Final answer:
In operant conditioning, the research by Fantino and Case found that a stimulus linked to negative reinforcement maintained human observing, while one linked to positive punishment did not.
Step-by-step explanation:
In operant conditioning, positive and negative reinforcements are used to increase the likelihood of a behavior, while positive and negative punishments are used to decrease the likelihood of a behavior. The research conducted by Fantino and Case (1983) found that a stimulus correlated with negative reinforcement maintained human observing, but one linked to positive punishment did not.