilance tasks carry high workload and are cognitively demanding. It is also found that vigilance decrement steadily increases as workload increases over time. Other studies show that there is a reduction in cerebral flow during vigilance tasks which provides physiological evidence that performance capabilities decrease during vigilance tasks.
Research has investigated the high stress that results from vigilance tasks. Data indicates that increases in epinephrine and norepinephrine, as well as self-reports of various experiments showing vigilance tasks cause individuals to disengage from the task and experience distress and worry.