Conditioned reinforcement and discrimination in second-order schedules

Area of Science:

• Behavioral psychology
• Animal behavior studies

Background:

• Second-order schedules involve stimuli that predict primary reinforcement.
• Conditioned reinforcers gain value by association with primary reinforcers.

Purpose of the Study:

• To investigate the discriminative and conditioned reinforcing effects of brief stimuli in pigeons.
• To examine how these effects are modulated by schedule parameters and other reinforcers.

Main Methods:

• Pigeons were exposed to second-order schedules with variable-interval or fixed-interval reinforcement.
• Brief stimuli were presented, with a terminal response required for food.
• Discrimination between stimuli and response rates were measured.

Main Results:

• Response rates were higher in paired brief-stimulus schedules compared to unpaired or tandem schedules.
• Rate enhancement persisted when stimuli created discrimination between early and late components.
• Rate enhancement diminished with longer initial links or when the stimulus-reinforcement contingency was removed.

Conclusions:

• The discriminative and conditioned reinforcing effects of food-paired stimuli can be manipulated.
• Conditioned reinforcement is influenced by the broader reinforcement context.