Final answer:
The conditioned stimulus in Leah's case is the yard where she was stung by a bee, and through classical conditioning, she has come to associate the yard with the anxiety of getting stung, resulting in a conditioned response of panic.
Step-by-step explanation:
In the scenario where Leah becomes panicky each time she goes out to play after being stung by a bee, the conditioned stimulus is the outdoor environment of the yard where she was playing when she got stung. Previously neutral and unrelated to the pain of a bee sting, the yard has become associated with the anxiety of getting stung again, much like how Pavlov's dogs were conditioned to associate the sound of a bell with receiving food. Leah's anxiety is a conditioned response to the conditioned stimulus of the yard, a reaction which has developed as a result of classical conditioning.
Classical conditioning occurs when a neutral stimulus becomes associated with a significant event and, as a result, takes on new meaning and elicits a specific response. In this case, Leah's anxiety is not a direct result of the yard itself, but rather the association her mind has created between the yard and the unpleasant experience of being stung by a bee. This is an example of how classical conditioning can affect behavior in humans.