Learning and Behavior: Reinforcement, Punishment, and Conditioning

Schedules of Reinforcement: Ratio vs. Interval

• All behaviors are learned, but some are intentionally reinforced or repaired.

• Ratio Schedules: Based on performance or the number of behaviors completed.

  • Fixed Ratio: Reinforcement after a fixed number of behaviors (e.g., every $2^{nd}$ or $3^{rd}$ time). This schedule is predictable.

  • Variable Ratio: Reinforcement after an unpredictable, average number of behaviors (e.g., sometimes $2$, sometimes $4$, sometimes $5$). This schedule is random.

  • Coke Machine vs. Slot Machine Analogy:

  • Coke Machine (Fixed Ratio): Every time money is put in, a drink is expected. When the expectation is broken, the behavior stops quickly.

  • Slot Machine (Variable Ratio): Money is put in, but the reinforcement (winning) is unpredictable. This leads to a stronger, longer-lasting behavior.

  • Behavior Strength: Variable ratio schedules produce stronger and more persistent behaviors because the individual doesn't know when to expect the reinforcement, leading them to continue the behavior in hope of it.

  • Teaching New Behaviors: Start with a fixed ratio (e.g., one-to-one reinforcement) to establish the behavior quickly, then transition to a variable ratio to strengthen and maintain it. This prevents rapid extinction when reinforcement becomes less frequent.

  • Extinction Burst: An initial increase in the behavior when reinforcement stops (e.g., shaking a Coke machine that doesn't dispense a drink).

  • Extinction and Learning History: If a behavior has a long history of fixed-schedule reinforcement, its extinction can be surprising (e.g., a Coke machine eating money after hundreds of successful uses). Moving to a variable schedule quickly prevents this long history of fixed expectation.

• Interval Schedules: Based on time elapsed since the last reinforcement, not the number of behaviors.

  • Fixed Interval: Reinforcement becomes available after a fixed amount of time (e.g., every $3$ months). Behaviors tend to increase as the time for reinforcement approaches, creating a "scalloped" pattern of responding, with a pause after reinforcement and then a gradual increase in activity.

  • Variable Interval: Reinforcement becomes available after an unpredictable, average amount of time (e.g., sometimes $5$ minutes, sometimes $10$ minutes, sometimes $15$ minutes, averaging $10$ minutes). This schedule produces a slow, steady rate of response because the individual cannot predict when reinforcement will be available but knows it will eventually come.