Detecting a nonevent: Delayed presence-versus-absence discrimination in pigeons

Area of Science:

• Cognitive Psychology
• Animal Behavior
• Behavioral Neuroscience

Background:

• Investigating memory and decision-making in pigeons using a delayed discrimination paradigm.
• Examining how retention interval affects performance in presence-versus-absence tasks.

Purpose of the Study:

• To analyze pigeon performance in a delayed discrimination task with varying sample presence.
• To compare the predictive power of discrete-state models versus signal detection theory.

Main Methods:

• Pigeons were trained on a delayed presence-absence discrimination task.
• Performance was assessed across increasing retention intervals.
• Reinforcement schedules were manipulated in a second phase to test preference.

Main Results:

• Performance remained high on no-sample trials but declined significantly on sample trials as retention interval increased.
• Pigeons did not initially prefer richer reinforcement options but developed a strong preference in Phase 2 under probabilistic reinforcement.
• Observed data contradicted discrete-state model predictions but aligned with signal detection theory.

Conclusions:

• Signal detection theory provides a more robust framework for understanding pigeon performance in this discrimination task.
• The findings challenge discrete-state models and highlight the utility of signal detection theory for explaining memory-related behaviors.