Reinforcement Schedules and Learning Behavior

Reinforcement Schedules

• Definition of Reinforcement Schedules

  • Reinforcement schedules refer to the systems that dictate how often and under what conditions a reinforcement is provided following a behavior.

  • It is counterintuitive yet crucial to understand that reinforcement does not need to occur after every instance of a behavior to maintain that behavior.

• Importance of Response Contingency

  • While it is important for reinforcement to be contingent upon a response, and to be delivered immediately after the behavior occurs, it is not necessary for every single occurrence of the behavior to be reinforced.

• Partial Reinforcement

  • Definition: Partial reinforcement occurs when a behavior is reinforced less than every time it is performed.

  • Example: When training a rat to press a bar, it is often reinforced every time at the beginning stages, but gradually, the reinforcement is thinned out.

  • Benefits of Partial Reinforcement:

  • Increases the frequency and strength of the behavior.

  • Creates resistance to extinction (the ability for a learned behavior to persist even when reinforcement is withheld).

• Example of Resistance to Extinction:

  • For a rat reinforced every time it presses the bar, it may take about 75 presses before it stops.

  • If reinforced only once every fifty presses, the rat might continue bar pressing for tens of thousands of times before stopping.

Types of Partial Reinforcement Schedules

• Fixed Ratio (FR) Schedules

  • Definition: The reinforcement is provided after a fixed number of responses.

  • Example: An FR of 2 means the rat must press the bar twice to receive reinforcement. An FR of 50 means the rat must press 50 times.

  • Gradually increasing the number of responses needed for reinforcement is essential to avoid extinction.

  • Graphical Representation:

  • Cumulative record indicates how many times the rat presses the bar; steep slopes indicate quick responding after reinforcement.

  • Post-Reinforcement Pause:

  • Following reinforcement, a pause occurs; the length of this pause increases with higher ratio schedules.

  • Example: In piecework jobs, like stuffing envelopes.

• Variable Ratio (VR) Schedules

  • Definition: Reinforcement is provided after a variable number of responses, introducing an element of unpredictability.

  • Example: A VR schedule averages to reinforcement every 50 presses, but the actual number may vary (such as 20, 65, 35 presses).

  • Real-World Application:

  • Slot machines operate on a variable ratio schedule, encouraging continued play due to the uncertainty of when the reward will occur.

• Fixed Interval (FI) Schedules

  • Definition: Reinforcement is available for the first response following a fixed time period.

  • Example: An FI of 2 minutes means reinforcement is given after the first bar press following the 2-minute wait period.

  • Behavioral Pattern:

  • Creates a scalloped curve where response rates increase as the time for reinforcement approaches.

  • Example: Studying correlates with fixed intervals resembling cramming before exams.

• Variable Interval (VI) Schedules

  • Definition: The time between reinforcement varies unpredictably, meaning the responder cannot predict when it will happen.

  • Example: Pop quizzes or randomly scheduled tests require constant studying due to uncertainty.

  • Behavioral Pattern:

  • Leads to slow, steady responding due to the uncertainty of reinforcement timing.

Discriminative Learning

• Definition: Discriminative learning involves the ability to respond differently in the presence of different stimuli.

• Discriminative Stimuli:

  • Refers to stimuli that signal when a response will be reinforced, influencing the likelihood of the response occurring.

  • Example: A child says "dog" in front of a dog but not in front of a cat because the presence of the dog provides reinforcement for the behavior whereas the cat does not.

• Generalization:

  • Occurs when similar stimuli evoke a similar response.

  • In the example, a child might call different breeds of dogs "dog" after learning the word through reinforcement.

• Stimulus Control:

  • The concept of how stimulus conditions influence the likelihood of a behavior's occurrence, highlighting the roles of both discrimination and generalization.

Programmed Instruction

• Definition: A teaching method developed by B.F. Skinner that applies principles of operant conditioning to education.

• Purpose: To optimize learning and ensure mastery of material through careful structuring of information into smaller, manageable units.

• Process:

  • Learners are required to practice until they can perform a task without error before advancing to new material.

  • Promotes mastery over performance and avoids situations where students proceed without understanding (e.g., progressing to Algebra II without mastering Algebra I).

Observational Learning

• Definition: Learning that occurs through observing the behavior of others and imitating their actions.

• Bandura's Study:

  • Demonstrated that children would mimic adult behavior observed in interacting with a punching bag (Bobo).

  • Children either displayed positive (affiliative) or negative (aggressive) behaviors towards Bobo based on adults' actions.

Cognitive Mapping

• Definition: The mental representation of spatial relationships learned without direct reinforcement, as argued by researcher Edward Tolman.

• Tolman's Experiment:

  • Rats navigated a maze without reinforcement, yet when reinforcement was introduced, they quickly reached the goal box, proving they had learned the route through cognitive mapping.

Behavior Modification

• Definition: The application of behavioral principles from classical and operant conditioning techniques to create therapeutic behavior changes.

• Application:

  • Effective in treating diverse issues, including depression, by reinforcing behaviors incompatible with depression, such as social engagement and activity.

  • Various techniques include:

  • Aversion Therapy: Uses unpleasant stimuli to deter negative behaviors, such as using Antabuse for alcohol dependency.

    • Combines Antabuse with alcohol consumption to induce vomiting, minimizing the desire for alcohol.

  • Systematic Desensitization: Treatment for phobias that gradually exposes individuals to feared stimuli while maintaining a state of relaxation.

  • Operant Therapies: Combine various methods of reinforcement, extinction, and punishment tailored to individual needs, especially in populations with specific psychiatric conditions.

• Strategies for Implementation:

  • Behavioral modification approaches are designed to change specific behaviors by rewarding or punishing them and are frequently applied in the context of Autism and other behavioral issues, creating structured environments to increase success.

Conclusion

• Understanding the nuances of reinforcement schedules and behavior modification techniques is essential for effective learning and therapeutic interventions.

• The next topic will focus on memory, presenting further insights and methodologies in cognitive psychology.