Skinner, Pavlov & Animal Learning

• This lecture covers the work of Skinner and Pavlov in the context of animal learning and cognition.

Historical Figures

• Charles Darwin (1809-1882).
• Edward Thorndike (1874-1949).
• John B. Watson (1878-1958).
• Burrhus Frederick (B.F.) Skinner (1904-1990).
• Ivan P. Pavlov (1849-1936).
• According to Skinner, understanding human behavior is key to solving the world's major problems.

Instrumental Conditioning (Operant)

• Involves a stimulus, response, and outcome (reinforcer).

Thorndike's Law of Effect

• A response leading to a satisfying outcome is strengthened.
• The outcome only strengthens or weakens the connection between the stimulus and response.
• The outcome is not represented in animals when making the instrumental response.

Colwill and Rescorla (1985)

• Conduct experiments to determine if animals only learn about a response.
• In Stage 1, rats learned that a lever press results in food, and a chain pull results in sucrose.
• In Stage 2, food became associated with illness and sucrose with nothing.
• In the test stage, both the lever and chain are available.
• The results suggest that animals learn more than just a response.

Key Concepts in Instrumental Conditioning

• Operant or instrumental conditioning.
• Response shaping.
• Schedules of reinforcement.

Schedules of Reinforcement

• Fixed Ratio (FR): Reinforcement after a fixed number of responses.
• Fixed Interval (FI): Reinforcement after a fixed amount of time has passed since the last reinforcement.
• A cumulative record for a Fixed Interval schedule shows responses increasing as the interval approaches expiration.
• Variable Ratio (VR): Reinforcement after a variable number of responses.
• Variable Interval (VI): Reinforcement after a variable amount of time has passed since the last reinforcement.
• Examples include FI (studying for exams), FR ('piece work' in factories), VI (Instagram), and VR (gambling).

Pavlovian or Classical Conditioning

• CS = conditioned stimulus (e.g., light)
• US = unconditioned stimulus (e.g., food)
• UR = unconditioned response (e.g., salivation)
• CR = conditioned response (e.g., salivation)

Conditioning Phases

• Before conditioning, a bell produces no response, while food elicits salivation.
• During conditioning, the bell is paired with food, eventually leading to the bell alone eliciting salivation.

Acquisition, Extinction, and Spontaneous Recovery in Classical Conditioning

• Acquisition: Learning the association between CS and US through repeated pairings.
• Extinction: Gradual decrease in the CR when the CS is repeatedly presented without the US.
• Spontaneous Recovery: Reappearance of the CR after a period of rest following extinction.

Stimulus Generalization

• Tendency to respond to stimuli similar to the CS.
• Can be represented graphically as a generalization gradient, showing how the strength of the response changes with the similarity to the original stimulus.
• Generalization decrement refers to the decrease in response as the stimulus becomes less similar to the original conditioned stimulus.

Rachman, S. J. (1966)

• Psychological Record 16, 293-296.
• Leather Boot (CS) paired with Picture (US).
• Initially, the Leather Boot (CS) elicits no response, while the Picture (US) elicits an unconditioned response.
• After conditioning, the Leather Boot (CS) elicits a conditioned response.

Stimulus Generalization Example in Behavior

• Graph demonstrates stimulus generalization with different types of footwear. The strongest response is to a knee-high boot, with decreasing responses to ankle boots, slippers, high heels, and bare feet.

Lecture on Skinner and Pavlov's work. Covers instrumental conditioning, Thorndike's Law of Effect and the work of Colwill and Rescorla. Examines animal learning and cognition.