The effects of signal salience and caffeine on performance, workload, and stress in an abbreviated vigilance task

Hum Factors. 2000 Summer;42(2):183-94. doi: 10.1518/001872000779656480.


In 2 experiments, a 12-min computerized vigilance task was demonstrated to reproduce the vigilance decrement, high workload (NASA-TLX), and stressful character (Dundee Stress State Questionnaire) of vigilance tasks lasting 30 min or more. In Experiment 1, the abbreviated task was also shown to duplicate the signal salience effect, a major finding associated with long-duration vigilance tasks. Moreover, Experiment 2 showed that performance on the abbreviated task can be enhanced by caffeine - a drug that benefits long-duration tasks. This enhancement effect was limited to performance, however, suggesting that caffeine influences factors that control signal detection but not those that control task-induced stress. The results parallel those obtained with long-duration tasks and support a resource-depletion model of the vigilance decrement. The abbreviated task might be useful in situations in which long-duration tasks are precluded (e.g., performance assessment batteries, neuropsychological testing, and brain imaging).

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Attention* / drug effects
  • Caffeine / pharmacology*
  • Central Nervous System Stimulants / pharmacology*
  • Female
  • Humans
  • Male
  • Signal Detection, Psychological*
  • Stress, Physiological* / etiology
  • Task Performance and Analysis*
  • Time Factors
  • Workload*


  • Central Nervous System Stimulants
  • Caffeine