Control of Behavior by Stimuli Associated with Drug Injections

Abstract

In the life of an addict the actual taking of drugs is highly intermittent. Each drug injection is preceded by a set sequence of behavior involving obtaining money, purchasing the drug, and preparing to inject the drug. The environmental stimuli associated with this set sequence of behavior, such as locations, injection rituals, and the presence of friends, come to play a very important role in the maintenance of drugseeking behavior. Although the importance of this set sequence of behavior has been extensively discussed, notably by Wikler (e.g., 1965) and Vaillant (e.g., 1969), and is generally accepted, there is little direct experimental evidence that is relevant. Studies of the performance of experimental animals under complex schedules of drug injection analogous to those operating with human addicts might provide such evidence. The present paper describes briefly a way of exploring long and orderly sequences of behavior controlled by scheduled presentations of stimuli which are intermittently associated with drug injections.

This research was supported by U.S.P.H.S. Grants MH-07658, MH- 02094, MH-07084 and HE-14150. I am indebted to Dr. J. Alan Herd of the Department of Physiology, Harvard Medical School, who performed the surgery in these experiments, and to Drs. R. T. Kelleher W. H. Morse and P. B. Dews for helpful comments during preparation of this paper.