In classical conditioning, what is the term for the stimulus that becomes capable of eliciting a response after being paired with the unconditioned stimulus?

• A. Conditioned response (CR)
• B. Unconditioned stimulus (UCS)
• C. Unconditioned response (UCR)
• D. Conditioned stimulus (CS)

Answer: (D)

The essential idea is that a neutral cue can come to trigger a response after it’s paired with something that naturally produces that response. This neutral cue becomes a conditioned stimulus because it now signals the occurrence of the unconditioned stimulus, and it can elicit the learned response on its own. For example, in Pavlov’s experiment, the bell starts off neutral; after it reliably predicts food, the bell alone begins to trigger the dog’s salivation—the conditioned response—even when no food is present. The unconditioned stimulus is the thing that naturally causes the reflex (food), and the unconditioned response is the reflex itself (salivation to food). The conditioned response is the learned reaction to the conditioned stimulus (salivation to the bell).