Overview
This lecture explains Pavlov's theory of classical conditioning, outlining key terms and describing the process through experiments and examples.
Key Concepts in Classical Conditioning
- A stimulus is anything in the environment presented to a person or animal.
- A response is the reaction to a stimulus.
- An unconditioned stimulus (US) naturally produces a response without learning, e.g., food causing salivation in dogs.
- An unconditioned response (UR) is the natural reaction to an unconditioned stimulus, e.g., salivating to food.
- A neutral stimulus (NS) does not naturally produce a response, e.g., a bell before conditioning.
- When a neutral stimulus is paired repeatedly with an unconditioned stimulus, it becomes a conditioned stimulus (CS).
- A conditioned response (CR) is the learned response to the conditioned stimulus, e.g., salivating to a bell after conditioning.
Pavlov's Experiment
- Pavlov presented meat (US) to dogs, causing them to salivate (UR).
- A bell (NS) rung alone did not cause salivation initially.
- Pavlov paired the bell (NS) with meat (US); over time, the bell alone (now CS) caused dogs to salivate (CR).
Important Processes
- Acquisition is the phase when the conditioned response is learned by repeatedly pairing CS and US.
- Extinction occurs when the CS (e.g., bell) is presented repeatedly without the US (e.g., meat), causing the CR (salivation) to fade.
- Spontaneous recovery is when the CR reappears after extinction, following a rest period.
Example: Cheeseburger and Sickness
- Eating bacteria-contaminated cheeseburgers (US) causes sickness (UR).
- Cheeseburger alone (initially NS) becomes associated with getting sick.
- Eventually, seeing or eating a cheeseburger (now CS) causes sickness (CR), even if there's no bacteria present.
Key Terms & Definitions
- Stimulus — any item or event in the environment that elicits a response.
- Response — a behavior or reaction to a stimulus.
- Unconditioned Stimulus (US) — naturally triggers a response without prior learning.
- Unconditioned Response (UR) — an automatic, natural reaction to the unconditioned stimulus.
- Neutral Stimulus (NS) — does not trigger any response before conditioning.
- Conditioned Stimulus (CS) — a previously neutral stimulus that now elicits a response after association with the US.
- Conditioned Response (CR) — a learned response to the conditioned stimulus.
- Acquisition — the learning stage where the CS and US are paired to produce the CR.
- Extinction — the diminishing of a CR when the CS is no longer paired with the US.
- Spontaneous Recovery — the reappearance of a CR after it has been extinguished.
Action Items / Next Steps
- Review definitions and examples for each term related to classical conditioning.
- Practice identifying US, UR, NS, CS, and CR in different scenarios.
- Prepare for questions about acquisition, extinction, and spontaneous recovery for the next test.