The word "oblongata" refers to a part of the brain located near the spinal cord. It helps control vital functions like breathing, heart rate, and blood pressure. Full definition
(not to ruin a good story, but the medulla oblongata helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing. (sbnation.com)
That is to say my tribesmen know the difference between instinct, intelligence and intuition though they do not know it comes from different parts of the brain like Medula oblongata, cerebrum and cerebellum. (religion.blogs.cnn.com)