Effects of Food Deprivation on Free-Operant Avoidance

Abstract

2 marmoset monkeys were exposed to a schedule of continuous avoidance on which each response postponed for 30-sec. shock which otherwise occurred every 5 sec. Once stable, efficient avoidance developed, each animal was food-deprived to 80% of his free-feeding weight. Sessions continued until the behavior again stabilized, after which the animal was returned to a free-feeding schedule. Eight such weight changes showed initial increases in response rate and decreases in shocks taken, irrespective of body weight (perhaps extended acquisition). In later sessions, avoidance efficiency was clearly positively correlated with body weight. Thus, deprivation had a deleterious effect on established avoidance, producing reduced response rate and increased shock rate.