The role of oxytocin in delay of gratification and flexibility in non-social decision making.

Oxytocin is well-known for its impact on social cognition. This specificity for the social domain, however, has been challenged by findings suggesting a domain-general allostatic function for oxytocin by promoting future-oriented and flexible behavior. In this pre-registered study, we tested the hypothesized domain-general function of oxytocin by assessing the impact of intranasal oxytocin (24 IU) on core aspects of human social (inequity aversion) and non-social decision making (delay of gratification and cognitive flexibility) in 49 healthy volunteers (within-subject design). In intertemporal choice, patience was higher under oxytocin than under placebo, although this difference was evident only when restricting the analysis to the first experimental session (between-group comparison) due to carry-over effects. Further, oxytocin increased cognitive flexibility in reversal learning as well as generosity under conditions of advantageous but not disadvantageous inequity. Our findings show that oxytocin affects both social and non-social decision making, supporting theoretical accounts of domain-general functions of oxytocin.

A role for endogenous opiates in incubation behavior in ring neck doves (Streptopelia risoria).

Incubation of eggs is a critical component of parental care in avian species. However, we do not fully understand the neuroendocrine mechanisms underlying this vital behavior. While prolactin is clearly involved, it alone cannot explain the fine-tuning of incubation behavior. The present experiments explored the possibility that incubation is reinforced through a hedonic system in which contact with eggs elicited an opiate-mediated reinforcing state. Blockade of opiate receptors with naloxone reduced time ring neck doves (Streptopelia risoria) spent on the nest, possibly by uncoupling the opiate-receptor mediated hedonic experience of contact with eggs from nest-sitting behavior. Likewise, activation of opiate receptors with morphine also reduced time spent on the nest, possibly by activating an opiate-receptor mediated hedonic experience, hence rendering the eliciting behavior (contact with eggs) unnecessary. Taken together, the results suggest that the opiate system may play a previously unrecognized role in facilitating incubation through reinforcement.

Dopaminergic and opioidergic regulation during anticipation and consumption of social and nonsocial rewards.

The observation of animal orofacial and behavioral reactions has played a fundamental role in research on reward but is seldom assessed in humans. Healthy volunteers (N = 131) received 400 mg of the dopaminergic antagonist amisulpride, 50 mg of the opioidergic antagonist naltrexone, or placebo. Subjective ratings, physical effort, and facial reactions to matched primary social (affective touch) and nonsocial (food) rewards were assessed. Both drugs resulted in lower physical effort and greater negative facial reactions during reward anticipation, especially of food rewards. Only opioidergic manipulation through naltrexone led to a reduction in positive facial reactions to liked rewards during reward consumption. Subjective ratings of wanting and liking were not modulated by either drug. Results suggest that facial reactions during anticipated and experienced pleasure rely on partly different neurochemical systems, and also that the neurochemical bases for food and touch rewards are not identical.

Studies in rats and other species have shown that two chemical messengers in the brain regulate how much an animal desires a reward, and how pleasant receiving the reward is. In this context, chemicals called opioids control both wanting and enjoying a reward, whereas a chemical called dopamine only regulates how much an animal desires it. However, since these results were obtained from research performed on animals, further studies are needed to determine if these chemicals play the same roles in the human brain. Korb et al. show that the same brain chemicals that control reward anticipation and pleasure in rats are also at work in humans. In the experiment, 131 healthy volunteers received either a drug that blocks opioid signaling in the brain, a drug that blocks dopamine signaling, or a placebo, a pill with no effect. Then, participants were given, on several occasions, either sweet milk with chocolate or a gentle caress on the forearm. Participants rated how much they wanted each of the rewards before receiving it, and how much they liked it after experiencing it. To measure their implicit wanting of the reward, participants also pressed a force-measuring device to increase their chances of receiving the reward. Additionally, small electrodes measured the movement of the volunteer's smiling or frowning muscles to detect changes in facial expressions of pleasure. Volunteers taking either drug pressed on the device less hard than the participants taking the placebo, suggesting they did not want the rewards as much, and they frowned more as they anticipated the reward, indicating less anticipatory pleasure. However, only the volunteers taking the opioid-blocking drug smiled less when they received a reward, indicating that these participants did not get as much pleasure as others out of receiving it. These differences were most pronounced when volunteers looked at or received the sweet milk with chocolate. This experiment helps to shed light on the chemicals in the human brain that are involved in reward-seeking behaviors. In the future, the results may be useful for developing better treatments for addictions.

Consuming Gymnema sylvestre Reduces the Desire for High-Sugar Sweet Foods.

Background. Gymnemic acids, from the plant Gymnema sylvestre (GS), selectively suppress taste responses to sweet compounds without affecting the perception of other taste elements. The aim of this study was to investigate the effect of consuming a GS-containing mint on the desire to consume high-sugar sweet foods directly thereafter. Methods. This study utilized a single-blind, crossover design comparing the consumption of a mint (dissolving tablet) containing 4 mg of gymnemic acids with an isocaloric placebo in 56 healthy young men and women. Participants were given samples of their favourite chocolate (varied between 14-18 g; energy varied between 292-370 kJ) and were directed to rate on their hunger on 100-mm visual analogue scales 30 s prior to consuming high-sugar sweet food (chocolate). They then consumed the GS mint or placebo mint and rated their perceived pleasantness and desire for more chocolate on separate visual analogue scales immediately following consumption of the high-sugar sweet food before being offered up to five additional servings (and asked to rate hunger, pleasantness and desire to eat more chocolate between each ingestion period). Results. The number of chocolate bars eaten decreased by 0.48 bars (21.3%) within a 15-min period of consumption of the GS mint (p = 0.006). Desire to eat more of the high-sugar sweet food (p = 0.011) and pleasantness of the high-sugar sweet food (p < 0.001) was reduced after GS mint intake. Those who reported having a 'sweet tooth' had a greater reduction in the pleasantness of chocolate (p = 0.037) and desire to eat more (p = 0.004) after consuming the GS mint for the first serving of a high-sugar sweet food following the mint. Conclusion. Consuming gymnema-containing mints compared to placebo significantly reduced the quantity of chocolate eaten mainly due to a decrease in the desire and pleasantness of consuming it.

Anhedonia in chronic pain and prescription opioid misuse.

BACKGROUND: Both acute and chronic pain can disrupt reward processing. Moreover, prolonged prescription opioid use and depressed mood are common in chronic pain samples. Despite the prevalence of these risk factors for anhedonia, little is known about anhedonia in chronic pain populations. METHODS: We conducted a large-scale, systematic study of anhedonia in chronic pain, focusing on its relationship with opioid use/misuse, pain severity, and depression. Chronic pain patients across four distinct samples (N = 488) completed the Snaith-Hamilton Pleasure Scale (SHAPS), measures of opioid use, pain severity and depression, as well as the Current Opioid Misuse Measure (COMM). We used a meta-analytic approach to determine reference levels of anhedonia in healthy samples spanning a variety of countries and diverse age groups, extracting SHAPS scores from 58 published studies totaling 2664 psychiatrically healthy participants. RESULTS: Compared to healthy samples, chronic pain patients showed higher levels of anhedonia, with ~25% of patients scoring above the standard anhedonia cut-off. This difference was not primarily driven by depression levels, which explained less than 25% of variance in anhedonia scores. Neither opioid use duration, dose, nor pain severity alone was significantly associated with anhedonia. Yet, there was a clear effect of opioid misuse, with opioid misusers (COMM ⩾13) reporting greater anhedonia than non-misusers. Opioid misuse remained a significant predictor of anhedonia even after controlling for pain severity, depression and opioid dose. CONCLUSIONS: Study results suggest that both chronic pain and opioid misuse contribute to anhedonia, which may, in turn, drive further pain and misuse.

Anticipation of monetary reward in amygdala, insula, caudate are predictors of pleasure sensitivity to d-Amphetamine administration.

BACKGROUND: Drug addiction and dependence continue as an unresolved source of morbidity and mortality. Two approaches to identifying risk for abuse and addiction are psychopharmacological challenge studies and neuroimaging experiments. The present study combined these two approaches by examining associations between self-reported euphoria or liking after a dose of d-amphetamine and neural-based responses to anticipation of a monetary reward. METHODS: Healthy young adults (N = 73) aged 19 and 26, without any history of alcohol/substance dependence completed four laboratory sessions in which they received oral d-amphetamine (20 mg) or placebo, and completed drug effect questionnaires. On a separate session they underwent a functional magnetic resonance imaging scan while they completed a monetary incentive delay task. During the task, we recorded neural signal related to anticipation of winning $5 or $1.50 compared to winning no money (WinMoney-WinZero), in reward related regions. RESULTS: Liking of amphetamine during the drug sessions was related to differences in activation during the WinMoney-WinZero conditions - in the amygdala (positive), insula (negative) and caudate (negative). In posthoc analyses, liking of amphetamine was also positively correlated with activation of the amygdala during anticipation of large rewards and negatively related to activation of the left insula to both small and large anticipated rewards. CONCLUSIONS: These findings suggest that individual differences in key regions of the reward network are related to rewarding subjective effects of a stimulant drug. To further clarify these relationships, future pharmacofMRI studies could probe the influence of amphetamine at the neural level during reward anticipation.

Effects of MDMA on attention to positive social cues and pleasantness of affective touch.

The psychostimulant drug ±3,4-methylenedioxymethamphetamine (MDMA) reportedly produces distinctive feelings of empathy and closeness with others. MDMA increases social behavior in animal models and has shown promise in psychiatric disorders, such as autism spectrum disorder (ASD) and post-traumatic stress disorder (PTSD). How it produces these prosocial effects is not known. This behavioral and psychophysiological study examined the effects of MDMA, compared with the prototypical stimulant methamphetamine (MA), on two measures of social behavior in healthy young adults: (i) responses to socially relevant, "affective" touch, and (ii) visual attention to emotional faces. Men and women (N = 36) attended four sessions in which they received MDMA (0.75 or 1.5 mg/kg), MA (20 mg), or a placebo in randomized order under double-blind conditions. Responses to experienced and observed affective touch (i.e., being touched or watching others being touched) were assessed using facial electromyography (EMG), a proxy of affective state. Responses to emotional faces were assessed using electrooculography (EOG) in a measure of attentional bias. Subjective ratings were also included. We hypothesized that MDMA, but not MA, would enhance the ratings of pleasantness and psychophysiological responses to affective touch and increase attentional bias toward positive facial expressions. Consistent with this, we found that MDMA, but not MA, selectively enhanced ratings of pleasantness of experienced affective touch. Neither drug altered the ratings of pleasantness of observed touch. On the EOG measure of attentional bias, MDMA, but not MA, increased attention toward happy faces. These results provide new evidence that MDMA can enhance the experience of positive social interactions; in this case, pleasantness of physical touch and attentional bias toward positive facial expressions. The findings are consistent with evidence that the prosocial effects are unique to MDMA relative to another stimulant. Understanding the behavioral and neurobiological processes underlying the distinctive social effects of MDMA is a key step to developing the drug for psychiatric disorders.

Ventromedial prefrontal cortex is involved in preference and hedonic evaluation of tastes.

The ventromedial prefrontal cortex (vmPFC) of rats has reciprocal connections with the gustatory and the hedonic impact coding structures. The main goal of the present study was to investigate the involvement of local neurons of vmPFC and their catecholaminergic innervations in taste preference and taste reactivity test. Therefore, kainate or 6-hydroxydopamine (6-OHDA) lesions were performed in the vmPFC by iontophoretic method. In the first experiment, taste preference was tested to 250 mM and 500 mM glucose solutions over water in two-bottle choice test. In the second experiment, taste reactivity was examined to 4 concentrations of glucose solutions (250 mM, 500 mM, 750 mM and 1000 mM) and 4 concentrations of quinine solutions (0.125 mM, 0.25 mM, 1.25 mM and 2.5 mM). Our results showed, that kainate microlesion of vmPFC did not modify the preference of 250 mM and 500 mM glucose solutions in two-bottle choice test. In contrast, 6-OHDA microlesion of vmPFC resulted in increased preference to the higher concentration of glucose (500 mM) solution over water. Results of taste reactivity test showed that kainate lesion resulted in more ingestive and less rejective responses to 750 mM glucose solution and elevated rejectivity to the higher concentrations (1.25 mM and 2.5 mM) of quinine solutions. 6-OHDA lesion of vmPFC increased the number of ingestive responses to highly concentrated (500 mM, 750 mM and 1000 mM) glucose solutions and decreased the number of ingestive responses to the lower concentration (0.125 mM) of quinine solution. The present data provide evidence for the important role of vmPFC neurons and catecholaminergic innervation of the vmPFC in the regulation of hedonic evaluation of tastes and in the hedonic consummatory behavior.

Psychotic-like experiences with cannabis use predict cannabis cessation and desire to quit: a cannabis discontinuation hypothesis.

BACKGROUND: Evidence suggests that cannabis-induced psychotic-like experiences may be a marker of psychosis proneness. The effect of such experiences on cannabis use has not systematically been examined. METHODS: We undertook a mixed-methods online survey of 1231 cannabis users (including 926 continued users) using the Cannabis Experiences Questionnaire. We examined the effect of psychotic-like and pleasurable experiences on cessation of cannabis and intention to quit. Socio-demographic variables, cannabis use parameters and substance misuse history were included as covariates. Free-text data explored subjective reasons for changes in use. RESULTS: Cessation of cannabis use was associated with greater psychotic-like experiences [p < 0.001, Exp(B) 1.262, 95% confidence interval (CI) 1.179-1.351], whilst continued cannabis users were more likely to report pleasurable experiences [p < 0.001, Exp(B) 0.717, 95% CI 0.662-0.776]. Intention to quit cannabis in continued users was associated with greater psychotic-like experiences [p < 0.003, Exp(B) 1.131, 95% CI 1.044-1.225], whilst intention to not quit was significantly associated with increased pleasurable experiences [p < 0.015, Exp(B) 0.892, 95% CI 0.814-0.978]. Whereas former users clearly ascribed cessation to negative experiences, continued users who expressed intention to quit less readily ascribed the intention to negative experiences. CONCLUSIONS: Elucidation of psychotic-like experiences may form the basis of a therapeutic intervention for those who wish to quit. Cessation in those with cannabis-induced psychotomimetic experiences may offset the risk for the development of a psychotic disorder, in this higher risk group.

From mundane medicines to euphorigenic drugs: How pharmaceutical pleasures are initiated, foregrounded, and made durable.

BACKGROUND: Examining how pharmaceuticals are used to induce pleasure presents a unique opportunity for analyzing not only how pleasure is assembled and experienced through distinct consumption practices but also how mundane medicines can become euphorigenic substances. METHODS: Drawing on qualitative research on the non-medical use of prescription drugs by young adults in the United States, this paper utilizes Actor-Network Theory (ANT) to examine how prescription medicines come to produce pleasure. RESULTS: Our research found an indeterminacy of experience as individuals were initiated into prescription drug pleasures. We also found that euphorigenic effects coalesce and are foregrounded through subsequent use, and that pleasure and other forms of gratification are made durable through repeated and deliberate pharmaceutical consumption. CONCLUSION: Understanding how individuals are socialized into pharmaceutical pleasure, and how assemblages act to constitute the euphorigenic potential of pharmaceutical misuse, may allow for more context-appropriate intervention efforts. We suggest that the euphorigenic properties ascribed to prescription drugs are not inherent in their pharmaceutical formulations, but instead emerge through interactions within networks of heterogeneous actants.

Assessing notions of denormalization and renormalization of smoking in light of e-cigarette regulation.

The rationale for 'denormalization' of smoking in tobacco policies has been challenged by the emergence of e-cigarettes and the need to regulate e-cigarette use and promotion. Our aim is to assess the research status on e-cigarettes' contribution to 'renormalization' of smoking and to clarify how renormalization of smoking can be appraised at the conceptual and empirical level. Combining conceptual analysis and narrative review, the paper brings out three dimensions of denormalization/renormalization of smoking ('unacceptability/acceptability'; 'invisibility/visibility'; 'phasing out behaviour/maintaining behaviour') and an inherent duality of the e-cigarette as a smoking-like device and a smoking alternative. These analytical dimensions are applied qualitatively to consider the literature identified by searching the Web of Science database for 'e-cigarettes AND renormalization' (and variants thereof). Theoretically, normative changes in smoking acceptability, increased visibility of e-cigarettes and use, and observations of actual use (prevalence, dual use, gateway) can all be applied to illustrate processes of renormalization. However, only acceptability measures and user measures can be said to be empirical tests of renormalization effects. Visibility measures are only based on logical assumptions of a possible renormalization; they are not in themselves indicative of any "real" renormalization effects and can just as well be understood as possible consequences of normalization of e-cigarettes. Just as a downward trend in smoking prevalence is the litmus test of whether denormalization policy works, stagnating or rising smoking prevalence should be the main empirical indicator of renormalization.

Thinking with pleasure: Experimenting with drugs and drug research.

Within the field of drug and alcohol studies, researchers think about pleasure or against it; we analyse, consider, investigate, invoke or ignore it. The philosophically inclined may think of pleasure or write on it, but in each of these scenarios pleasure is kept at an arm's length while the researcher appears to remain unmoved - detached observers, objective scientists, conceptual experts, program directors, sharp critics, policy advocates - sober judges whose sovereignty is secured by the formal conventions of positivist research, established theory, institutional authority and/or disciplinary knowledge. This paper asks what happens when pleasure is allowed to emerge as a constitutive element in the relations of drug and alcohol research. What happens when we conceive our work as thinking with pleasure, rather than simply researching pleasure or thinking about it? I return to the later work of Foucault, reading it alongside conceptions of the experiment drawn from Science and Technology Studies, arguing that both the pleasures of drug consumption and drug research might be conceived more generatively as mutually implicated in events.

'Enjoying the kick': Locating pleasure within the drug consumption room.

BACKGROUND: Harm reduction policy and praxis has long struggled to accommodate the pleasures of alcohol and other drug use. Whilst scholars have consistently highlighted this struggle, how pleasure might come to practically inform the design and delivery of harm reduction policies and programs remains less clear. The present paper seeks to move beyond conceptual critiques of harm reduction's 'pleasure oversight' to more focused empirical analysis of how flows of pleasure emerge, circulate and, importantly, may be reoriented in the course of harm reduction practice. METHODS: We ground our analysis in the context of detailed ethnographic research in a drug consumption room in Frankfurt, Germany. Drawing on recent strands of post-humanist thought, the paper deploys the concept of the 'consumption event' to uncover the manner in which these facilities mediate the practice and embodied experience of drug use and incite or limit bodily potentials for intoxication and pleasure. RESULTS: Through the analysis, we mapped a diversity of pleasures as they emerged and circulated through events of consumption at the consumption room. Beyond the pleasurable intensities of intoxication's kick, these pleasures were expressed in a range of novel capacities, practices and drug using bodies. In each instance, pleasure could not be reduced to a simple, linear product of drug use. Rather, it arose for our participants through distinctive social and affective transformations enabled through events of consumption at the consumption room and the generative force of actors and associations of which these events were composed. CONCLUSION: Our research suggests that the drug consumption room serves as a conduit through which its clients can potentially enact more pleasurable, productive and positive relations to both themselves and their drug use. Acknowledging the centrality of pleasure to client engagement with these facilities, the paper concludes by drawing out the implications of these findings for the design and delivery of consumption room services.

Desiring assemblages: A case for desire over pleasure in critical drug studies.

While critical drug researchers have long pushed for an acknowledgement of pleasure in discourses of drug use, few have explored the alternative possibilities offered by Deleuze and Guattari's concept of desire. In this paper I map out some of the conceptual differences between pleasure and desire and explore the opportunities opened up by attending more closely to desire in critical drug studies. I suggest that while discourses of pleasure do make an important intervention into and against dominant narratives of risk, harm, and addiction, they may inadvertently be working to keep in place the very binaries and forms of neoliberal western subjectivity that support those narratives. I argue that a Deleuzo-Guattarian ontology of desire is a better tool with which to make sense of the complex relations that form between drugs and bodies, challenge medical and criminal responses to drug use, and bring forth assemblages that enhance, rather than diminish, bodily capacities.

Conceiving of addicted pleasures: A 'modern' paradox.

Drawing on research with people who inject drugs in London, UK, this article will explore how participants conceived of pleasure, and try to understand some of the tensions that ensued. There is a strong sense in participants' accounts that drug use is at points pleasurable but it should not, or rather, could not be conceived of in this way. As such, the article will reflect on several situations in which pleasure came up during fieldwork but was quickly redirected towards addiction using terms such as 'denial'. Trying to make sense of this seemingly paradoxical dynamic, in which pleasure can be addictive, but addiction cannot be pleasurable, I turn to some of the practices that actively keep pleasure and addiction apart, indeed, in some areas of the addiction sciences, antithetical. That is, a singular account of pleasure is produced as freely chosen (of the 'free' subject) in opposition to the determined nature of addiction (of the automated brain or object). These realities materialise in participants' accounts, but due to their constructed nature they also collapse and multiply. This 'hybridisation' is what Bruno Latour refers to as the paradox of the Moderns. Considering pleasure, however, as both natural and cultural, it is better conceived of as always in tension, expressed by participants as 'mixed feelings', 'love/hate', 'sweet and sour', 'good things and bad things'. Against a backdrop of neglect, especially within the context of injecting drug use, such conceptualisation can help acknowledge pleasure where it is least conceivable and yet perhaps has the most to offer.

The pleasures of drunken one-night stands: Assemblage theory and narrative environments.

BACKGROUND: In this study, we use assemblage theory to investigate the link between alcohol use and one-night stands. METHODS: The data come from qualitative interviews conducted with 104 young participants in the night-time economy. RESULTS: We show that: (i) alcohol-fuelled sexual explorations (e.g. erotic fantasizing, flirting and sex) are of paramount importance for young partygoers; (ii) sexualized territories (e.g. private parties, rural feasts and the backseat of cars) significantly shape the experience and performance of one-night stands; and (iii) contrary to previous research, one-night stands are to a large degree associated with pleasure-the immediate pleasure of having sex and the long-term pleasure of telling about it to others. CONCLUSION: We argue that drunken one-night stands are part and parcel of a drinking culture that places high value on sexual encounters and personal sex stories.

Psychedelic pleasures: An affective understanding of the joys of tripping.

BACKGROUND: This paper considers the pleasures of psychedelic drugs and proposes a Deleuzian understanding of drugged pleasures as affects. In spite of a large body of work on psychedelics, not least on their therapeutic potentials, the literature is almost completely devoid of discussions of the recreational practices and pleasures of entheogenic drugs. Yet, most people do not use psychedelics because of their curative powers, but because they are fun and enjoyable ways to alter the experience of reality. METHODS: In the analytical part of the paper, I examine 100 trip reports from an internet forum in order to explore the pleasures of tripping. RESULTS: The analyses map out how drugs such as LSD and mushrooms - in combination with contextual factors such as other people, music and nature - give rise to a set of affective modifications of the drug user's capacities to feel, sense and act. CONCLUSION: In conclusion it is argued that taking seriously the large group of recreational users of hallucinogens is important not only because it broadens our understanding of how entheogenic drugs work in different bodies and settings, but also because it may enable a more productive and harm reductive transmission of knowledge between the scientific and recreational psychedelic communities.