Choice in a variable environment: every reinforcer counts.

Area of Science:

• Behavioral science
• Animal behavior

Background:

• Pigeons were trained on concurrent-schedule tasks with varying reinforcer ratios.
• Components occurred irregularly, lacking distinct signals for different ratios.

Purpose of the Study:

• To investigate how pigeons adjust their response allocation under changing concurrent-schedule reinforcer ratios.
• To examine the influence of overall reinforcer rate and component reinforcer number on learning speed and sensitivity.

Main Methods:

• Six pigeons were exposed to conditions with different reinforcer ratios and overall rates.
• Data were collected over 35 sessions, analyzing response allocation and sensitivity to ratio changes.
• The effect of carryover from prior components was assessed.

Main Results:

• Response allocation adjusted quickly within components, with sensitivity leveling off around eight reinforcers.
• Higher overall reinforcer rates accelerated adjustment and increased sensitivity.
• Confirming reinforcers had diminishing effects, while disconfirming reinforcers had significant impacts.

Conclusions:

• Pigeon's choice behavior demonstrates rapid adaptation to changing reinforcer schedules.
• Overall reinforcer rate significantly modulates the speed and extent of behavioral adjustment.
• Carryover effects from previous components play a role in subsequent choice behavior.