A sense of self

Communication between the brain and other organs shapes how we think, remember, and feel. Scientists are unraveling how our organs talk to the brain and how the brain talks back. That two-way communication, known as interoception, encompasses a complex system of nerves and hormones, including the vagus nerve, a massive network of fibers that travel from nearly every internal organ to the base of the brain and back again. Scientist have long known the vagus nerve carries signals between the organs and the brainstem. But new studies show signals carried by the vagus climb beyond the brainstem and into brain regions involved in memory, emotion, and decision-making. The research is challenging traditional distinctions between disorders of the brain and body, and may even hold clues to the nature of consciousness.