Automated behavioral procedures for infant monkeys.
A method is described for testing infant monkeys on a variety of operant tasks as soon as they can self-feed, typically within the first week of life. Each infant was housed during the 16-21-hour experimental session in a cage to which operant behavioral equipment was attached. Computer control of the experimental contingencies and data acquisition allowed a relatively large number of monkeys to be tested simultaneously, as well as detailed analysis of response parameters. Infant monkeys are capable of learning a number of tasks that assess learning and memory, including visual discrimination and reversal, simultaneous discrimination, and spatial and nonspatial matching to sample. Infant monkeys also perform like older animals on intermittent schedules of reinforcement. The long experimental sessions allowed determination of feeding pattern over the course of the night. Analyses of these variables have proved sensitive to the effects of developmental exposure to neurotoxicants such as lead and caffeine.