Schedule induced behavior: a review of its generality, determinants and pharmacological data.

Adjunctive or schedule induced behavior can be defined as an increase in the frequency of occurrence of an unreinforced behavior in the presence of conditions requiring an intermittent reinforced response, compared with the frequency of that behavior when no intermittent response is required. Although recognition has been given to the occurrence of other schedule induced behaviors it has most frequently been studied as schedule induced polydipsia in a rat on a food delivery schedule. In the present paper recent work on other schedule induced behaviors is reviewed including behaviors occurring in conjunction with nonconsumatory schedule parameters. These range from wheel running in the rat to game playing and maze solving in humans. This paper is also concerned with the review of pharmacological variables including the effects of peripheral and central administration. It is concluded that there may be either quantitative or qualitative differences in drug effects when schedule induced drinking is compared with deprivation induced drinking. A general activation theory [61] that adjunctive behaviors is the result of an increase in the excitability of motor pathways which lead through the lateral hypothalamus can account for the data presented in this and earlier reviews but is too broad in its conception to make specific predictions about the relationships between schedule induced and schedule controlled behavior.