Determinants of pigeons' choices in token-based self-control procedures

Area of Science:

• Behavioral Psychology
• Animal Cognition

Background:

• Self-control is the ability to forgo immediate smaller rewards for larger delayed rewards.
• Token-based procedures offer a way to study self-control by separating reinforcement delivery.

Purpose of the Study:

• To investigate how exchange delays and food delays affect choice behavior in a token-based self-control task.
• To determine the relative influence of reinforcer immediacy versus amount on pigeons' choices.

Main Methods:

• Four pigeons were trained on a token-based self-control procedure.
• Tokens were exchanged for food access, with varying delays to the exchange stimulus and food delivery.
• Exchange and food delays were manipulated independently and concurrently.

Main Results:

• A strong preference for smaller, immediate reinforcers emerged when both exchange and food delays were shorter for them.
• A strong preference for larger reinforcers emerged when delays were equal for both options.
• Manipulating exchange and food delays separately influenced preference, but less extremely than when both favored one option.

Conclusions:

• Reinforcer immediacy is a key factor when exchange and food delays are unequal.
• Reinforcer amount is more influential when exchange and food delays are equal.
• The exchange stimulus may function as a conditioned reinforcer, supporting self-control.