Emotional Valence and the Free-Energy Principle

TLDR

The free‑energy principle offers a unified Bayesian account of perception, learning, and action, yet emotion—particularly the core concept of valence—has not yet been incorporated into this framework. The paper proposes defining emotional valence as the negative rate of change of free‑energy over time. This definition is derived by modeling valence as the negative time derivative of free‑energy. By incorporating the second time‑derivative of free‑energy, the model accounts for basic emotions such as happiness, fear, and relief, and shows that negative valence increases learning rates when expectations are violated while positive valence decreases learning rates when expectations are fulfilled, underscoring emotions’ role in adapting to unexpected changes.

Abstract

The free-energy principle has recently been proposed as a unified Bayesian account of perception, learning and action. Despite the inextricable link between emotion and cognition, emotion has not yet been formulated under this framework. A core concept that permeates many perspectives on emotion is valence, which broadly refers to the positive and negative character of emotion or some of its aspects. In the present paper, we propose a definition of emotional valence in terms of the negative rate of change of free-energy over time. If the second time-derivative of free-energy is taken into account, the dynamics of basic forms of emotion such as happiness, unhappiness, hope, fear, disappointment and relief can be explained. In this formulation, an important function of emotional valence turns out to regulate the learning rate of the causes of sensory inputs. When sensations increasingly violate the agent's expectations, valence is negative and increases the learning rate. Conversely, when sensations increasingly fulfil the agent's expectations, valence is positive and decreases the learning rate. This dynamic interaction between emotional valence and learning rate highlights the crucial role played by emotions in biological agents' adaptation to unexpected changes in their world.