The role of hedonics in the Human Affectome

•As experiences of pleasure and displeasure, hedonics are omnipresent in daily life.•As core processes, hedonics accompany emotions, motivation, bodily states, etc.•Orbitofrontal cortex and nucleus accumbens appear to be hedonic brain hubs.•Several mental illnesses are characterized by altered hedonic experiences.•Optimal hedonic functioning seems the basis of well-being and aesthetic experiences. Experiencing pleasure and displeasure is a fundamental part of life. Hedonics guide behavior, affect decision-making, induce learning, and much more. As the positive and negative valence of feelings, hedonics are core processes that accompany emotion, motivation, and bodily states. Here, the affective neuroscience of pleasure and displeasure that has largely focused on the investigation of reward and pain processing, is reviewed. We describe the neurobiological systems of hedonics and factors that modulate hedonic experiences (e.g., cognition, learning, sensory input). Further, we review maladaptive and adaptive pleasure and displeasure functions in mental disorders and well-being, as well as the experience of aesthetics. As a centerpiece of the Human Affectome Project, language used to express pleasure and displeasure was also analyzed, and showed that most of these analyzed words overlap with expressions of emotions, actions, and bodily states. Our review shows that hedonics are typically investigated as processes that accompany other functions, but the mechanisms of hedonics (as core processes) have not been fully elucidated.