Devaluation of a conditioned reinforcer requires its reexposure

Area of Science:

• Behavioral neuroscience
• Learning and memory
• Conditioned reinforcement

Background:

• Operant behavior change requires contact with outcomes during relevant motivational states (incentive learning).
• This principle is established for primary reinforcers but not for conditioned reinforcers.
• Conditioned reinforcers (e.g., audiovisual stimuli) previously associated with primary outcomes (food) are used in learning.

Purpose of the Study:

• To investigate whether incentive learning applies to conditioned reinforcers.
• To determine if affective value of conditioned stimuli is established upon initial contact.

Main Methods:

• Rats' lever-pressing behavior was reinforced with an audiovisual stimulus previously paired with food.
• Critical groups experienced a single pairing of the audiovisual stimulus with an electric shock.
• Some animals were re-exposed to the audiovisual stimulus post-aversive training; lever-pressing without outcome was tested.

Main Results:

• Animals re-exposed to the audiovisual stimulus after aversive conditioning showed reduced lever-pressing.
• Non-re-exposed animals did not differ from controls that received no aversive conditioning.
• Results indicate a change in behavior towards the conditioned reinforcer, not the primary reinforcer's value.

Conclusions:

• Affective value of conditioned stimuli is established upon initial contact, similar to unconditioned stimuli.
• Incentive learning principles extend to conditioned reinforcers.
• This study provides the first evidence for conditioned reinforcer affective value acquisition through contact.