What occurs during extinction in classical conditioning?

• A. The conditioned response remains unchanged over time
• B. The unconditioned stimulus becomes associated with a new response
• C. The conditioned response intensifies with repeated CS-US pairings
• D. The conditioned response weakens when the conditioned stimulus is presented without the unconditioned stimulus

Answer: (D)

Extinction in classical conditioning occurs when the conditioned response weakens because the conditioned stimulus is repeatedly presented without the unconditioned stimulus. Think of a bell that used to predict food. If the bell rings many times and no food follows, the dog stops salivating as strongly to the bell. The learning is that the bell no longer signals the food, so the response drops. It’s important to realize this doesn’t wipe out the original learning completely; the association remains, but a new learning layer suppresses the response. If the animal is later re-exposed to the CS alone after a break, the response can reappear, sometimes suddenly (spontaneous recovery) or in new contexts (renewal).