Human Concurrent Performances: Variation of Reinforcer Magnitude and Rate of Reinforcement

Abstract

Humans participated in experiments using concurrent variable-interval variable-interval schedules. Reinforcer magnitude or rate of reinforcement availability was varied. Relative rate of responding was insensitive to changes in relative reinforcer magnitude. When relative rate of reinforcement was altered, relative rate of responding increased in the component with the shorter average interreinforcement interval. Participants were also exposed to concurrent variable-interval extinction schedules to test for sensitivity to schedule parameters. All participants continued responding in the variable-interval component while responding in the extinction component diminished. The current study is one of a limited number of experiments that examine responding by humans in procedures designed to approximate those used in animal studies. The findings are consistent with those of some animal studies in which responding under concurrent variable-interval variable-interval schedules was examined. In particular, the data indicate that frequency of reinforcement affects response distribution in humans more than does magnitude of reinforcement. Thus frequent delivery of smaller reinforcers may be more effective in modifying human behavior than infrequent delivery of larger reinforcers.