Maintaining the Level of Vigilance by Means of Knowledge of Results About a Secondary Vigilance Task

An experiment is reported in which performance of a central vigilance task was maintained at a high level by giving knowledge of results concerning performance on a peripheral vigilance task which was undertaken concurrently. Knowledge of results consisted of displaying response time to the onset of a signal in the secondary task, response time connoting the degree of alertness with respect to the central task. There appear to be implications for the design of an alertness indicator.