Behavioral Contrast as a Function of Component Duration and Baseline Rate of Reinforcement

Three experiments examined changes in size of multiple-schedule behavioral contrast with changes in an independent variable. Experiment 1 found that positive contrast generally increased with increases in component duration when pigeons pressed treadles. Experiments 2 and 3 found that positive and negative contrast generally increased with increases in the baseline rates of reinforcement when pigeons pecked keys. The experiments show that positive and negative contrast vary as similar functions of the same variables. Experiment 1 also suggests that these functions are different for different responses.