Vigilance: How to Do it and Who Should Do it

Abstract

The present laboratory study examined variables that are believed to impact vigilance in operational settings. First, instructions given to subjects were manipulated in order to impact their feelings of “command pressure” (Mackie, Wylie, & Smith, 1985). It was expected that instructions emphasizing detection efficiency would lead to increased subjective workload. Further, it was expected that decreasing instructional demands by emphasizing relaxing qualities of the task would not impact performance, though lower workload ratings were expected. In addition, response bias was manipulated by telling subjects to adopt either a conservative or a liberal criterion. Secondly, subjects' boredom proneness (BP) was measured to test the predictive validity of this measure in vigilance. All subjects monitored a VDT of uniform color for 30 min. They were asked to respond to 110 ms “long flickers” embedded in a matrix of 50 ms “short flickers” occurring at a rate of 15 per min. As expected, detection-emphasis subjects reported significantly higher workload. Overall performance regarding proportion of hits and A' was not impacted significantly by command emphasis, though an Emphasis x Bias interaction revealed that relaxation-liberal subjects performed more poorly than subjects in the remaining conditions. Finally, BP scores significantly predicted overall hits and A'. Results indicate that (1) much of what individuals find unpleasant about vigilance may lie with the demands implied by the initial instructions and (2) valid personality predictors of vigilance performance exist.