ABSTRACT
The aim of this chapter is to show how sequential response choice may be used to examine the role of the central catecholamines, in particular, dopamine, in mediating the effects of reinforcers such as food. The law of effect states that responses followed by satisfaction to the responder will be repeated if the same circumstances arise again. Under a constant schedule of reinforcement of a particular response, the probability of occurrence (often expressed as rate) of that response will tend to increase and that of other, competing responses will fall. In simple terms, if an animal wins using a particular response, it should stay with that response. Such a rule is fundamental to the principle of reinforcement. In the second section of this paper, the involvement of dopamine in the operation of this rule is discussed, but before describing the effects of drugs or lesions on “win-stay,” it is necessary to show how it is possible to isolate this behavior from other influences on responding, and how it may then be used as an index of the effectiveness of reinforcers.
