6.12 Understanding Variable Schedules of Reinforcement

Overview of Reinforcement Schedules

Introduction to Variable Schedules

  • Transition from fixed schedules to variable schedules

  • Focus on Variable Interval (VI) and Variable Ratio (VR) schedules.

Variable Interval Schedule (VI)

  • Definition: Reinforcement is based on the passage of time, but the amount of time is unpredictable.

  • Example: A rat in an operant chamber waits a variable amount of time to receive food.

    • Specific Scenario:

    • Variable interval of 100 seconds means:

      • One trial could require a wait of 110 seconds before reinforcement (lever press leads to food).

      • Another trial may need only 90 seconds.

  • Outcome: Average wait time results in a consistent level of responding.

Real-world Applications of Variable Interval Schedules

  • Meteor Showers:

    • Stargazing participants experience an unpredictable wait for shooting stars.

    • Average occurrence could be a shooting star every five minutes.

  • Workplace Context:

    • Supervisors (e.g., bosses) utilizing variable interval schedules to encourage consistent work.

    • Effectiveness vs. Fixed Interval:

    • Fixed schedules would cause workers to only work in anticipation of the boss’s presence (leading to scalloped responding pattern).

    • Use of variable schedules compels consistent productivity from employees.

Variable Ratio Schedule (VR)

  • Definition: Reinforcement based on an unpredictable number of behaviors (responses).

  • Example with the Rat:

    • Rat receiving food after an average of 10 lever presses:

    • One trial may require 12 presses, the next may only need 8 presses.

  • Outcome: Average across trials will suggest 10 presses yield food.

  • Behavioral Impact: Results in a high rate of responding in a short time frame.

Real-world Applications of Variable Ratio Schedules

  • Gambling Context:

    • Casinos and slot machines employ VR schedules to motivate behavior, sometimes leading to addiction.

    • The unpredictable rewards in gambling create a sense of anticipation that drives players to continue.

  • Motivation Effect:

    • The sense of control over outcomes increases motivation to perform the behavior (e.g., pressing the lever).

    • Unpredictable nature leads players to keep hoping for the next reward, making the experience addictive.

Comparative Analysis: Ratio Schedules vs. Interval Schedules

  • General Observations:

    • Ratio schedules, especially variable ones, lead to higher rates of responding compared to interval schedules.

    • This is due to the direct correlation to our actual responses, providing a sense of control and agency.

Partial Reinforcement Effect

  • Definition: Takes longer for individuals to experience extinction under partial reinforcement than under continuous reinforcement.

  • Analogies:

    • Continuous reinforcement example using a slot machine:

    • Winning every time creates a strong association; not winning easily recognizable results in quick abandonment of the machine.

    • In contrast, with partial reinforcement, inconsistent wins create a lower expectation of consistent feedback, allowing continued play despite losses.

Implications for Gambling Addiction

  • Understanding of Mechanisms:

    • Casinos utilize learning principles to enhance player retention and prolong engagement.

    • Use of both classical and operant conditioning principles:

    • Positive reinforcement (wins) via conditioned stimuli (flashing lights, sounds) elicits excitement and motivates further play.

  • Downside:

    • Disguising losses as wins impacts player perception; for example, players may feel they won even when they lost overall.

    • Scenario: Betting on multiple lines in a slot machine leading to perceived wins, but still incurring losses overall (e.g., betting $15 but receiving only $10).

Conclusion

  • Variable schedules, both interval and ratio, have significant applications in real-world contexts, particularly in motivating behaviors.

  • Understanding these mechanisms can shed light on issues of addiction and the influence of external stimuli in promoting certain behaviors.