Final answer:
The procedure described where Paul associates nausea with smoking after receiving an injection of a nausea-inducing drug is an example of aversive conditioning. This technique is used to reduce undesirable behaviors by pairing them with unpleasant stimuli.
Step-by-step explanation:
The example of Paul receiving an injection of a nausea-inducing drug followed by smoking a cigarette best demonstrates the procedures typically used in aversive conditioning. This form of conditioning involves pairing an undesirable behavior with an unpleasant stimulus, in the hopes that the discomfort associated with the stimulus will reduce the frequency of the behavior. This is different from systematic desensitization, client-centered therapy, or rational emotive therapy, which approach behavior change in different ways. A real-world example of aversive conditioning is a cancer patient developing nausea as a conditioned response when seeing a syringe, after associating it with the nausea experienced due to chemotherapy treatment.
Another approach to changing smoking behavior is adding a new cognition like "Smoking suppresses my appetite, which is good for my health" to rationalize the habit. It's also worth noting that conditioning can occur based on single instances and that classical conditioning strategies can help with challenges such as reducing the negative effects of cancer treatment-induced nausea.