The effects of illumination, d-amphetamine, and methylphenidate upon vigilance performance of squirrel monkeys

The effects of illumination, d-amphetamine, and methylphenidate on vigilance behavior were studied with four squirrel monkeys. Detection rates of an auditory signal were higher in the light than in the dark. Although methylphenidate did not alter performance, d-amphetamine lowered detection rates more in the light than in the dark, particularly in male squirrel monkeys. Results were interpreted in terms of altered arousal levels. © 1980, The Psychonomic Society, Inc.. All rights reserved