Concurrent schedules: Quantifying the aversiveness of noise

Area of Science:

• Animal behavior
• Operant conditioning
• Behavioral economics

Background:

• Aversive stimuli influence decision-making in animals.
• Understanding stimulus control is crucial in operant conditioning research.
• The generalized matching law models choice behavior under reinforcement.

Purpose of the Study:

• To investigate behavioral bias in hens exposed to an aversive auditory stimulus.
• To quantify this bias using a modified generalized matching law.
• To examine the impact of stimulus aversiveness on choice behavior and reinforcement schedules.

Main Methods:

• Four hens were exposed to independent multiple concurrent variable-interval schedules.
• An aversive auditory stimulus (100dBA poultry shed noise) was overlaid.
• The stimulus was activated by key pecks, with key roles systematically varied.

Main Results:

• A consistent behavioral bias away from the aversive stimulus was observed.
• This bias was independent of the specific variable-interval schedules in effect.
• Behavior during changeover delays was insensitive to the aversive stimulus and reinforcement rate changes.

Conclusions:

• A modified generalized matching law can quantify behavioral bias from aversive stimuli.
• Overall response measures may be less indicative of preference or aversiveness than behavior during specific delays.
• Behavioral bias provides a reliable indicator of stimulus aversiveness in operant conditioning paradigms.