Sustained Attention Task Example

Sustained attention became a subject of study in World War II. British radar operators, after being on duty for 30 minutes, were observed failing to detect critical signals. Radar had been only recently developed and required operators to attend to a dim, small screen for very infrequent, but important events. Mackworth, who performed the first research in this area, defined vigilance as, "a state of readiness to detect and respond to certain small changes occurring at random time intervals in the environment." Typically, lapses in vigilance are evidenced by detection of fewer targets and increases in response time.*

Vigilance decrement impacts human performance in everyday life, as well as, within complex systems. There are many adverse influences on sustained attention. Fatigue, sleep deprivation, and circadian rhythm disruption are among the foremost. Also, Vigilance is adversely impacted by stress, noise, workload (high or low), emotional state, extreme temperatures, and other environmental stressors.*

Display Monitoring for Infrequent, Critical Events Can Lead to Vigilance Decrement

Research has shown there are several ways to combat vigilance decrements such as using targets that readily stand-out from background, using random alerting auditory signals, providing feedback on performance and designing tasks that have neither too low or too high work load demands.*

*Wickens, C.D., Mavor, A.S. & McGee, J.P. (eds), Flight to the Future: Human Factors in Air Traffic Control (1997), National Research Academy of Sciences, National Academies Press, Washington DC.