What does the term conditioned stimulus refer to?

The term conditioned stimulus refers specifically to a neutral stimulus that, after being paired repeatedly with an unconditioned stimulus, comes to elicit a conditioned response. In the classical conditioning paradigm, the process begins with a neutral stimulus that does not naturally provoke a response. However, when this stimulus is presented alongside an unconditioned stimulus—one that naturally and predictably causes a response—it eventually becomes associated with that response. Thus, after sufficient pairing, the previously neutral stimulus transforms into a conditioned stimulus capable of triggering a similar response on its own, known as the conditioned response. This fundamental concept is central to understanding how associations are formed through classical conditioning.