The First Prior: from Co-Embodiment to Co-Homeostasis in Early Life

The idea that whatever we perceive now is influenced by whatever we perceived before lies at the core of Predictive Processing (PP) theories in philosophy and computational neuroscience. If this is so, then it becomes crucial to look at how perception, cognition and actions get off the ground from square one, in utero. Here we examine how humans self-regulate their homeostatic bodily states and build their most basic self- and world-model, literally through others’ bodies, in utero. Indeed, one basic yet overlooked aspect of current embodied and PP approaches is that brains (and minds), and human bodies, first develop within another human body. Crucially, while not all humans will have the experience of being pregnant or carrying a baby, the experience of being carried and growing within another person’s body is universal. Specifically, we define in utero development as a process co-embodiment and co-homeostasis, and highlight their close relationship. We show that the case of pregnancy offers a clear and fundamental example of co-embodiment, building upon theoretical and empirical work tackling the emergence of perceptual experiences in utero. We focus on pregnancy, a case where two individuating organisms literally grasp/ grip one into each other. Contrary to the common view of the foetus being passively ‘contained’ and solipsistically ‘trapped’ in the solitude of the womb, we will present evidence speaking in favour of an active and bidirectional co-regulation between the two living bodies, what we will call co-homeostasis. The co-embodiment and co-homeostasis theses will lay the preliminary ground for introducing a predictive processing reading of in utero development of perceptual experiences.We conclude that when it comes to understanding the nature of predictive perceptions, the infant is father to the human - to paraphrase the famous Wordsworth metaphor.