Mathematical Modeling of Emotion Potential and Pleasure Based on the Dynamics of Free Energy

– Verification Using Experimental Data of Musical Pleasures –

抄録

Appropriate levels of arousal potential evoke hedonic responses. Yanagisawa, the second author, previously proposed a mathematical model of emotional arousal caused by novelty, uncertainty, and complexity using information-theoretic free energy. In this study, we formulate the information processing flow in the brain based on the dynamics of free energy to represent both emotional arousal and pleasure caused by the reduction of free energy. We hypothesized that free-energy reduction is proportional to a positive emotion such as pleasure and that the state of free energy meaning arousal potential forms an inverse U-shaped function of the valence. We verified proposing model prediction using the experimental data given by a previous study of musical pleasure. By using a statistical learning model of music, we calculated the free energy of perceiving the progression of harmonies as sensory stimuli. The results partially reflect our hypotheses and revealed the two: displeasure due to large arousal potential and pleasure due to large free-energy reduction.