Maintenance of Vigilance by Programmed Noise

Abstract

This research was designed to compare the relative effect of three environmental conditions on the performance of a simple vigilance task. The vigilance task consisted of a cathode ray tube display which was monitored by 30 Ss for 2 hr. Three environmental conditions were randomly introduced while S monitored the display. The conditions were a constant noise of 64.5 db, a variable noise having an average SPL of 64.5 db, and a quiet condition of 61 db. The results indicate that the probability of signal detection is higher for the variable noise condition than for the constant noise and quiet conditions. No difference in probability of detection was found between the latter two conditions. An explanation for the facilitating effect of sensory stimulation on vigilance is sought in terms of the alerting and general arousal effects attributed to the reticular activating system.