Performance and feedback function on variable differential reinforcement of low rates: Tempus urgit vel abundat?

Area of Science:

• Behavioral neuroscience
• Animal behavior studies
• Operant conditioning

Background:

• The variable-differential-reinforcement-of-low-rates (VDRL) schedule's impact on behavior is understudied.
• Temporal uncertainty is a key feature of VDRL schedules, influencing response patterns.

Purpose of the Study:

• To investigate rat behavior under a 10-s VDRL schedule.
• To analyze the temporal organization of responding and identify behavioral structures.

Main Methods:

• Utilized survival analysis of interresponse times to examine rat performance.
• Exposed ten rats to a 10-s VDRL schedule after baseline training.
• Evaluated the reinforcement feedback function (RFF) using a Hill-type function and computational modeling.

Main Results:

• Identified a consistent three-stage behavioral structure: within-bout responding, an intermediate waiting phase, and bout initiation.
• Observed sustained, imperfect response inhibition during the intermediate phase, indicating adaptive waiting.
• Demonstrated that longer pauses could enhance reinforcement rates, even with reduced overall responding, and showed close agreement between simulated and observed data.

Conclusions:

• VDRL schedules produce temporally structured behavior driven by a balance between responding and waiting.
• The findings support the use of computational models for estimating reinforcement feedback functions.
• Behavior under VDRL suggests adaptive strategies for managing temporal uncertainty.