A conditioned response is a learned reaction to a specific stimulus that occurs through a process called classical conditioning. This concept was famously demonstrated by Ivan Pavlov, who trained dogs to salivate at the sound of a bell. Initially, the bell had no effect, but after being paired repeatedly with food, the dogs began to associate the sound with receiving food, leading to the salivation response. In essence, a conditioned response occurs when an organism learns to connect a neutral stimulus with an unconditioned stimulus that naturally elicits a response. This learning process helps organisms adapt to their environment by anticipating events based on previous experiences.