Which term describes a stimulus that naturally elicits a response without prior learning?

Which term describes a stimulus that naturally elicits a response without prior learning?

• A. Neutral Stimulus (NS)
• B. Unconditioned Stimulus (US)
• C. Conditioned Stimulus (CS)
• D. Conditioned Response (CR)

Answer: (B)

In classical conditioning, a stimulus that naturally elicits a response without prior learning is the unconditioned stimulus. It triggers an automatic, reflexive reaction—like food reliably causing a hungry dog to salivate—without any training. The unconditioned stimulus is the natural trigger behind the reflex, not something learned through association. A neutral stimulus is something that initially does not provoke the response; after repeated pairing with the unconditioned stimulus, it becomes a conditioned stimulus that can elicit a learned response. The learned reaction to that conditioned stimulus is the conditioned response.

In classical conditioning, a stimulus that naturally elicits a response without prior learning is the unconditioned stimulus. It triggers an automatic, reflexive reaction—like food reliably causing a hungry dog to salivate—without any training. The unconditioned stimulus is the natural trigger behind the reflex, not something learned through association. A neutral stimulus is something that initially does not provoke the response; after repeated pairing with the unconditioned stimulus, it becomes a conditioned stimulus that can elicit a learned response. The learned reaction to that conditioned stimulus is the conditioned response.