What is the term for the automatic response to a stimulus that occurs without prior learning?

The term that describes the automatic response to a stimulus occurring without prior learning is "Unconditioned Response." This concept is rooted in classical conditioning, as introduced by Ivan Pavlov. An unconditioned response is a natural, unlearned reaction to an unconditioned stimulus. For example, when food is presented to a dog, it naturally drools. This response does not require any prior experience or learning; it is an innate reaction.

In contrast, a conditioned response would involve learning, as it refers to a response that is learned through the pairing of a neutral stimulus with an unconditioned stimulus. Reinforced behavior pertains to operant conditioning, where behavior is strengthened through rewards or reinforcement, and voluntary response refers to behaviors that are consciously controlled and not automatic. Understanding these distinctions clarifies why "Unconditioned Response" is the correct term for the automatic reaction to stimuli without previous learning.