Response rate, reinforcement frequency, and behavioral contrast.

Area of Science:

• Behavioral psychology
• Animal behavior studies
• Operant conditioning principles

Background:

• Pigeons were trained on a multiple schedule with alternating green and red key stimuli.
• A variable-interval (VI) 2-min schedule of reinforcement was initially applied during both stimuli.

Purpose of the Study:

• To investigate how differential reinforcement of low response rates (DRL) during one stimulus component affects responding.
• To examine potential contrast effects in the other stimulus component under these conditions.
• To determine if reinforcement frequency reductions, independent of response rate, can cause schedule interactions.

Main Methods:

• Pigeons were exposed to a multiple schedule with green and red key stimuli.
• Differential reinforcement of low rates (DRL) was implemented during the green stimulus, requiring interresponse times greater than 2 seconds.
• The variable-interval (VI) schedule during the red stimulus remained unchanged.
• Reinforcement frequency during the green stimulus was later reduced by changing to a VI 8-min schedule while maintaining low response rates via the DRL requirement.

Main Results:

• Response rates decreased during the green stimulus when DRL was introduced, without altering reinforcement frequency.
• No clear contrast effects were observed in the red stimulus during the DRL phase.
• When reinforcement frequency was reduced in the green stimulus (VI 8-min), response rates in the red stimulus increased, despite unchanged red stimulus conditions.

Conclusions:

• Reductions in reinforcement frequency can independently influence behavior in multiple schedules.
• These findings demonstrate that schedule interactions can occur even when response rates are not directly manipulated.
• The study highlights the complex interplay between reinforcement schedules and behavioral responding.