BEHAVIORAL-CONTRAST USING DIFFERENT REINFORCERS - EFFECT OF BASE-LINERATE OF REINFORCEMENT

The present study determined whether behavioral contrast would occur w hen different reinforcers were delivered in the different components a nd whether its size would vary at different baseline rates of reinforc ement. Pigeons pecked keys on a multiple variable-interval schedule. M ixed grain was the reinforcer in one component and wheat was the reinf orcer in the other component. In contrast conditions, the rate of whea t reinforcement was increased or decreased, from the baseline delivery rate, by a factor of four. Contrast was studied at four different bas eline rates of reinforcement. Contrast was usually observed and its si ze almost always varied directly with the programmed baseline rate of reinforcement. The present results indicate that changes in the condit ion of reinforcement of a different reinforcer can produce contrast. T hey also broaden the potential implications of behavioral contrast. (C ) 1998 Elsevier Science B.V. All rights reserved.