Background activities, induction, and behavioral allocation in operant performance

In experiments on operant behavior, other activities, called “background” activities, compete with the operant activities. Herrnstein's ([Herrnstein, R. J., 1970]) formulation of the matching law included background reinforcers in the form of a parameter r O , but remained vague about the activities ( B O ) that produce r O . To gain more understanding, we analyzed data from three studies of performance with pairs of variable‐interval schedules that changed frequently in the relative rate at which they produced food: Baum and Davison ([Baum, W. M., 2014]), Belke and Heyman ([Belke, T. W., 1994]), and Soto, McDowell, and Dallery (2005). Results sometimes deviated from the matching law, suggesting variation in r O . When r O was calculated from the matching equation, two results emerged: (a) r O is directly proportional to B O , as in a ratio schedule; and (b) r O and B O depend on the food rate, which is to say that B O consists of activities induced by food, as a phylogenetically important event. Other activities unrelated to food ( B N ) correspond to Herrnstein's original conception of r O and may be included in the matching equation. A model based on Baum's (Baum, 2012) concepts of allocation , induction , and contingency explained the deviations from the matching law. In the model, operant activity B , B O , and B N competed unequally in the time allocation: B and B O both replaced B N , B O replaced lever pressing (Soto et al.), and key pecking replaced B O (Baum & Davison). Although the dependence of r O and B O on food rate changes Herrnstein's ([Herrnstein, R. J., 1970]) formulation, the model preserved the generalized matching law for operant activities by incorporating power‐function induction.