Alessandro Monti writes:

Think back to a recent episode in which you felt as if you were being true to yourself. How would you describe what you did? Perhaps you would say that you ‘trusted your guts’ or ‘followed your heart’, rather than ‘thinking with your head’. You might also assume that these idioms involving the guts or the heart belong to an outdated folklore – that they are a poetic rather than a scientific expression of what’s happening when we tap into our sense of self. Yet, emerging scientific evidence increasingly suggests that being aware of who you are – being self-conscious – really does depend, not just on processes in your brain, but also on what’s happening deep in your viscera.

Consider how, right now, you could be in a very different place, mood or situation than 20 seconds or 20 years ago, yet you feel that in a fundamental sense you are the same person. This is partly because, as William James put it in The Principles of Psychology (1890), you are aware that ‘the same old body’ is always with you, exuding warmth and intimacy. With the exception of dreaming and altered states of mind, all conscious experiences entail this subtle but pervasive feeling of bodily self-consciousness. But where does it come from? The feeling cannot merely stem from the outward look of the body, because you could spend a great deal of time and money to change your appearance without feeling like a different self (no matter how hard hairdressers and designers try to convince you otherwise). Rather, the bodily basis of your stable self must spring from a steadier source. And since the body is felt not just from without, but also from within, your internal organs could be one such source.

Indeed, a remarkable feature of visceral organs is the fact that they go through steady, predictable physiological cycles. Heartbeats, breaths and gut contractions repeat themselves with regularity, keeping the body warm and fed – a physiological equilibrium known as homeostasis. Moreover, each of these cycles involves peripheral nerves – especially the vagus nerve – sending chemical and electrical signals to the central nervous system. As a result, the activity of specific regions of the central nervous system synchronises with cardiac, respiratory and gastric fluctuations. While sensory impressions coming from the external environment vary from moment to moment and fade away, this coupling between brain and viscera is a permanent feature of your physiology. You can close your eyes, cover your ears, hold your nose or seal your mouth, but you cannot cut yourself off from your bowels. Everything changes around you, but your internal organs are always there, always broadcasting signals to the brain, always playing their thorough bass in the grand music of life. The inner side of the body is the only object that you cannot stop receiving information about, the only object you always feel from the beginning to the end of your days. Thus, internal organs are a prime candidate as a basis for building and maintaining your sense of selfhood across time. [Continue reading…]