as a student talks to her psychology professor, the professor explains that the way she usually conducts research is by measuring the frequency of lever presses by rats, and examining how different kinds of rewards and punishments increase or decrease the frequency of the lever presses. she also explains that according to the theory she works to test, there is little to no need to appeal to how the rats’ "minds" are working. rather, she can explain all lever-pressing simply as a function of the external environment in which the rat finds itself. the professor comes from the perspective.