Abstract

In this Thesis, I systematize, clarify, and expand the current theory of emotion based on the principles of predictive processing—the interoceptive inference view of emotion—so as to show the following: as it stands, this view is problematic. Once expanded, the view in question can deal with its more pressing problems, and it compares favourably to competing accounts. Thus, the interoceptive inference view of emotion stands out as a plausible theory of emotion. According to the predictive processing framework, all what the brain does, in all its functions, is to minimize its precision-weighted prediction error. Roughly, PE consist in the difference between the sensory signals expected from the top-down and the actual, incoming sensory signals. Now, in the PP framework, visual percepts are formed by minimizing visual PE in a specific manner: via visual perceptual inference. That is, the brain forms visual percepts in a top-down fashion by predicting its incoming lower-level sensory signals from higher-level models of the likely causes of those visual signals. Such models can be seen as putting forward content-specifying hypotheses about the object or event responsible for triggering incoming sensory activity. A contentful percept is formed once a certain hypothesis achieves to successfully match, and thus supress, current lower-level sensory signals. In the interoceptive inference approach to interoception, the principles of PP have been extended to account for interoception, i.e., the perception of our homeostatic, physiological condition. Just as perception in the visual domain arises via visual perceptual inference, the interoceptive inference approach holds that perception of the inner, physiological milieu arises via interoceptive perceptual inference. Now, what might be called the interoceptive inference theory of valence holds that the interoceptive inference approach can be used so as to account for subjective feeling states in general, i.e., mental states that feel good or bad—i.e., valenced mental states. According to ITV, affective valence arises by way of interoceptive perceptual inference. On the other hand, what might be called the interoceptive inference view of emotion holds that the interoceptive inference approach can be used so as to account for emotions per se. More precisely, IIE holds that, in direct analogy to the way in which visual percepts are formed, emotions arise from interoceptive predictions of the causes of current interoceptive afferents. In other words, emotions per se amount to interceptive percepts formed via higher-level, content-specifying emotion hypotheses. In this Thesis, I aim to systematize, clarify, and expand the interoceptive inference approach to interoception, in order to show that: contrary to non-sensory theories of affective valence, valence is indeed constituted by interoceptive perceptions, and that interoceptive percepts do arise via interoceptive perceptual inference. Therefore, ITV holds. Considering that IIE exhibits problematic assumptions, it should be amended. In this respect, I will argue that emotions do not arise via interoceptive perceptual inference, since this assumes that there must be regularities pertaining to emotion in the physiological domain. I will suggest that emotions arise instead by minimizing interoceptive PE in another fashion. That is, emotions arise via external interoceptive active inference: by sampling and modifying the external environment in order to change an already formed interoceptive percept. That is, emotions are specific strategies for regulating affective valence. More precisely, I will defend the view that a certain emotion E amounts to a specific strategy for minimizing interoceptive PE by way of a specific set of stored knowledge of the counterfactual relations that obtain between actions and its prospective interoceptive, sensory consequences. An emotion arises when such knowledge is applied in order to regulate valence.