5.04 - Ratio (response-based) Schedules

Continuous Reinforcement (CRF)
  • Definition: Continuous reinforcement occurs when every response is reinforced.
    • Example: Opening a closed door results in entering the room every time.
    • Example: Saying hello to a friend who always responds back.
Effects of Continuous Reinforcement
  • Main Effect: Responses are consistently rewarded, leading to skill in performing the specific behavior needed to obtain reinforcement.
  • Side Effect: Reduces variation in response; actions become stereotyped and automated.
    • Example: Habitual way of opening a specific door without conscious thought.
Intermittent Reinforcement
  • Definition: Reinforcement occurs sporadically rather than consistently.
  • Importance: Introduces complexity with various schedules that produce side effects on behavior.
Response-Based Schedules of Reinforcement
  • Schedules requiring multiple responses for reinforcement.
Fixed Ratio Schedule (FR)
  • Definition: Reinforcement is delivered after a fixed number of responses.
    • Example: SR5 means five responses are needed to receive reinforcement (e.g., food pellet for a rat after 5 lever presses).
  • Main Effect: The exact number of responses required, equivalent to the fixed ratio specified.
  • Side Effects:
    • Increased response rate as the ratio increases (e.g., FR15 vs. FR5).
    • Response Pattern: Characterized by a "break and run" response pattern where a quick response rate is followed by a pause after reinforcement delivery.
Cumulative Record of Fixed Ratio Schedule
  • Visual Representation:
    • Steeper slope indicates a higher rate of responding before the reinforcer is obtained.
    • Notable pauses after reinforcement; long pause for higher ratios (e.g., FR15 compared to FR5).
Real-World Application of Fixed Ratio
  • Piece Rate: An example where workers are paid per item produced (e.g., $1 for every 20 dresses made).
    • Exhibits "break and run" pattern similar to laboratory settings.
    • Ethical considerations: Workers can be pushed to complete high ratios quickly for minimal pay.
Variable Ratio Schedule (VR)
  • Definition: Reinforcement is given after a variable, unpredictable number of responses.
    • Example: A VR30 means on average 30 responses are required for reinforcement; actual responses can vary widely (1 to 60).
  • Main Effect: Obtaining reinforcement requires a mean of the specified responses.
  • Side Effect: High and consistent response rate due to unpredictability of reinforcement.
    • Example: Fishing casts; sometimes a fish is caught after one cast, other times after numerous tries.
Variable Ratio in Real Life
  • Gambling: A clear example of VR scheduling; players never know when they will win but continually play.
  • Social Dynamics: Playing hard to get in dating settings can also create a VR schedule, leading to increased interest and perseverance.
Random Ratio Schedule
  • Definition: Similar to variable ratio but with constant probability of reinforcement.
    • Each response maintains the same probability in context (i.e., coin flip analogy).
Comparison of Variable Ratio and Random Ratio
  • Resulting Behavior: Both lead to high rates of responding, but are conceptually distinct in terms of predictability and control mechanisms.
  • Visual Representation of VR:
    • Cumulative record shows a consistent high rate of responding with no pauses between reinforcements, contrasting the fixed ratio’s break and run pattern.