Lisa conducts an experiment to determine if Bart is smarter than a hamster. She puts the two subjects through tests involving cupcakes. At the end of the experiment, both Bart and the hamster have a negative response to seeing cupcakes.
This is actually operant conditioning, not classical conditioning, since Bart and the rat learn that their actions of touching food lead to positive punishment of getting shocked. They learn a consequence to their action = operant conditioning.
Marc Garlock