THE EFFECTS OF CONCURRENT RESPONDING AND REINFORCEMENT ON BEHAVIORAL OUTPUT

Four birds key pecked on concurrent variable‐interval one‐minute variable‐interval four‐minute schedules with a two‐second changeover delay. Response rates to the variable‐interval one‐minute key were then reduced by signaling its reinforcer availability and later by providing its reinforcers independently of responding. Each manipulation increased response rates to the variable‐interval four‐minute key even though relative reinforcement rates were unchanged. In a final phase, eliminating the variable‐interval one‐minute key and its schedule produced the highest rates of all to the variable‐interval four‐minute key. These results show that both reinforcement and response rates to one schedule influence response rates to another schedule. These results join those of Guilkey, Shull, & Brownstein (1975) in failing to replicate Catania (1963). Moreover, they violate the predictions of the equation for simple action (de Villiers & Herrnstein, 1976). In terms of a median‐rate measure (reciprocal of the median interresponse time), rates to the variable‐interval four‐minute key were high when responding was not reduced to the variable‐interval one‐minute key and were low when it was reduced. This rate difference suggests a process difference between concurrent‐schedule procedures that maintain high concurrent response rates versus those that do not. This process difference jeopardizes attempts to integrate single‐ and concurrent‐operant performances within a single formulation.