SECTION 3 Directions: Each passage in this group is followed by questions based on its content. After reading a passage, choose the best answer to each question. Answer all questions following a passage on the basis of what is stated or implied in the passage. Behavioral psychologists apprehend that conditioned fear responses to a tone previously paired with a shock diminish, if the tone is repeatedly presented without the shock, a process known as extinction. Since Parlor it has been hypothesized that this extinction does not erase conditioning, but forms a new (5) memory. Research has now demonstrated that destruction of the infralimbic cortice blocks recall of fear extinction, indicating that it might store long-term extinction memory. Infralimbic neurons recorded during fear conditioning and extinction fire to the tone only when rats are recalling extinction on the following day, and rats indicating the least fear responses also demonstrate the (10) greatest increase in infralimbic tone responses. Conditioned tones paired with brief electrical stimulation of infralimbic cortex elicit low fear responses in rats that have not undergone extinction. Thus, stimulation resembling extinction-induced infralimbic tone responses is able to simulate extinction memory. According to the passage, behavioral psychologists studying the extinction process have discerned which of the following?