The effects of signalled reinforcement in multiple schedules of reinforcement

In a two-component multiple variable interval schedule of reinforcement, responding in a blue, nonsignalled component was found to be a decreasing, negatively accelerated function of the rate of reinforcement in a red, signalled component. It was clearly demonstrated that the interaction between responding in one component of a multiple schedule and reinforcement rate in a second, regularly alternated component will occur in the absence of large variations in response rate in the component in which reinforcement rate is varied. Neither the Catania function for concurrent schedules nor the Lander and Irwin function for multiple schedules accurately predicted responding in the present situation, although a function of the same general form appeared appropriate. When equal VI schedules were in effect in both components, the effect of signalling reinforcement in one component was a decrease in responding in the signalled component and a corresponding increase in responding in the unchanged component. Upon removal of the signal, responding in the previously signalled component recovered (increased), while responding in the unchanged component showed a gradual decline. Both positive and negative behavioral contrast were observed in the absence of changes in reinforcement rate