A 54-year-old man comes to the physician for a follow-up examination 10 days after undergoing a stereotactic brain operation to remove a small tumor. The operation was successful. During the procedure, he was under conscious sedation.Which of the following areas of the brain was most likely stimulated when the patient experienced a sudden, intense feeling of overwhelming fear during the stereotactic brain operation? 1) Frontal lobe 2) Temporal lobe 3) Occipital lobe 4) Amygdala