The Effects of Caffeine on Performance and Stress in an Abbreviated Vigilance Task

Abstract

Recently, Temple, Warm, Dember, LaGrange, & Matthews (1996) described a 12-min computerized vigilance task which duplicates the vigilance decrement and the workload (NASA-TLX) and stress characteristics (Dundee Stress State Questionnaire) of vigils lasting 30 min or more. The abbreviated task may be useful in situations wherein long-duration tasks are precluded, e.g., performance assessment batteries, neuropsychological testing, and brain imaging. The present experiment extended this line of investigation by demonstrating that performance on the abbreviated task is enhanced (signal detections were increased and the decrement attenuated) by caffeine — a drug which benefits long-duration vigilance tasks. The enhancement effect associated with caffeine was limited to performance, however, suggesting that the drug influences factors which control signal detection but not those which control task-induced stress.