A vigilance task sensitive to the effects of stimulants, hypnotics, and environmental stress: The Scanning Visual Vigilance Test

The Scanning Visual Vigilance Test is a variable-length detection test designed to assess the ability of individuals to maintain visual alertness for sustained periods of time. The test was designed to be sensitive to changes in vigilance produced by subtle variations in performance, such as those produced by low doses of centrally acting food constituents, drugs, or environmental stress. The test has been shown to be sensitive to the effects of stimulants and sedatives, as well as cold stress and sleep loss. It requires the subject to continuously scan a video monitor to detect the occurrence of infrequent stimuli that are difficult to detect. The number of stimuli correctly detected, false alarms, and reaction times are recorded. The stimulus is a small rectangle displayed for 2 sec at random locations on a darker region of a video monitor at random or pseudo-random times. The brightness of the stimulus can be adjusted for each subject individually on an automated threshold detection test. Training and test session length are defined by the experimenter. Hardware requirements are an IBM-compatible personal computer (286 or higher) with a color or grayscale VGA monitor.