Psychophysiological cueing and the vigilance decrement function

Abstract

Vigilance is the mental capacity by which observers maintain their attention across time. It is most commonly operationalized as the ability to detect rare and critical signals. Due to inherent constraints in human processing capacities, the longer one expects an observer to keep watch, the more likely it is that a searched-for signal will be missed. Consequently, without some means of computer or automation-based assistance, failures in operator vigilance are likely to occur. Mackworth called this characteristic decline in performance over time the ‘vigilance decrement.’ Many modern-day operational tasks that entail life-or-death consequences require vigilant monitoring, mostly of visual stimuli. Consequently, it is unsurprising that research has sought to establish and validate methods of counteracting such an adverse behavioral trend. One such strategy is cueing. Cuing provides the operator with a reliable prompt concerning signal onset probability. Traditional protocols have based such cues on task-related or environmental factors. The present work addresses the methodological concerns of using cues based on these factors in the design of effective vigilance cueing systems. This present work proposes an alternative perspective supported by empirical research to explore and validate this novel approach. This study examines the efficacy of cueing when based on an operator’s psychophysiological state (i.e., cortical blood oxygenation) in a novel vigilance task incorporating dynamic rather than static visual displays. Results pertaining to performance outcomes, physiological measures (heart rate variability), and perceived workload and stress are interpreted via Signal Detection Theory and the Resource Theory of vigilance.