Classical Conditioning
- Identify the US, UR, CS, and CR in examples of classical conditioning
- Explain acquisition, extinction, spontaneous recovery, and generalization
- Connect Pavlov, Watson, and biological constraints on learning
Pavlov’s discovery
Ivan Pavlov discovered classical conditioning — learning to associate two stimuli — while studying dogs’ salivation. Food (the unconditioned stimulus, US) naturally triggers salivation (the unconditioned response, UR), no learning required. When a neutral tone is repeatedly paired with the food, it becomes a conditioned stimulus (CS) that alone triggers salivation, now a conditioned response (CR). The key: a neutral stimulus, paired with something that already produces a response, comes to produce that response on its own. This is passive, automatic, reflexive learning.
The processes of conditioning
Conditioning unfolds in stages. Acquisition is the initial learning of the CS–US association, strongest when the CS comes just before the US. Extinction is the weakening of the CR when the CS is presented repeatedly without the US. Spontaneous recovery is the reappearance of a weakened CR after a rest — showing extinction suppresses rather than erases learning. Generalization is responding to stimuli similar to the CS (a child bitten by one dog fears all dogs); discrimination is learning to respond only to the specific CS and not to similar ones.
Watson, Little Albert, and biological limits
John B. Watson showed conditioning applies to humans and emotions in the Little Albert study: he paired a white rat (neutral) with a loud, frightening noise (US) until the infant feared the rat (CR) and generalized the fear to other furry objects. But learning is not unlimited: biological preparedness means some associations form far more easily than others. Garcia and Koelling’s taste-aversion research showed animals readily link nausea to taste (even hours later) but not to lights or sounds — a survival-tuned constraint on what conditioning can teach.
A child gets sick after eating a specific brand of chicken soup and afterward feels nauseated at the mere smell of it, though nothing was wrong with the soup. Identify the US, UR, CS, and CR, and name the phenomenon.
- 1.Find the natural reflex: the illness (from a stomach bug) automatically caused nausea, so the illness is the unconditioned stimulus (US) and the nausea it caused is the unconditioned response (UR).
- 2.Find the neutral stimulus that got paired: the smell/taste of the soup was neutral but was present when the child got sick.
- 3.Identify the learned trigger: after the pairing, the soup’s smell alone now triggers nausea, making the soup smell the conditioned stimulus (CS).
- 4.Identify the learned response: the nausea now produced by the soup smell is the conditioned response (CR); this rapid, one-trial learning is a taste aversion, an example of biological preparedness.
A dog learns to salivate to a bell paired with food. Later the bell is rung many times with no food, and salivation stops. After a two-week break, the bell is rung again and the dog salivates. This reappearance is called:
To label the four terms, start with the automatic reflex: the Unconditioned pair happens Unlearned. Whatever the organism had to learn to respond to is the Conditioned stimulus, and its learned reaction is the Conditioned response. Find the reflex first, then the neutral stimulus that borrowed it.
In Watson’s Little Albert study, the infant was conditioned to fear a white rat and then also showed fear toward a rabbit, a dog, and a fur coat. The spreading of fear to similar objects illustrates:
On classical-conditioning FRQs, always identify the response type: classical conditioning produces an automatic, reflexive response (salivation, fear, nausea) to a stimulus. If the behavior is voluntary and shaped by consequences, it is operant, not classical.
Answer the 2 checkpoints as you read.
Sign in to save your progress