Operant Conditioning and Reinforcement

Operant Conditioning Overview

• Definition: Operant conditioning involves learning through associations between stimuli and voluntary responses.
• Key Components: Operant conditioning is characterized by two main concepts: contiguity (context) and contingency (predictions).

The Three-Term Contingency

• Discriminative Stimulus (Sd): Represents the context or situation in which a behavior occurs.
• Response (R): The voluntary action taken by an organism (unlike unconditioned responses).
• Consequence (S*): The outcome of the response, which can be either a reinforcer or a punisher.

Example of Three-Term Contingency

• In context (Sd) --> Response (R) --> Produces consequence (S*)

Thorndike's Law of Effect

• Two Parts:
  1. A response followed by a satisfying consequence will increase in frequency.
  2. A response followed by an unsatisfying consequence will decrease in frequency.
• Reinforcer: Satisfying consequence (increases behavior).
• Punisher: Unsatisfying consequence (decreases behavior).

Types of Reinforcers and Punishers

• Positive Reinforcer: Adds something desirable to increase behavior.
  • Example: Homework before dinner, add a prize.
• Negative Punisher: Takes away something desirable to reduce behavior.
  • Example: Homework not done, take away a privilege.
• Positive Punisher: Adds something undesirable to reduce behavior.
  • Example: Homework not done, impose a penalty.
• Negative Reinforcer: Takes away something undesirable to increase behavior.
  • Example: Homework done, removal of restrictions.

Behavior Modification Programs

• Reinforcer Hierarchies:
  • Includes primary reinforcers (biological — food, safety) and secondary reinforcers (learned, access to primary).
• Response Hierarchies:
  • Hull's Habit Families and Skinner's Functional Response Classes.
• Shaping: Method of successive approximations toward desired behavior, reinforced progressively.
  • Example Steps:
  1. Rat rears anywhere in Skinner box.
  2. Reinforce rearing in half of box.
  3. Reinforce rearing in quarter of box.
  4. Reinforce bar press with food or water.

Schedules of Reinforcement

• Types of Schedules: Ratio and Interval schedules that determine how reinforcement is delivered.
• Ratio Schedules:
  • Fixed Ratio: Constant responses lead to reinforcement; results in post-reinforcement pauses.
  • Variable Ratio: Reinforcement after an average number of responses; creates unpredictability (similar to gambling).
• Interval Schedules:
  • Fixed Interval: Know when the next reinforcer is due; can cause scalloped responding.
  • Variable Interval: Uncertain timing of reinforcement; no pauses.

Commonalities Between Classical and Operant Conditioning

1. Contiguity: Co-occurrence of stimuli (fundamental for all learning).
2. Contingency: Relationship where one event predicts another (both in Pavlovian and Operant conditioning).
3. Surprise: Learning occurs best with new or unexpected events.
4. Phases of Learning:
   • Conditioning: Initial learning phase.
   • Extinction: When the predictive relationship breaks down; the behavior is not reinforced anymore.
   • Spontaneous Recovery: The re-emergence of a previously extinguished behavior upon reintroduction of the context or stimulus.
   • Associative Networks: Neural connections formed through learning that strengthen predictions.

Discussion Topic

• Free Will in Operant Conditioning: Exploring the implications of behavior control and conditioning in relation to free will, discussed in class.