Changes in functional response units with briefly delayed reinforcement

Area of Science:

• Behavioral Psychology
• Animal Behavior
• Operant Conditioning

Background:

• Understanding how delays in reinforcement affect behavior is crucial for behavioral psychology.
• Pigeon key-peck responding is a standard model for studying operant conditioning principles.

Purpose of the Study:

• To investigate the impact of unsignaled delays in reinforcement on pigeon key-peck response structure.
• To determine if delays alter the functional unit of response.

Main Methods:

• Two experiments compared key-peck responding under variable-interval schedules with immediate versus unsignaled delays.
• Interresponse times and response frequencies were analyzed under different delay conditions (0.5-s and 5.0-s).

Main Results:

• A 0.5-s unsignaled delay decreased reinforced interresponse time duration and increased short interresponse times.
• A 5.0-s unsignaled delay increased reinforced interresponse time duration and decreased short interresponse times.
• These effects persisted even when the baseline schedule already favored short interresponse times.

Conclusions:

• Unsignaled delays can change the functional response unit from a single peck to a multiple-peck unit.
• Contingencies control response structure even without explicit structural requirements.