Within-session changes in key and lever pressing for water during several multiple variable-interval schedules.

Area of Science:

• Behavioral science
• Animal behavior research
• Operant conditioning

Background:

• Understanding within-session patterns of behavior is crucial for behavioral science.
• Previous research has explored reinforcement schedules and their effects on response rates.

Purpose of the Study:

• To investigate how different rates of water reinforcement affect response patterns in rats over time.
• To compare within-session changes in lever pressing and key pressing for water versus food reinforcers.

Main Methods:

• Rats were trained to press keys or levers for water under multiple variable-interval schedules.
• Reinforcement rates varied from 15 to 240 reinforcers per hour.
• Within-session response patterns were analyzed for lever and key pressing.

Main Results:

• Responding typically increased and then decreased within experimental sessions.
• Within-session changes were smaller, later, and more symmetrical at lower reinforcement rates.
• Quantitative differences emerged at high reinforcement rates for different response types and reinforcers.

Conclusions:

• Similar underlying factors influence within-session response changes for different responses and reinforcers.
• Reinforcer type and response choice modify these changes, especially at high reinforcement rates.
• Applying Herrnstein's equation to averaged rates requires careful consideration of these within-session dynamics.