Final answer:
In Pavlov's experiment, the bell served as the neutral stimulus. Through the process of classical conditioning, it became a conditioned stimulus after being repeatedly paired with the unconditioned stimulus (food), leading to a conditioned response (salivation) in the dogs.
Step-by-step explanation:
In Pavlov's study, the neutral stimulus was a bell. Before conditioning, this stimulus did not affect the dogs' behavior. However, during conditioning, Pavlov paired the bell with the unconditioned stimulus (food), and this pairing was repeated over several trials. As a result, the previously neutral stimulus (the bell), through repeated association with food, started to elicit a conditioned response (salivation) from the dogs.
Once the conditioning period was concluded, the dogs had learned to associate the sound of the bell with the forthcoming food. Therefore, even in the absence of the unconditioned stimulus (food), the bell ringing alone was able to induce salivation in the dogs. Hence, the bell, initially a neutral stimulus, transitioned into being a conditioned stimulus and the salivation turned into a conditioned response.