 In what has come to be the most philosophically developed version of this Bayesian approach to the mind (Hohwy, 2013, Clark, 2013), cognition as a whole is understood to be a process of Bayesian updating, in which a hierarchically-organized series of hypotheses is constantly being tested, with each hypothesis being updated in the light of evidence coming from the level below. Advocates of this theory attempt to find room within this hierarchical framework for all aspects of cognition, including perception, thought, and action. A central claim of their theory is that the information that gets passed up through this hierarchy is encoded in the form of signals representing the errors in the predictions that have been made by hypotheses at the hierarchy’s next level up, with the content of one’s experience at any time being given by whichever hypothesis makes the least erroneous predictions. (Different versions of the theory use different techniques to calculate the relative size of these prediction errors.) Given their commitment to prediction-error coding, a central claim of these theories is that the role of our sensory encounter with the world is to provide information about the way in which our prior hypotheses get things wrong: instead of providing us with the information that it has started to rain, our senses provide only the information that it is more rainy than we had expected.