Behavioral contrast : distribution of responses and time in a two-component multiple schedule of reinforcement

The concurrent properties of component performances on multiple variable-interval schedules of reinforcement were studied in six pigeons under conditions where pecks in each component of a two-component multiple schedule were reinforced according to concurrent schedules. The rationale for studying component performances within the context of a "multiple schedule of concurrent schedules" was based upon the assumption that within each component of a multiple schedule a certain proportion of the animal's time will be governed by the exteroceptive component stimulus of the multiple schedule while the remainder will be distributed among other concurrent response alternatives in direct proportion to their relative reinforcement value. Based upon this assumption, the present study sought to evaluate the hypothesis that behavioral contrast on multiple schedules results, at least in part, from a stimulus-specific shift in the reinforcement value associated with the unchanged component stimulus relative to the reinforcement value associated with stimuli occasioning other concurrent response alternatives