ABSTRACT
This chapter examines the peak shift, behavioral contrast, and the relative slopes of excitatory and inhibitory gradients, from the point of view of two simple assumptions. The first is that different activities may be under the control of different stimuli, which may or may not overlap in their effects. The second assumption is that activities tend to compete with each other for the available time. In a constant environment, the “strength” of a behavioral state can be identified with the frequency of behaviors associated with that state. If schedule-induced drinking is taken as a measure of the strength of the interim state, and the frequency of a terminal response such as lever pressing or key pecking measures the strength of the terminal state, then it appears that the relation between terminal and interim states is reciprocal. Such factors as rate of food delivery and food deprivation affect the level of interim and terminal activities similarly.
