Pleasure

Pleasure is a broad class of mental states that humans and other animals experience as positive, enjoyable, or worth seeking. It includes more specific mental states such as happiness, entertainment, enjoyment, ecstasy, and euphoria. The early psychological concept of pleasure, the pleasure principle, describes it as a positive feedback mechanism that motivates the organism to recreate the situation it has just found pleasurable, and to avoid past situations that caused pain. Pleasure is a broad class of mental states that humans and other animals experience as positive, enjoyable, or worth seeking. It includes more specific mental states such as happiness, entertainment, enjoyment, ecstasy, and euphoria. The early psychological concept of pleasure, the pleasure principle, describes it as a positive feedback mechanism that motivates the organism to recreate the situation it has just found pleasurable, and to avoid past situations that caused pain. The experience of pleasure is subjective and different individuals experience different kinds and amounts of pleasure in the same situation. Many pleasurable experiences are associated with satisfying basic biological drives, such as eating, exercise, hygiene, sleep, and sex. The appreciation of cultural artifacts and activities such as art, music, dancing, and literature is often pleasurable. Based upon the incentive salience model of reward – the attractive and motivational property of a stimulus that induces approach behavior and consummatory behavior – an intrinsic reward has two components: a 'wanting' or desire component that is reflected in approach behavior, and a 'liking' or pleasure component that is reflected in consummatory behavior. While all pleasurable stimuli are rewards, some rewards do not evoke pleasure. Pleasure is a component of reward, but not all rewards are pleasurable (e.g., money does not elicit pleasure unless this response is conditioned). Stimuli that are naturally pleasurable, and therefore attractive, are known as intrinsic rewards, whereas stimuli that are attractive and motivate approach behavior, but are not inherently pleasurable, are termed extrinsic rewards. Extrinsic rewards (e.g., money) are rewarding as a result of a learned association with an intrinsic reward. In other words, extrinsic rewards function as motivational magnets that elicit 'wanting', but not 'liking' reactions once they have been acquired. The reward system contains pleasure centers or hedonic hotspots – i.e., brain structures that mediate pleasure or 'liking' reactions from intrinsic rewards. As of October 2017, hedonic hotspots have been identified in subcompartments within the nucleus accumbens shell, ventral pallidum, parabrachial nucleus, orbitofrontal cortex (OFC), and insular cortex. The hotspot within the nucleus accumbens shell is located in the rostrodorsal quadrant of the medial shell, while the hedonic coldspot is located in a more posterior region. The posterior ventral pallidum also contains a hedonic hotspot, while the anterior ventral pallidum contains a hedonic coldspot. Microinjections of opioids, endocannabinoids, and orexin are capable of enhancing liking in these hotspots. The hedonic hotspots located in the anterior OFC and posterior insula have been demonstrated to respond to orexin and opioids, as has the overlapping hedonic coldspot in the anterior insula and posterior OFC. On the other hand, the parabrachial nucleus hotspot has only been demonstrated to respond to benzodiazepine receptor agonists. Hedonic hotspots are functionally linked, in that activation of one hotspot results in the recruitment of the others, as indexed by the induced expression of c-Fos, an immediate early gene. Furthermore, inhibition of one hotspot results in the blunting of the effects of activating another hotspot. Therefore, the simultaneous activation of every hedonic hotspot within the reward system is believed to be necessary for generating the sensation of an intense euphoria. Pleasure is considered one of the core dimensions of emotion. It can be described as the positive evaluation that forms the basis for several more elaborate evaluations such as 'agreeable' or 'nice'. As such, pleasure is an affect and not an emotion, as it forms one component of several different emotions. Pleasure is sometimes subdivided into fundamental pleasures that are closely related to survival (food, sex, and social belonging) and higher-order pleasures (e.g., viewing art and altruism). The clinical condition of being unable to experience pleasure from usually enjoyable activities is called anhedonia. An active aversion to obtaining pleasure is called hedonophobia. Pleasure is often regarded as a bipolar construct, meaning that the two ends of the spectrum from pleasant to unpleasant are mutually exclusive. This view is e.g. inherent in the circumplex model of affect. Yet, some lines of research suggest that people do experience pleasant and unpleasant feelings at the same time, giving rise to so-called mixed feelings. The degree to which something or someone is experienced as pleasurable not only depends on its objective attributes (appearance, sound, taste, texture, etc.), but on beliefs about its history, about the circumstances of its creation, about its rarity, fame, or price, and on other non-intrinsic attributes, such as the social status or identity it conveys. For example, a sweater that has been worn by a celebrity is more desired than an otherwise identical sweater that has not, though considerably less so if it has been washed. Another example was when Grammy-winning, internationally acclaimed violinist Joshua Bell played in the Washington D.C. subway for 43 minutes, attracting little attention from the 1,097 people who passed by, and earning about $59 in tips. Paul Bloom describes these phenomena as arising from a form of essentialism.