The mechanics of reinforcement

Mathematical principles of reinforcement were developed in order to (1) account for the interaction of target responding and other behavior; (2) provide a simple graphical representation; (3) deal with measurement artifacts; and (4) permit a coherent transition from a statics to a dynamics of behavior. Rats and pigeons were trained to make a target response while general activity was measured with a stabilimeter. The course of behavioral change was represented as a trajectory through a two-dimensional behavior space. The trajectories rotated toward or away from the target dimension as the coupling between the target response and the incentive was varied. Higher rates of reinforcement expanded the trajectories; satiation and extinction contracted them. Concavity in some trajectories provided data for a dynamic generalization of the model.