WorldWideScience

Sample records for hidden food rewards

  1. The Hidden Costs of Rewards.

    Science.gov (United States)

    Deci, Edward L.

    1976-01-01

    This paper discusses ways managers can motivate their employees to work and at the same time to increase their performance. Two theories of motivation--Vroom's theory and Atkinson's theory--focus on the use of extrinsic and intrinsic rewards respectively. A managerial strategy that combines the best of both intrinsic and extrinsic approaches to…

  2. Dopamine reward prediction errors reflect hidden state inference across time

    Science.gov (United States)

    Starkweather, Clara Kwon; Babayan, Benedicte M.; Uchida, Naoshige; Gershman, Samuel J.

    2017-01-01

    Midbrain dopamine neurons signal reward prediction error (RPE), or actual minus expected reward. The temporal difference (TD) learning model has been a cornerstone in understanding how dopamine RPEs could drive associative learning. Classically, TD learning imparts value to features that serially track elapsed time relative to observable stimuli. In the real world, however, sensory stimuli provide ambiguous information about the hidden state of the environment, leading to the proposal that TD learning might instead compute a value signal based on an inferred distribution of hidden states (a ‘belief state’). In this work, we asked whether dopaminergic signaling supports a TD learning framework that operates over hidden states. We found that dopamine signaling exhibited a striking difference between two tasks that differed only with respect to whether reward was delivered deterministically. Our results favor an associative learning rule that combines cached values with hidden state inference. PMID:28263301

  3. Reward sensitivity and food addiction in women.

    Science.gov (United States)

    Loxton, Natalie J; Tipman, Renée J

    2017-08-01

    Sensitivity to the rewarding properties of appetitive substances has long been implicated in excessive consumption of palatable foods and drugs of abuse. Previous research focusing on individual differences in reward responsiveness has found heightened trait reward sensitivity to be associated with binge-eating, hazardous drinking, and illicit substance use. Food addiction has been proposed as an extreme form of compulsive-overeating and has been associated with genetic markers of heightened reward responsiveness. However, little research has explicitly examined the association between reward sensitivity and food addiction. Further, the processes by which individual differences in this trait are associated with excessive over-consumption has not been determined. A total of 374 women from the community completed an online questionnaire assessing reward sensitivity, food addiction, emotional, externally-driven, and hedonic eating. High reward sensitivity was significantly associated with greater food addiction symptoms (r = 0.31). Bootstrapped tests of indirect effects found the relationship between reward sensitivity and food addiction symptom count to be uniquely mediated by binge-eating, emotional eating, and hedonic eating (notably, food availability). These indirect effects held even when controlling for BMI, anxiety, depression, and trait impulsivity. This study further supports the argument that high levels of reward sensitivity may offer a trait marker of vulnerability to excessive over-eating, beyond negative affect and impulse-control deficits. That the hedonic properties of food (especially food availability), emotional, and binge-eating behavior act as unique mediators suggest that interventions for reward-sensitive women presenting with food addiction may benefit from targeting food availability in addition to management of negative affect. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Associations between sleep parameters and food reward.

    Science.gov (United States)

    McNeil, Jessica; Cadieux, Sébastien; Finlayson, Graham; Blundell, John E; Doucet, Éric

    2015-06-01

    This study examined the effects of acute, isocaloric aerobic and resistance exercise on different sleep parameters, and whether changes in these sleep parameters between sessions were related to next morning food reward. Fourteen men and women (age: 21.9 ± 2.7 years; body mass index: 22.7 ± 1.9 kg m(-) ²) participated in three randomized crossover sessions: aerobic exercise; resistance exercise; and sedentary control. Target exercise energy expenditure was matched at 4 kcal kg(-1) of body weight, and performed at 70% of VO2peak or 70% of 1 repetition-maximal. Sleep was measured (accelerometry) for 22 h following each session. The 'wanting' for visual food cues (validated computer task) was assessed the next morning. There were no differences in sleep parameters and food 'wanting' between conditions. Decreases in sleep duration and earlier wake-times were significantly associated with increased food 'wanting' between sessions (P = 0.001). However, these associations were no longer significant after controlling for elapsed time between wake-time and the food reward task. These findings suggest that shorter sleep durations and earlier wake-times are associated with increased food reward, but these associations are driven by elapsed time between awakening and completion of the food reward task. © 2015 European Sleep Research Society.

  5. Inhibiting food reward: delay discounting, food reward sensitivity, and palatable food intake in overweight and obese women.

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    Appelhans, Bradley M; Woolf, Kathleen; Pagoto, Sherry L; Schneider, Kristin L; Whited, Matthew C; Liebman, Rebecca

    2011-11-01

    Overeating is believed to result when the appetitive motivation to consume palatable food exceeds an individual's capacity for inhibitory control of eating. This hypothesis was supported in recent studies involving predominantly normal weight women, but has not been tested in obese populations. The current study tested the interaction between food reward sensitivity and inhibitory control in predicting palatable food intake among energy-replete overweight and obese women (N = 62). Sensitivity to palatable food reward was measured with the Power of Food Scale. Inhibitory control was assessed with a computerized choice task that captures the tendency to discount large delayed rewards relative to smaller immediate rewards. Participants completed an eating in the absence of hunger protocol in which homeostatic energy needs were eliminated with a bland preload of plain oatmeal, followed by a bogus laboratory taste test of palatable and bland snacks. The interaction between food reward sensitivity and inhibitory control was a significant predictor of palatable food intake in regression analyses controlling for BMI and the amount of preload consumed. Probing this interaction indicated that higher food reward sensitivity predicted greater palatable food intake at low levels of inhibitory control, but was not associated with intake at high levels of inhibitory control. As expected, no associations were found in a similar regression analysis predicting intake of bland foods. Findings support a neurobehavioral model of eating behavior in which sensitivity to palatable food reward drives overeating only when accompanied by insufficient inhibitory control. Strengthening inhibitory control could enhance weight management programs.

  6. Using food as a reward: An examination of parental reward practices.

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    Roberts, Lindsey; Marx, Jenna M; Musher-Eizenman, Dara R

    2018-01-01

    Eating patterns and taste preferences are often established early in life. Many studies have examined how parental feeding practices may affect children's outcomes, including food intake and preference. The current study focused on a common food parenting practice, using food as a reward, and used Latent Profile Analysis (LPA) to examine whether mothers (n = 376) and fathers (n = 117) of children ages 2.8 to 7.5 (M = 4.7; SD = 1.1) grouped into profiles (i.e., subgroups) based on how they use of food as a reward. The 4-class model was the best-fitting LPA model, with resulting classes based on both the frequency and type of reward used. Classes were: infrequent reward (33%), tangible reward (21%), food reward (27%), and frequent reward (19%). The current study also explored whether children's eating styles (emotional overeating, rood fussiness, food responsiveness, and satiety responsiveness) and parenting style (Authoritative, Authoritarian, and Permissive) varied by reward profile. Analyses of Variance (ANOVA) revealed that the four profiles differed significantly for all outcome variables except satiety responsiveness. It appears that the use of tangible and food-based rewards have important implications in food parenting. More research is needed to better understand how the different rewarding practices affect additional child outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Impaired associative learning with food rewards in obese women.

    Science.gov (United States)

    Zhang, Zhihao; Manson, Kirk F; Schiller, Daniela; Levy, Ifat

    2014-08-04

    Obesity is a major epidemic in many parts of the world. One of the main factors contributing to obesity is overconsumption of high-fat and high-calorie food, which is driven by the rewarding properties of these types of food. Previous studies have suggested that dysfunction in reward circuits may be associated with overeating and obesity. The nature of this dysfunction, however, is still unknown. Here, we demonstrate impairment in reward-based associative learning specific to food in obese women. Normal-weight and obese participants performed an appetitive reversal learning task in which they had to learn and modify cue-reward associations. To test whether any learning deficits were specific to food reward or were more general, we used a between-subject design in which half of the participants received food reward and the other half received money reward. Our results reveal a marked difference in associative learning between normal-weight and obese women when food was used as reward. Importantly, no learning deficits were observed with money reward. Multiple regression analyses also established a robust negative association between body mass index and learning performance in the food domain in female participants. Interestingly, such impairment was not observed in obese men. These findings suggest that obesity may be linked to impaired reward-based associative learning and that this impairment may be specific to the food domain. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Moderate alcohol consumption stimulates food intake and food reward of savoury foods

    NARCIS (Netherlands)

    Schrieks, I.C.; Stafleu, A.; Griffioen-Roose, S.; Graaf, C. de; Witkamp, R.F.; Boerrigter-Rijneveld, R.; Hendriks, H.F.J.

    2015-01-01

    The aim of this study was to investigate whether food reward plays a role in the stimulating effect of moderate alcohol consumption on subsequent food intake. In addition, we explored the role of oral and gut sensory pathways in alcohol's effect on food reward by modified sham feeding (MSF) or

  9. Moderate alcohol consumption stimulates food intake and food reward of savoury foods

    NARCIS (Netherlands)

    Schrieks, I.C.; Stafleu, Annette; Griffioen-Roose, Sanne; Graaf, de Kees; Witkamp, R.F.; Boerrigter-Rijneveld, Rianne; Hendriks, H.F.J.

    2015-01-01

    The aim of this study was to investigate whether food reward plays a role in the stimulating effect of moderate alcohol consumption on subsequent food intake. In addition, we explored the role of oral and gut sensory pathways in alcohol's effect on food reward by modified sham feeding (MSF) or

  10. Palatable food consumption in children: interplay between (food) reward motivation and the home food environment.

    Science.gov (United States)

    De Decker, Annelies; Verbeken, Sandra; Sioen, Isabelle; Van Lippevelde, Wendy; Braet, Caroline; Eiben, Gabriele; Pala, Valeria; Reisch, Lucia A; De Henauw, Stefaan

    2017-04-01

    To understand the importance of the home food environment on unhealthy food consumption in children high in reward sensitivity, this study tested the hypothesis that the home availability of unhealthy food moderates the effect of reward sensitivity on children's fast-food consumption frequency, exerted via food cue responsiveness. Children between 7.5 and 14 years (n = 174, 50.6% boys) reported on reward sensitivity and food cue responsiveness (by means of the subscale 'external eating'). Their height and weight were measured. Parents reported on their children's fast-food consumption frequency, food cue responsiveness (by means of the subscale 'food responsiveness'), and on the home availability of unhealthy foods. Two moderated mediation models were conducted, one with the parent- and one with the child-reported food cue responsiveness as mediator. Findings suggested that with a high home availability of unhealthy foods, (a) a higher fast-food consumption frequency was found in children high in reward sensitivity and (b) the relation between reward sensitivity and the fast-food consumption frequency was mediated by external eating. The findings point at the importance of the home food environment in children high in reward sensitivity. They suggest to limit the home availability of unhealthy foods. What is Known: • Reward sensitivity (RS) is positively associated with children's palatable food consumption • In adolescents, this effect is mediated by food cue responsiveness, which determines the strength of an individual's motivation to obtain food when perceiving food cues What is New: • Children high in RS may be more vulnerable to palatable food cues in their everyday food environment because of a higher food cue responsiveness • The home food environment may be an important determining factor of the palatable food consumption of these children.

  11. Food reward system: current perspectives and future research needs.

    Science.gov (United States)

    Alonso-Alonso, Miguel; Woods, Stephen C; Pelchat, Marcia; Grigson, Patricia Sue; Stice, Eric; Farooqi, Sadaf; Khoo, Chor San; Mattes, Richard D; Beauchamp, Gary K

    2015-05-01

    This article reviews current research and cross-disciplinary perspectives on the neuroscience of food reward in animals and humans, examines the scientific hypothesis of food addiction, discusses methodological and terminology challenges, and identifies knowledge gaps and future research needs. Topics addressed herein include the role of reward and hedonic aspects in the regulation of food intake, neuroanatomy and neurobiology of the reward system in animals and humans, responsivity of the brain reward system to palatable foods and drugs, translation of craving versus addiction, and cognitive control of food reward. The content is based on a workshop held in 2013 by the North American Branch of the International Life Sciences Institute. © The Author(s) 2015. Published by Oxford University Press on behalf of the International Life Sciences Institute.

  12. Reconsidering Food Reward, Brain Stimulation, and Dopamine: Incentives Act Forward.

    Science.gov (United States)

    Newquist, Gunnar; Gardner, R Allen

    2015-01-01

    In operant conditioning, rats pressing levers and pigeons pecking keys depend on contingent food reinforcement. Food reward agrees with Skinner's behaviorism, undergraduate textbooks, and folk psychology. However, nearly a century of experimental evidence shows, instead, that food in an operant conditioning chamber acts forward to evoke species-specific feeding behavior rather than backward to reinforce experimenter-defined responses. Furthermore, recent findings in neuroscience show consistently that intracranial stimulation to reward centers and dopamine release, the proposed reward molecule, also act forward to evoke inborn species-specific behavior. These results challenge longstanding views of hedonic learning and must be incorporated into contemporary learning theory.

  13. Moderate alcohol consumption stimulates food intake and food reward of savoury foods.

    Science.gov (United States)

    Schrieks, Ilse C; Stafleu, Annette; Griffioen-Roose, Sanne; de Graaf, Cees; Witkamp, Renger F; Boerrigter-Rijneveld, Rianne; Hendriks, Henk F J

    2015-06-01

    The aim of this study was to investigate whether food reward plays a role in the stimulating effect of moderate alcohol consumption on subsequent food intake. In addition, we explored the role of oral and gut sensory pathways in alcohol's effect on food reward by modified sham feeding (MSF) or consumption of a preload after alcohol intake.In a single-blind crossover design, 24 healthy men were randomly assigned to either consumption of vodka/orange juice (20 g alcohol) or orange juice only, followed by consumption of cake, MSF of cake or no cake. Food reward was evaluated by actual food intake measured by an ad libitum lunch 45 min after alcohol ingestion and by behavioural indices of wanting and liking of four food categories (high fat, low fat, sweet and savoury).Moderate alcohol consumption increased food intake during the ad libitum lunch by 11% (+338 kJ, P = 0.004). Alcohol specifically increased intake (+127 kJ, P foods. Moreover, moderate alcohol consumption increased implicit wanting for savoury (P = 0.013) and decreased implicit wanting for sweet (P = 0.017) before the meal. Explicit wanting of low-fat savoury foods only was higher after alcohol followed by no cake as compared to after alcohol followed by cake MSF (P = 0.009), but not as compared to alcohol followed by cake consumption (P = 0.082). Both cake MSF and cake consumption had no overall effect on behavioural indices of food reward.To conclude, moderate alcohol consumption increased subsequent food intake, specifically of high-fat savoury foods. This effect was related to the higher food reward experienced for savoury foods. The importance of oral and gut sensory signalling in alcohol's effect on food reward remains largely unclear. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Hidden linkages between urbanization and food systems.

    Science.gov (United States)

    Seto, Karen C; Ramankutty, Navin

    2016-05-20

    Global societies are becoming increasingly urban. This shift toward urban living is changing our relationship with food, including how we shop and what we buy, as well as ideas about sanitation and freshness. Achieving food security in an era of rapid urbanization will require considerably more understanding about how urban and food systems are intertwined. Here we discuss some potential understudied linkages that are ripe for further examination. Copyright © 2016, American Association for the Advancement of Science.

  15. Reward systems and food intake: role of opioids.

    Science.gov (United States)

    Gosnell, B A; Levine, A S

    2009-06-01

    Humans eat for many reasons, including the rewarding qualities of foods. A host of neurotransmitters have been shown to influence eating behavior and some of these appear to be involved in reward-induced eating. Endogenous opioid peptides and their receptors were first reported more than 30 years ago, and studies suggesting a role of opioids in the regulation of food intake date back nearly as far. Opioid agonists and antagonists have corresponding stimulatory and inhibitory effects on feeding. In addition to studies aimed at identifying the relevant receptor subtypes and sites of action within the brain, there has been a continuing interest in the role of opioids on diet/taste preferences, food reward, and the overlap of food reward with others types of reward. Data exist that suggest a role for opioids in the control of appetite for specific macronutrients, but there is also evidence for their role in the stimulation of intake based on already-existing diet or taste preferences and in controlling intake motivated by hedonics rather than by energy needs. Finally, various types of studies indicate an overlap between mechanisms mediating drug reward and palatable food reward. Preference or consumption of sweet substances often parallels the self-administration of several drugs of abuse, and under certain conditions, the termination of intermittent access to sweet substances produces symptoms that resemble those observed during opiate withdrawal. The overconsumption of readily available and highly palatable foods likely contributes to the growing rates of obesity worldwide. An understanding of the role of opioids in mediating food reward and promoting the overconsumption of palatable foods may provide insights into new approaches for preventing obesity.

  16. Sneaking a peek: pigeons use peripheral vision (not mirrors) to find hidden food.

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    Ünver, Emre; Garland, Alexis; Tabrik, Sepideh; Güntürkün, Onur

    2017-07-01

    A small number of species are capable of recognizing themselves in the mirror when tested with the mark-and-mirror test. This ability is often seen as evidence of self-recognition and possibly even self-awareness. Strangely, a number of species, for example monkeys, pigs and dogs, are unable to pass the mark test but can locate rewarding objects by using the reflective properties of a mirror. Thus, these species seem to understand how a visual reflection functions but cannot apply it to their own image. We tested this discrepancy in pigeons-a species that does not spontaneously pass the mark test. Indeed, we discovered that pigeons can successfully find a hidden food reward using only the reflection, suggesting that pigeons can also use and potentially understand the reflective properties of mirrors, even in the absence of self-recognition. However, tested under monocular conditions, the pigeons approached and attempted to walk through the mirror rather than approach the physical food, displaying similar behavior to patients with mirror agnosia. These findings clearly show that pigeons do not use the reflection of mirrors to locate reward, but actually see the food peripherally with their near-panoramic vision. A re-evaluation of our current understanding of mirror-mediated behavior might be necessary-especially taking more fully into account species differences in visual field. This study suggests that use of reflections in a mirrored surface as a tool may be less widespread than currently thought.

  17. Food reward from a behavioural and (neuro)physiological perspective

    NARCIS (Netherlands)

    Bruijn, Suzanne E.M.

    2017-01-01

    Food reward is an important driver of food intake and triggers consumption of foods for pleasure, so-called hedonic eating, even in the absence of any energy deficits. Hedonic eating can trigger overeating and may therefore lead to obesity. Given the rise in obesity rates and the health risks

  18. Food allergy in breastfeeding babies. Hidden allergens in human milk.

    Science.gov (United States)

    Martín-Muñoz, M F; Pineda, F; García Parrado, G; Guillén, D; Rivero, D; Belver, T; Quirce, S

    2016-07-01

    Food allergy is a rare disorder among breastfeeding babies. Our aim was to identify responsible allergens in human milk. We studied babies developing allergic symptoms at the time they were breastfeeding. Skin prick tests (SPT) were performed with breast milk and food allergens. Specific IgE was assessed and IgE Immunoblotting experiments with breast milk were carried out to identify food allergens. Clinical evolution was evaluated after a maternal free diet. Five babies had confirmed breast milk allergy. Peanut, white egg and/or cow's milk were demonstrated as the hidden responsible allergens. No baby returned to develop symptoms once mother started a free diet. Three of these babies showed tolerance to other food allergens identified in human milk. A maternal free diet should be recommended only if food allergy is confirmed in breastfed babies.

  19. Brain Stimulation Reward Supports More Consistent and Accurate Rodent Decision-Making than Food Reward.

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    McMurray, Matthew S; Conway, Sineadh M; Roitman, Jamie D

    2017-01-01

    Animal models of decision-making rely on an animal's motivation to decide and its ability to detect differences among various alternatives. Food reinforcement, although commonly used, is associated with problematic confounds, especially satiety. Here, we examined the use of brain stimulation reward (BSR) as an alternative reinforcer in rodent models of decision-making and compared it with the effectiveness of sugar pellets. The discriminability of various BSR frequencies was compared to differing numbers of sugar pellets in separate free-choice tasks. We found that BSR was more discriminable and motivated greater task engagement and more consistent preference for the larger reward. We then investigated whether rats prefer BSR of varying frequencies over sugar pellets. We found that animals showed either a clear preference for sugar reward or no preference between reward modalities, depending on the frequency of the BSR alternative and the size of the sugar reward. Overall, these results suggest that BSR is an effective reinforcer in rodent decision-making tasks, removing food-related confounds and resulting in more accurate, consistent, and reliable metrics of choice.

  20. Divergent circuitry underlying food reward and intake effects of ghrelin: dopaminergic VTA-accumbens projection mediates ghrelin's effect on food reward but not food intake.

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    Skibicka, Karolina P; Shirazi, Rozita H; Rabasa-Papio, Cristina; Alvarez-Crespo, Mayte; Neuber, Corinna; Vogel, Heike; Dickson, Suzanne L

    2013-10-01

    Obesity has reached global epidemic proportions and creating an urgent need to understand mechanisms underlying excessive and uncontrolled food intake. Ghrelin, the only known circulating orexigenic hormone, potently increases food reward behavior. The neurochemical circuitry that links ghrelin to the mesolimbic reward system and to the increased food reward behavior remains unclear. Here we examine whether VTA-NAc dopaminergic signaling is required for the effects of ghrelin on food reward and intake. In addition, we examine the possibility of endogenous ghrelin acting on the VTA-NAc dopamine neurons. A D1-like or a D2 receptor antagonist was injected into the NAc in combination with ghrelin microinjection into the VTA to investigate whether this blockade attenuates ghrelin-induced food reward behavior. VTA injections of ghrelin produced a significant increase in food motivation/reward behavior, as measured by sucrose-induced progressive ratio operant conditioning, and chow intake. Pretreatment with either a D1-like or D2 receptor antagonist into the NAc, completely blocked the reward effect of ghrelin, leaving chow intake intact. We also found that this circuit is potentially relevant for the effects of endogenously released ghrelin as both antagonists reduced fasting (a state of high circulating levels of ghrelin) elevated sucrose-motivated behavior but not chow hyperphagia. Taken together our data identify the VTA to NAc dopaminergic projections, along with D1-like and D2 receptors in the NAc, as essential elements of the ghrelin responsive circuits controlling food reward behavior. Interestingly results also suggest that food reward behavior and simple intake of chow are controlled by divergent circuitry, where NAc dopamine plays an important role in food reward but not in food intake. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. The endocannabinoid system and appetite: relevance for food reward.

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    Jager, Gerry; Witkamp, Renger F

    2014-06-01

    Mounting evidence substantiates the central role of the endocannabinoid system (ECS) in the modulation of both homeostatic and hedonic elements of appetite and food intake. Conversely, feeding status and dietary patterns directly influence activity of the ECS. Following a general introduction on the functioning of the ECS, the present review specifically addresses its role in the modulation of hedonic eating. Humans possess strong motivational systems triggered by rewarding aspects of food. Food reward is comprised of two components: one appetitive (orienting towards food); the other consummatory (hedonic evaluation), also referred to as 'wanting' and 'liking', respectively. Endocannabinoid tone seems to influence both the motivation to feed and the hedonic value of foods, probably by modifying palatability. Human physiology underlying hedonic eating is still not fully understood. A better understanding of the role of the ECS in the rewarding value of specific foods or diets could offer new possibilities to optimise the balance between energy and nutrient intake for different target groups. These groups include the obese and overweight, and potentially individuals suffering from malnutrition. Examples for the latter group are patients with disease-related anorexia, as well as the growing population of frail elderly suffering from persistent loss of food enjoyment and appetite resulting in malnutrition and involuntary weight loss. It has become clear that the psychobiology of food hedonics is extremely complex and the clinical failure of CB1 inverse agonists including rimonabant (Accomplia®) has shown that 'quick wins' in this field are unlikely.

  2. The central GLP-1: implications for food and drug reward

    Directory of Open Access Journals (Sweden)

    Karolina Patrycja Skibicka

    2013-10-01

    Full Text Available Glucagon-like-peptide-1 (GLP-1 and its long acting analogues comprise a novel class of type 2 diabetes (T2D treatment. What makes them unique among other T2D drugs is their concurrent ability to reduce food intake, a great benefit considering the frequent comorbidity of T2D and obesity. The precise neural site of action underlying this beneficial effect is vigorously researched. In accordance with the classical model of food intake control GLP-1 action on feeding has been primarily ascribed to receptor populations in the hypothalamus and the hindbrain. In contrast to this common view, relevant GLP-1 receptor populations are distributed more widely, with a prominent mesolimbic complement emerging. The physiological relevance of the mesolimbic GLP-1 is suggested by the demonstration that similar anorexic effects can be obtained by independent stimulation of the mesolimbic and hypothalamic GLP-1 receptors. Results reviewed here support the idea that mesolimbic GLP-1 receptors are sufficient to reduce hunger-driven feeding, the hedonic value of food and food-motivation. In parallel, emerging evidence suggests that the range of action of GLP-1 on reward behavior is not limited to food-derived reward but extends to cocaine, amphetamine and alcohol reward. The new discoveries concerning GLP-1 action on the mesolimbic reward system significantly extend the potential therapeutic range of this drug target.

  3. Ghrelin and food reward: the story of potential underlying substrates.

    Science.gov (United States)

    Skibicka, Karolina P; Dickson, Suzanne L

    2011-11-01

    The incidence of obesity is increasing at an alarming rate and this worldwide epidemic represents a significant decrease in life span and quality of life of a large part of the affected population. Therefore an understanding of mechanisms underlying food overconsumption and obesity development is urgent and essential to find potential treatments. Research investigating mechanisms underlying obesity and the control of food intake has recently experienced a major shift in focus, from the brain's hypothalamus to additional important neural circuits controlling emotion, cognition and motivated behavior. Among them, the mesolimbic system, and the changes in reward and motivated behavior for food, emerge as new promising treatment targets. Furthermore, there is also growing appreciation of the impact of peripheral hormones that signal nutrition status to the mesolimbic areas, and especially the only known circulating orexigenic hormone, ghrelin. This review article provides a synthesis of recent evidence concerning the impact of manipulation of ghrelin and its receptor on models of food reward/food motivation behavior and the mesolimbic circuitry. Particular attention is given to the potential neurocircuitry and neurotransmitter systems downstream of ghrelin's effects on food reward. Copyright © 2011. Published by Elsevier Inc.

  4. Spatial discounting of food and social rewards in guppies (Poecilia reticulata

    Directory of Open Access Journals (Sweden)

    Nelly eMühlhoff

    2011-04-01

    Full Text Available In temporal discounting, animals trade off the time to obtain a reward against the quality of a reward, choosing between a smaller reward available sooner versus a larger reward available later. Similar discounting can apply over space, when animals choose between smaller and closer versus larger and more distant rewards. Most studies of temporal and spatial discounting in nonhuman animals use food as the reward, and it is not established whether animals trade off other preferred stimuli in similar ways. Here, we offered female guppies (Poecilia reticulata a spatial discounting task in which we measured preferences for a larger reward as the distance to it increased relative to a closer but smaller reward. We tested whether the fish discounted reward types differently by offering subjects either food items or same-sex conspecifics as rewards. Before beginning the discounting tasks, we conducted validation tests to ensure that subjects equally valued the food and social stimuli in the quantities provided. In the discounting task, subjects switched their preferences from the larger to the smaller reward as the distance to the larger reward increased (spatial discounting, but the pattern and magnitude of discounting did not differ across the two reward types. These findings indicate that guppies show similar patterns of discounting food and social rewards in a spatial task. In an analysis of travel times, however, the fish swam faster to food rewards than to shoaling partners. This difference in travel times implies that fish temporally discounted social rewards less steeply than food rewards. Thus, reward type influences temporal discounting, suggesting a dissociation between temporal and spatial discounting. Our results illustrate how animals adjust choices and travel times depending on both the type of cost (time, distance and benefits (food, social partners.

  5. Facilitating or undermining? The effect of reward on food acceptance. A narrative review.

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    Cooke, Lucy J; Chambers, Lucy C; Añez, Elizabeth V; Wardle, Jane

    2011-10-01

    Using rewards in child feeding is commonplace and viewed as effective by parents, although some express concern about using 'bribery'. Psychological and economic theorists emphasize the beneficial effects of rewards in enhancing performance, although, there is evidence that the offer of rewards undermines intrinsic motivation and decreases enjoyment of the rewarded task. In the food domain, results have been mixed, but this may be explained, at least partly in terms of the measured outcome (liking vs intake) and the initial level of motivation towards the target foods (liked vs disliked). Where intake is the outcome, rewards have had broadly positive effects, but when it is liking, rewards can have negative effects if the target food is already liked. Another issue concerns the type of reward offered. While offering food as a reward appear to be universally negative, there is evidence to suggest that non-food tangible rewards (e.g., stickers), or non-tangible rewards (praise) can be highly effective in encouraging children to taste new or less liked foods sufficiently often to benefit from the 'mere exposure' effect. We suggest that the judicious use of rewards may facilitate children's acceptance of healthy foods. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Fasting for 24 hours heightens reward from food and food-related cues.

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    Cameron, Jameason D; Goldfield, Gary S; Finlayson, Graham; Blundell, John E; Doucet, Eric

    2014-01-01

    We examined the impact of a 24 hour complete fast (vs. fed state) on two measures of food reward: 1) 'wanting', as measured by response to food images and by the relative-reinforcing value of food (RRV), and 2) 'liking', as measured by response to food images and the hedonic evaluation of foods consumed. Utilizing a randomized crossover design, 15 subjects (9 male; 6 female) aged 28.6±4.5 yrs with body mass index 25.3±1.4 kg/m(2) were randomized and counterbalanced to normal feeding (FED) and 24-hour fast (FASTED) conditions. Trait characteristics were measured with the Three Factor Eating Questionnaire. Two computer tasks measured food reward: 1) RRV progressive ratio task, 2) explicit 'liking' and 'wanting' (Leeds Food Preference Questionnaire, LFPQ). Also measured were ad libitum energy intake (EI; buffet) and food 'liking' (visual analogue scale) of personalized stimuli. There were no significant anthropometric changes between conditions. Appetite scores, hedonic ratings of 'liking', and ad libitum EI all significantly increased under the FASTED condition (pFASTED condition there were significant increases in the RRV of snack foods; similarly, explicit 'wanting' and 'liking' significantly increased for all food categories. 'Liking' of sweet foods remained high across-meals under FASTED, but savory foods decreased in hedonic saliency. Relative to a fed state, we observed an increase in hedonic ratings of food, the rewarding value of food, and food intake after a 24 hr fast. Alliesthesia to food and food cues is suggested by heightened hedonic ratings under the FASTED condition relative to FED.

  7. Rewards.

    Science.gov (United States)

    Gunderman, Richard B; Kamer, Aaron P

    2011-05-01

    For much of the 20th century, psychologists and economists operated on the assumption that work is devoid of intrinsic rewards, and the only way to get people to work harder is through the use of rewards and punishments. This so-called carrot-and-stick model of workplace motivation, when applied to medical practice, emphasizes the use of financial incentives and disincentives to manipulate behavior. More recently, however, it has become apparent that, particularly when applied to certain kinds of work, such approaches can be ineffective or even frankly counterproductive. Instead of focusing on extrinsic rewards such as compensation, organizations and their leaders need to devote more attention to the intrinsic rewards of work itself. This article reviews this new understanding of rewards and traces out its practical implications for radiology today. Copyright © 2011. Published by Elsevier Inc.

  8. Exploring food reward and calorie intake in self-perceived food addicts.

    Science.gov (United States)

    Ruddock, Helen K; Field, Matt; Hardman, Charlotte A

    2017-08-01

    Previous research indicates that many people perceive themselves to be addicted to food. These 'self-perceived food addicts' may demonstrate aberrant eating patterns which put them at greater risk of overeating. However this is yet to be empirically investigated. The current study investigated whether self-perceived food addicts would exhibit higher food reward and calorie intake in a laboratory context relative to self-perceived non-addicts. A secondary aim was to investigate whether self-perceived food addicts would demonstrate increased food liking and/or increased hunger ratings. Finally, we explored whether self-perceived food addicts demonstrate patterns of aberrant eating, beyond that predicted by measures of trait dietary disinhibition and restraint. Female participants (self-perceived food addicts n = 31, non-addicts n = 29) completed measures of hunger, food reward (desire-to-eat, willingness-to-pay ratings, and an operant response task) and liking for high- and low-fat foods. Participants completed all measures when they were hungry, and again when they were satiated after consuming a fixed-lunch meal. Finally, participants were provided with ad-libitum access to high-and low-fat foods. Results indicated that self-perceived food addicts consumed more calories from high-fat food compared to non-addicts, despite the absence of any between-group differences in hunger or overall liking ratings. Self-perceived food addicts also displayed higher desire-to-eat ratings across foods compared to non-addicts, but groups did not differ on other measures of food reward. However, the differences in calorie intake and desire-to-eat between self-perceived food addicts and non-addicts were no longer significant after controlling for dietary disinhibition and restraint. These findings suggest that self-perceived food addicts experience food as more rewarding and have a tendency to overeat. However, this may be attributable to increased dietary disinhibition and

  9. Integration of homeostatic signaling and food reward processing in the human brain.

    Science.gov (United States)

    Simon, Joe J; Wetzel, Anne; Sinno, Maria Hamze; Skunde, Mandy; Bendszus, Martin; Preissl, Hubert; Enck, Paul; Herzog, Wolfgang; Friederich, Hans-Christoph

    2017-08-03

    Food intake is guided by homeostatic needs and by the reward value of food, yet the exact relation between the two remains unclear. The aim of this study was to investigate the influence of different metabolic states and hormonal satiety signaling on responses in neural reward networks. Twenty-three healthy participants underwent functional magnetic resonance imaging while performing a task distinguishing between the anticipation and the receipt of either food- or monetary-related reward. Every participant was scanned twice in a counterbalanced fashion, both during a fasted state (after 24 hours fasting) and satiety. A functional connectivity analysis was performed to investigate the influence of satiety signaling on activation in neural reward networks. Blood samples were collected to assess hormonal satiety signaling. Fasting was associated with sensitization of the striatal reward system to the anticipation of food reward irrespective of reward magnitude. Furthermore, during satiety, individual ghrelin levels were associated with increased neural processing during the expectation of food-related reward. Our findings show that physiological hunger stimulates food consumption by specifically increasing neural processing during the expectation (i.e., incentive salience) but not the receipt of food-related reward. In addition, these findings suggest that ghrelin signaling influences hedonic-driven food intake by increasing neural reactivity during the expectation of food-related reward. These results provide insights into the neurobiological underpinnings of motivational processing and hedonic evaluation of food reward. ClinicalTrials.gov NCT03081585. This work was supported by the German Competence Network on Obesity, which is funded by the German Federal Ministry of Education and Research (FKZ 01GI1122E).

  10. Galanin-Expressing GABA Neurons in the Lateral Hypothalamus Modulate Food Reward and Noncompulsive Locomotion

    OpenAIRE

    Qualls-Creekmore, Emily; Yu, Sangho; Francois, Marie; Hoang, John; Huesing, Clara; Bruce-Keller, Annadora; Burk, David; Berthoud, Hans-Rudolf; Morrison, Christopher D.; Münzberg, Heike

    2017-01-01

    The lateral hypothalamus (LHA) integrates reward and appetitive behavior and is composed of many overlapping neuronal populations. Recent studies associated LHA GABAergic neurons (LHAGABA), which densely innervate the ventral tegmental area (VTA), with modulation of food reward and consumption; yet, LHAGABA projections to the VTA exclusively modulated food consumption, not reward. We identified a subpopulation of LHAGABA neurons that coexpress the neuropeptide galanin (LHAGal). These LHAGal n...

  11. Brain reward responses to food stimuli among female monozygotic twins discordant for BMI

    NARCIS (Netherlands)

    Doornweerd, Stieneke; De Geus, Eco J; Barkhof, Frederik; van Bloemendaal, Liselotte; Boomsma, Dorret I; van Dongen, J.; Drent, Madeleine L; Willemsen, Gonneke; Veltman, Dick J; IJzerman, Richard G

    2017-01-01

    Obese individuals are characterized by altered brain reward responses to food. Despite the latest discovery of obesity-associated genes, the contribution of environmental and genetic factors to brain reward responsiveness to food remains largely unclear. Sixteen female monozygotic twin pairs with a

  12. Brain reward responses to food stimuli among female monozygotic twins discordant for BMI

    NARCIS (Netherlands)

    Doornweerd, Stieneke; De Geus, Eco J; Barkhof, Frederik; van Bloemendaal, Liselotte; Boomsma, Dorret I; van Dongen, J.; Drent, Madeleine L; Willemsen, Gonneke; Veltman, Dick J; IJzerman, Richard G

    2018-01-01

    Obese individuals are characterized by altered brain reward responses to food. Despite the latest discovery of obesity-associated genes, the contribution of environmental and genetic factors to brain reward responsiveness to food remains largely unclear. Sixteen female monozygotic twin pairs with a

  13. The role of the central ghrelin system in reward from food and chemical drugs.

    Science.gov (United States)

    Dickson, Suzanne L; Egecioglu, Emil; Landgren, Sara; Skibicka, Karolina P; Engel, Jörgen A; Jerlhag, Elisabet

    2011-06-20

    Here we review recent advances that identify a role for the central ghrelin signalling system in reward from both natural rewards (such as food) and artificial rewards (that include alcohol and drugs of abuse). Whereas ghrelin emerged as a stomach-derived hormone involved in energy balance, hunger and meal initiation via hypothalamic circuits, it now seems clear that it also has a role in motivated reward-driven behaviours via activation of the so-called "cholinergic-dopaminergic reward link". This reward link comprises a dopamine projection from the ventral tegmental area (VTA) to the nucleus accumbens together with a cholinergic input, arising primarily from the laterodorsal tegmental area. Ghrelin administration into the VTA or LDTg activates the "cholinergic-dopaminergic" reward link, suggesting that ghrelin may increase the incentive value of motivated behaviours such as reward-seeking behaviour ("wanting" or "incentive motivation"). Further, direct injection of ghrelin into the brain ventricles or into the VTA increases the consumption of rewarding foods as well as alcohol in mice and rats. Studies in rodents show beneficial effects of ghrelin receptor (GHS-R1A) antagonists to suppress the intake of palatable food, to reduce preference for caloric foods, to suppress food reward and motivated behaviour for food. They have also been shown to reduce alcohol consumption, suppress reward induced by alcohol, cocaine and amphetamine. Furthermore, variations in the GHS-R1A and pro-ghrelin genes have been associated with high alcohol consumption, smoking and increased weight gain in alcohol dependent individuals as well as with bulimia nervosa and obesity. Thus, the central ghrelin signalling system interfaces neurobiological circuits involved in reward from food as well as chemical drugs; agents that directly or indirectly suppress this system emerge as potential candidate drugs for suppressing problematic over-eating that leads to obesity as well as for the

  14. The role of food and nutrition system approaches in tackling hidden hunger.

    Science.gov (United States)

    Burchi, Francesco; Fanzo, Jessica; Frison, Emile

    2011-02-01

    One of the World's greatest challenges is to secure sufficient and healthy food for all, and to do so in an environmentally sustainable manner. This review explores the interrelationships of food, health, and environment, and their role in addressing chronic micronutrient deficiencies, also known as "hidden hunger", affecting over two billion people worldwide. While the complexity and underlying determinants of undernutrition have been well-understood for decades, the scaling of food and nutrition system approaches that combine sustainable agriculture aimed at improved diet diversity and livelihoods have been limited in their development and implementation. However, an integrated system approach to reduce hidden hunger could potentially serve as a sustainable opportunity.

  15. Junk food advertising moderates the indirect effect of reward sensitivity and food consumption via the urge to eat.

    Science.gov (United States)

    Kidd, Chloe; Loxton, Natalie J

    2018-05-01

    The current study aimed to identify how underlying individual differences increases vulnerability to television food advertising. In particular, this study examined how reward sensitivity, a biologically-based predisposition to approach rewards (such as appetitive foods) in the environment, influenced participants' vulnerability to television food advertising and subsequent food consumption. Ninety-eight participants were randomly assigned to a cue condition (food cues versus non-food cues) and then viewed a 30 min documentary interrupted by advertising featuring a mix of food and neutral advertising (food cue condition) or only neutral advertising (non-food cue condition). Participants' reward sensitivity, approach motivation measured as urge to eat, and food consumption were recorded. Moderated mediation regression analyses revealed the positive association between reward sensitivity and food consumption was mediated by an increase in urge to eat, but only when participants were exposed to food advertising. These findings suggest heightened reward sensitivity, exposure to appetitive food cues, and approach motivation are key interacting mechanisms that may lead to maladaptive eating behaviours. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Where is the comfort in comfort foods? Mechanisms linking fat signaling, reward, and emotion.

    Science.gov (United States)

    Weltens, N; Zhao, D; Van Oudenhove, L

    2014-03-01

    Food in general, and fatty foods in particular, have obtained intrinsic reward value throughout evolution. This reward value results from an interaction between exteroceptive signals from different sensory modalities, interoceptive hunger/satiety signals from the gastrointestinal tract to the brain, as well as ongoing affective and cognitive processes. Further evidence linking food to emotions stems from folk psychology ('comfort foods') and epidemiological studies demonstrating high comorbidity rates between disorders of food intake, including obesity, and mood disorders such as depression. This review paper aims to give an overview of current knowledge on the neurophysiological mechanisms underlying the link between (fatty) foods, their reward value, and emotional responses to (anticipation of) their intake in humans. Firstly, the influence of exteroceptive sensory signals, including visual, olfactory ('anticipatory food reward'), and gustatory ('consummatory food reward'), on the encoding of reward value in the (ventral) striatum and of subjective pleasantness in the cingulate and orbitofrontal cortex will be discussed. Differences in these pathways and mechanisms between lean and obese subjects will be highlighted. Secondly, recent studies elucidating the mechanisms of purely interoceptive fatty acid-induced signaling from the gastrointestinal tract to the brain, including the role of gut peptides, will be presented. These studies have demonstrated that such subliminal interoceptive stimuli may impact on hedonic circuits in the brain, and thereby influence the subjective and neural responses to negative emotion induction. This suggests that the effect of foods on mood may even occur independently from their exteroceptive sensory properties. © 2014 John Wiley & Sons Ltd.

  17. Independent functional connectivity networks underpin food and monetary reward sensitivity in excess weight.

    Science.gov (United States)

    Verdejo-Román, Juan; Fornito, Alex; Soriano-Mas, Carles; Vilar-López, Raquel; Verdejo-García, Antonio

    2017-02-01

    Overvaluation of palatable food is a primary driver of obesity, and is associated with brain regions of the reward system. However, it remains unclear if this network is specialized in food reward, or generally involved in reward processing. We used functional magnetic resonance imaging (fMRI) to characterize functional connectivity during processing of food and monetary rewards. Thirty-nine adults with excess weight and 37 adults with normal weight performed the Willingness to Pay for Food task and the Monetary Incentive Delay task in the fMRI scanner. A data-driven graph approach was applied to compare whole-brain, task-related functional connectivity between groups. Excess weight was associated with decreased functional connectivity during the processing of food rewards in a network involving primarily frontal and striatal areas, and increased functional connectivity during the processing of monetary rewards in a network involving principally frontal and parietal areas. These two networks were topologically and anatomically distinct, and were independently associated with BMI. The processing of food and monetary rewards involve segregated neural networks, and both are altered in individuals with excess weight. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Adolescents' Views about a Proposed Rewards Intervention to Promote Healthy Food Choice in Secondary School Canteens

    Science.gov (United States)

    McEvoy, C. T.; Lawton, J.; Kee, F.; Young, I. S.; Woodside, J. V.; McBratney, J.; McKinley, M. C.

    2014-01-01

    Using rewards may be an effective method to positively influence adolescent eating behaviour, but evidence regarding this approach is limited. The aim of this study was to explore young adolescent views about a proposed reward intervention associated with food choice in school canteens. Focus groups were held in 10 schools located in lower…

  19. Brain reward system's alterations in response to food and monetary stimuli in overweight and obese individuals.

    Science.gov (United States)

    Verdejo-Román, Juan; Vilar-López, Raquel; Navas, Juan F; Soriano-Mas, Carles; Verdejo-García, Antonio

    2017-02-01

    The brain's reward system is crucial to understand obesity in modern society, as increased neural responsivity to reward can fuel the unhealthy food choices that are driving the growing obesity epidemic. Brain's reward system responsivity to food and monetary rewards in individuals with excessive weight (overweight and obese) versus normal weight controls, along with the relationship between this responsivity and body mass index (BMI) were tested. The sample comprised 21 adults with obesity (BMI > 30), 21 with overweight (BMI between 25 and 30), and 39 with normal weight (BMI food (Willing to Pay) and monetary rewards (Monetary Incentive Delay). Neural activations within the brain reward system were compared across the three groups. Curve fit analyses were conducted to establish the association between BMI and brain reward system's response. Individuals with obesity had greater food-evoked responsivity in the dorsal and ventral striatum compared with overweight and normal weight groups. There was an inverted U-shape association between BMI and monetary-evoked responsivity in the ventral striatum, medial frontal cortex, and amygdala; that is, individuals with BMIs between 27 and 32 had greater responsivity to monetary stimuli. Obesity is associated with greater food-evoked responsivity in the ventral and dorsal striatum, and overweight is associated with greater monetary-evoked responsivity in the ventral striatum, the amygdala, and the medial frontal cortex. Findings suggest differential reactivity of the brain's reward system to food versus monetary rewards in obesity and overweight. Hum Brain Mapp 38:666-677, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Impaired cross-talk between mesolimbic food reward processing and metabolic signaling predicts body mass index

    Directory of Open Access Journals (Sweden)

    Joe J Simon

    2014-10-01

    Full Text Available The anticipation of the pleasure derived from food intake drives the motivation to eat, and hence facilitate overconsumption of food which ultimately results in obesity. Brain imaging studies provide evidence that mesolimbic brain regions underlie both general as well as food related anticipatory reward processing. In light of this knowledge, the present study examined the neural responsiveness of the ventral striatum in participants with a broad BMI spectrum. The study differentiated between general (i.e. monetary and food related anticipatory reward processing. We recruited a sample of volunteers with greatly varying body weights, ranging from a low BMI (below 20 kg/m² over a normal (20 to 25 kg/m² and overweight (25 to 30 kg/m² BMI, to class I (30 to 35 kg/m² and class II (35 to 40 kg/m² obesity. A total of 24 participants underwent functional magnetic resonance imaging whilst performing both a food and monetary incentive delay task, which allows to measure neural activation during the anticipation of rewards. After the presentation of a cue indicating the amount of food or money to be won, participants had to react correctly in order to earn snack points or money coins which could then be exchanged for real food or money, respectively, at the end of the experiment. During the anticipation of both types of rewards, participants displayed activity in the ventral striatum, a region that plays a pivotal role in the anticipation of rewards. Additionally, we observed that specifically anticipatory food reward processing predicted the individual BMI (current and maximum lifetime. This relation was found to be mediated by impaired hormonal satiety signaling, i.e. increased leptin levels and insulin resistance. These findings suggest that heightened food reward motivation contributes to obesity through impaired metabolic signaling.

  1. Reward, dopamine and the control of food intake: implications for obesity

    Energy Technology Data Exchange (ETDEWEB)

    Volkow N. D.; Wang G.; Volkow, N.D.; Wang, G.-J.; Baler, R.D.

    2011-10-01

    The ability to resist the urge to eat requires the proper functioning of neuronal circuits involved in top-down control to oppose the conditioned responses that predict reward from eating the food and the desire to eat the food. Imaging studies show that obese subjects might have impairments in dopaminergic pathways that regulate neuronal systems associated with reward sensitivity, conditioning and control. It is known that the neuropeptides that regulate energy balance (homeostatic processes) through the hypothalamus also modulate the activity of dopamine cells and their projections into regions involved in the rewarding processes underlying food intake. It is postulated that this could also be a mechanism by which overeating and the resultant resistance to homoeostatic signals impairs the function of circuits involved in reward sensitivity, conditioning and cognitive control.

  2. Reward, dopamine and the control of food intake: implications for obesity

    International Nuclear Information System (INIS)

    Volkow, N.D.; Wang, G.J.; Baler, R.D.

    2011-01-01

    The ability to resist the urge to eat requires the proper functioning of neuronal circuits involved in top-down control to oppose the conditioned responses that predict reward from eating the food and the desire to eat the food. Imaging studies show that obese subjects might have impairments in dopaminergic pathways that regulate neuronal systems associated with reward sensitivity, conditioning and control. It is known that the neuropeptides that regulate energy balance (homeostatic processes) through the hypothalamus also modulate the activity of dopamine cells and their projections into regions involved in the rewarding processes underlying food intake. It is postulated that this could also be a mechanism by which overeating and the resultant resistance to homoeostatic signals impairs the function of circuits involved in reward sensitivity, conditioning and cognitive control.

  3. The Role of Food and Nutrition System Approaches in Tackling Hidden Hunger

    Directory of Open Access Journals (Sweden)

    Emile Frison

    2011-01-01

    Full Text Available One of the World’s greatest challenges is to secure sufficient and healthy food for all, and to do so in an environmentally sustainable manner. This review explores the interrelationships of food, health, and environment, and their role in addressing chronic micronutrient deficiencies, also known as “hidden hunger”, affecting over two billion people worldwide. While the complexity and underlying determinants of undernutrition have been well-understood for decades, the scaling of food and nutrition system approaches that combine sustainable agriculture aimed at improved diet diversity and livelihoods have been limited in their development and implementation. However, an integrated system approach to reduce hidden hunger could potentially serve as a sustainable opportunity.

  4. Modulation of Food Reward by Endocrine and Environmental Factors: Update and Perspective.

    Science.gov (United States)

    Figlewicz, Dianne P

    2015-01-01

    Palatable foods are frequently high in energy density. Chronic consumption of high-energy density foods can contribute to the development of cardiometabolic pathology including obesity, diabetes, and cardiovascular disease. This article reviews the contributions of extrinsic and intrinsic factors that influence the reward components of food intake. A narrative review was conducted to determine the behavioral and central nervous system (CNS) related processes involved in the reward components of high-energy density food intake. The rewarding aspects of food, particularly palatable and preferred foods, are regulated by CNS circuitry. Overlaying this regulation is modulation by intrinsic endocrine systems and metabolic hormones relating to energy homeostasis, developmental stage, or gender. It is now recognized that extrinsic or environmental factors, including ambient diet composition and the provocation of stress or anxiety, also contribute substantially to the expression of food reward behaviors such as motivation for, and seeking of, preferred foods. High-energy density food intake is influenced by both physiological and pathophysiological processes. Contextual, behavioral, and psychological factors and CNS-related processes represent potential targets for multiple types of therapeutic intervention.

  5. Value and probability coding in a feedback-based learning task utilizing food rewards.

    Science.gov (United States)

    Tricomi, Elizabeth; Lempert, Karolina M

    2015-01-01

    For the consequences of our actions to guide behavior, the brain must represent different types of outcome-related information. For example, an outcome can be construed as negative because an expected reward was not delivered or because an outcome of low value was delivered. Thus behavioral consequences can differ in terms of the information they provide about outcome probability and value. We investigated the role of the striatum in processing probability-based and value-based negative feedback by training participants to associate cues with food rewards and then employing a selective satiety procedure to devalue one food outcome. Using functional magnetic resonance imaging, we examined brain activity related to receipt of expected rewards, receipt of devalued outcomes, omission of expected rewards, omission of devalued outcomes, and expected omissions of an outcome. Nucleus accumbens activation was greater for rewarding outcomes than devalued outcomes, but activity in this region did not correlate with the probability of reward receipt. Activation of the right caudate and putamen, however, was largest in response to rewarding outcomes relative to expected omissions of reward. The dorsal striatum (caudate and putamen) at the time of feedback also showed a parametric increase correlating with the trialwise probability of reward receipt. Our results suggest that the ventral striatum is sensitive to the motivational relevance, or subjective value, of the outcome, while the dorsal striatum codes for a more complex signal that incorporates reward probability. Value and probability information may be integrated in the dorsal striatum, to facilitate action planning and allocation of effort. Copyright © 2015 the American Physiological Society.

  6. Response of neural reward regions to food cues in autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Cascio Carissa J

    2012-05-01

    Full Text Available Abstract Background One hypothesis for the social deficits that characterize autism spectrum disorders (ASD is diminished neural reward response to social interaction and attachment. Prior research using established monetary reward paradigms as a test of non-social reward to compare with social reward may involve confounds in the ability of individuals with ASD to utilize symbolic representation of money and the abstraction required to interpret monetary gains. Thus, a useful addition to our understanding of neural reward circuitry in ASD includes a characterization of the neural response to primary rewards. Method We asked 17 children with ASD and 18 children without ASD to abstain from eating for at least four hours before an MRI scan in which they viewed images of high-calorie foods. We assessed the neural reward network for increases in the blood oxygenation level dependent (BOLD signal in response to the food images Results We found very similar patterns of increased BOLD signal to these images in the two groups; both groups showed increased BOLD signal in the bilateral amygdala, as well as in the nucleus accumbens, orbitofrontal cortex, and insula. Direct group comparisons revealed that the ASD group showed a stronger response to food cues in bilateral insula along the anterior-posterior gradient and in the anterior cingulate cortex than the control group, whereas there were no neural reward regions that showed higher activation for controls than for ASD. Conclusion These results suggest that neural response to primary rewards is not diminished but in fact shows an aberrant enhancement in children with ASD.

  7. Hormonal and neural mechanisms of food reward, eating behaviour and obesity.

    Science.gov (United States)

    Murray, Susan; Tulloch, Alastair; Gold, Mark S; Avena, Nicole M

    2014-09-01

    With rising rates of obesity, research continues to explore the contributions of homeostatic and hedonic mechanisms related to eating behaviour. In this Review, we synthesize the existing information on select biological mechanisms associated with reward-related food intake, dealing primarily with consumption of highly palatable foods. In addition to their established functions in normal feeding, three primary peripheral hormones (leptin, ghrelin and insulin) play important parts in food reward. Studies in laboratory animals and humans also show relationships between hyperphagia or obesity and neural pathways involved in reward. These findings have prompted questions regarding the possibility of addictive-like aspects in food consumption. Further exploration of this topic may help to explain aberrant eating patterns, such as binge eating, and provide insight into the current rates of overweight and obesity.

  8. Ghrelin interacts with neuropeptide Y Y1 and opioid receptors to increase food reward.

    Science.gov (United States)

    Skibicka, Karolina P; Shirazi, Rozita H; Hansson, Caroline; Dickson, Suzanne L

    2012-03-01

    Ghrelin, a stomach-derived hormone, is an orexigenic peptide that was recently shown to potently increase food reward behavior. The neurochemical circuitry that links ghrelin to the mesolimbic system and food reward behavior remains unclear. Here we examined the contribution of neuropeptide Y (NPY) and opioids to ghrelin's effects on food motivation and intake. Both systems have well-established links to the mesolimbic ventral tegmental area (VTA) and reward/motivation control. NPY mediates the effect of ghrelin on food intake via activation of NPY-Y1 receptor (NPY-Y1R); their connection with respect to motivated behavior is unexplored. The role of opioids in any aspect of ghrelin's action on food-oriented behaviors is unknown. Rats were trained in a progressive ratio sucrose-induced operant schedule to measure food reward/motivation behavior. Chow intake was measured immediately after the operant test. In separate experiments, we explored the suppressive effects of a selective NPY-Y1R antagonist or opioid receptor antagonist naltrexone, injected either intracerebroventricularly or intra-VTA, on ghrelin-induced food reward behavior. The ventricular ghrelin-induced increase in sucrose-motivated behavior and chow intake were completely blocked by intracerebroventricular pretreatment with either an NPY-Y1R antagonist or naltrexone. The intra-VTA ghrelin-induced sucrose-motivated behavior was blocked only by intra-VTA naltrexone. In contrast, the intra-VTA ghrelin-stimulated chow intake was attenuated only by intra-VTA NPY-Y1 blockade. Finally, ghrelin infusion was associated with an elevated VTA μ-opioid receptor expression. Thus, we identify central NPY and opioid signaling as the necessary mediators of food intake and reward effects of ghrelin and localize these interactions to the mesolimbic VTA.

  9. Cortical GluN2B deletion attenuates punished suppression of food reward-seeking.

    Science.gov (United States)

    Radke, Anna K; Nakazawa, Kazu; Holmes, Andrew

    2015-10-01

    Compulsive behavior, which is a hallmark of psychiatric disorders such as addiction and obsessive-compulsive disorder, engages corticostriatal circuits. Previous studies indicate a role for corticostriatal N-methyl-D-aspartate receptors (NMDARs) in mediating compulsive-like responding for drugs of abuse, but the specific receptor subunits controlling reward-seeking in the face of punishment remain unclear. The current study assessed the involvement of corticostriatal GluN2B-containing NMDARs in measures of persistent and punished food reward-seeking. Mice with genetic deletion of GluN2B in one of three distinct neuronal populations, cortical principal neurons, forebrain interneurons, or striatal medium spiny neurons, were tested for (1) sustained food reward-seeking when reward was absent, (2) reward-seeking under a progressive ratio schedule of reinforcement, and (3) persistent reward-seeking after a footshock punishment. Mutant mice with genetic deletion of GluN2B in cortical principal neurons demonstrated attenuated suppression of reward-seeking during punishment. These mice performed normally on other behavioral measures, including an assay for pain sensitivity. Mutants with interneuronal or striatal GluN2B deletions were normal on all behavioral assays. Current findings offer novel evidence that loss of GluN2B-containing NMDARs expressed on principal neurons in the cortex results in reduced punished food reward-seeking. These data support the involvement of GluN2B subunit in cortical circuits regulating cognitive flexibility in a variety of settings, with implications for understanding the basis of inflexible behavior in neuropsychiatric disorders including obsessive-compulsive disorders (OCD) and addictions.

  10. The joint effect of tangible and non-tangible rewards on healthy food choices in children.

    Science.gov (United States)

    Grubliauskiene, Aiste; Verhoeven, Maxime; Dewitte, Siegfried

    2012-10-01

    This study investigated how a combination of tangible and non-tangible rewards can alter health-related decisions made by children. Children chose between an unhealthy food option (a bowl of potato crisps) and a healthy food option (a bowl of grapes) on two occasions. In the first round, we manipulated the expected tangible reward and praise. The tangible reward was manipulated by means of a game that the child received upon choosing the healthy product, and the praise was manipulated by means of the teacher's applause and smiles if the child selected the healthy option. The second trial occurred three days after the first trial using the same food item options. Neither tangible rewards nor praise influenced the children's choices by themselves, but combining the two substantially increased the children's likelihood of selecting the healthy food choice. The data were consistent with a reattribution process akin to social labelling. Although initially externally motivated to select the healthy option, the children who received praise appeared to interpret their choice as internally motivated and therefore continued to select the healthy option even in the absence of reward. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Link Between Increased Satiety Gut Hormones and Reduced Food Reward After Gastric Bypass Surgery for Obesity.

    Science.gov (United States)

    Goldstone, Anthony P; Miras, Alexander D; Scholtz, Samantha; Jackson, Sabrina; Neff, Karl J; Pénicaud, Luc; Geoghegan, Justin; Chhina, Navpreet; Durighel, Giuliana; Bell, Jimmy D; Meillon, Sophie; le Roux, Carel W

    2016-02-01

    Roux-en-Y gastric bypass (RYGB) surgery is an effective long-term intervention for weight loss maintenance, reducing appetite, and also food reward, via unclear mechanisms. To investigate the role of elevated satiety gut hormones after RYGB, we examined food hedonic-reward responses after their acute post-prandial suppression. These were randomized, placebo-controlled, double-blind, crossover experimental medicine studies. Two groups, more than 5 months after RYGB for obesity (n = 7-11), compared with nonobese controls (n = 10), or patients after gastric banding (BAND) surgery (n = 9) participated in the studies. Studies were performed after acute administration of the somatostatin analog octreotide or saline. In one study, patients after RYGB, and nonobese controls, performed a behavioral progressive ratio task for chocolate sweets. In another study, patients after RYGB, and controls after BAND surgery, performed a functional magnetic resonance imaging food picture evaluation task. Octreotide increased both appetitive food reward (breakpoint) in the progressive ratio task (n = 9), and food appeal (n = 9) and reward system blood oxygen level-dependent signal (n = 7) in the functional magnetic resonance imaging task, in the RYGB group, but not in the control groups. Octreotide suppressed postprandial plasma peptide YY, glucagon-like peptide-1, and fibroblast growth factor-19 after RYGB. The reduction in plasma peptide YY with octreotide positively correlated with the increase in brain reward system blood oxygen level-dependent signal in RYGB/BAND subjects, with a similar trend for glucagon-like peptide-1. Enhanced satiety gut hormone responses after RYGB may be a causative mechanism by which anatomical alterations of the gut in obesity surgery modify behavioral and brain reward responses to food.

  12. Ghrelin mediates stress-induced food-reward behavior in mice.

    Science.gov (United States)

    Chuang, Jen-Chieh; Perello, Mario; Sakata, Ichiro; Osborne-Lawrence, Sherri; Savitt, Joseph M; Lutter, Michael; Zigman, Jeffrey M

    2011-07-01

    The popular media and personal anecdotes are rich with examples of stress-induced eating of calorically dense "comfort foods." Such behavioral reactions likely contribute to the increased prevalence of obesity in humans experiencing chronic stress or atypical depression. However, the molecular substrates and neurocircuits controlling the complex behaviors responsible for stress-based eating remain mostly unknown, and few animal models have been described for probing the mechanisms orchestrating this response. Here, we describe a system in which food-reward behavior, assessed using a conditioned place preference (CPP) task, is monitored in mice after exposure to chronic social defeat stress (CSDS), a model of prolonged psychosocial stress, featuring aspects of major depression and posttraumatic stress disorder. Under this regime, CSDS increased both CPP for and intake of high-fat diet, and stress-induced food-reward behavior was dependent on signaling by the peptide hormone ghrelin. Also, signaling specifically in catecholaminergic neurons mediated not only ghrelin's orexigenic, antidepressant-like, and food-reward behavioral effects, but also was sufficient to mediate stress-induced food-reward behavior. Thus, this mouse model has allowed us to ascribe a role for ghrelin-engaged catecholaminergic neurons in stress-induced eating.

  13. To eat or not to eat: Effects of food availability on reward system activity during food picture viewing.

    Science.gov (United States)

    Blechert, Jens; Klackl, Johannes; Miedl, Stephan F; Wilhelm, Frank H

    2016-04-01

    Neuroimaging studies have started to explore the role of food characteristics (e.g., calorie-content) and psychological factors (e.g., restrained eating, craving) for the human appetitive system, motivated by the significant health implications of food-choice, overeating and overweight/obesity. However, one key aspect of modern food environments, food availability, especially of high energy foods, has not been adequately modeled in experimental research. Food that is immediately available for consumption could elicit stronger reward system activity and associated cognitive control than food that is not currently available for consumption and this could vary as a function of energy density. To examine this question, 32 healthy participants (16 women) underwent functional magnetic resonance imaging while passively viewing available foods - i.e. foods that could be eaten during and after the experiment - and unavailable foods of either high or low-caloric density in a 2 × 2 design. Available compared to unavailable foods elicited higher palatability ratings as well as stronger neural activation in the orbitofrontal cortex (OFC), amygdala, and left caudate nucleus as well as in the anterior cingulate cortex (ACC) - and thus structures implicated in reward and appetitive motivation as well as cognitive control, respectively. Availability effects in the caudate were mainly attributable to the high calorie condition (availability × calorie density interaction). These neuroimaging results support the contention that foods are particularly rewarding when immediately available and particularly so when high in caloric density. Thus, our results are consistent with health promoting interventions utilizing a nudging approach, i.e. aiming at decreasing accessibility of high calorie and increasing accessibility of low calorie foods in daily life. Results also imply that controlling/manipulating food availability may be an important methodological aspect in neuroscientific

  14. [Hidden allergens in processed food : An update from the consumer's point of view].

    Science.gov (United States)

    Schnadt, Sabine; Pfaff, Sylvia

    2016-07-01

    Despite improved allergen labelling and careful avoidance strategies, hidden allergens in food remain a substantial risk for unintended reactions for consumers with food allergies. New data from a survey of the German Allergy and Asthma Association (Deutscher Allergie- und Asthmabund - DAAB) shows a slight decrease in the number of consumers that report allergic reactions to prepacked food. Still, 75 % (compared to 85 % in 2008) have experienced at least one allergic reaction after eating a prepacked food. In more than half of the cases, the reaction was classified as severe (with airway and/or cardiovascular symptoms such as respiratory distress, loss of blood pressure or anaphylactic shock). Again, more than 40 % (2008: 47 %, 2015: 42 %) reported that no information on the presence of the food allergens had been present on the label either as ingredients or as precautionary allergen labelling (PAL). Different possibilities are discussed under which food allergens may not be recognized or recognizable by consumers with food allergies, such as allergen labelling that is not easy to understand, unexpected occurrence of allergens as well as recipe changes in known foods. Examples are given as well as proposals for the improvement of the situation in order to better meet the goals of food information regulations to enable consumers with food allergies to make "informed choices which are safe for them" (Quote Regulation (EU) 1169/2011 - Reason 24).

  15. Dietary Factors Affect Food Reward and Motivation to Eat

    NARCIS (Netherlands)

    Pandit, Rahul; Mercer, Julian G.; Overduin, Joost; la Fleur, Susanne E.; Adan, Roger A. H.

    2012-01-01

    The propensity to indulge in unhealthy eating and overconsumption of palatable food is a crucial determinant in the rising prevalence of obesity in today's society. The tendency to consume palatable foods in quantities that exceed energy requirements has been linked to an addiction-like process.

  16. Differential effects of fructose versus glucose on brain and appetitive responses to food cues and decisions for food rewards.

    Science.gov (United States)

    Luo, Shan; Monterosso, John R; Sarpelleh, Kayan; Page, Kathleen A

    2015-05-19

    Prior studies suggest that fructose compared with glucose may be a weaker suppressor of appetite, and neuroimaging research shows that food cues trigger greater brain reward responses in a fasted relative to a fed state. We sought to determine the effects of ingesting fructose versus glucose on brain, hormone, and appetitive responses to food cues and food-approach behavior. Twenty-four healthy volunteers underwent two functional magnetic resonance imaging (fMRI) sessions with ingestion of either fructose or glucose in a double-blinded, random-order cross-over design. fMRI was performed while participants viewed images of high-calorie foods and nonfood items using a block design. After each block, participants rated hunger and desire for food. Participants also performed a decision task in which they chose between immediate food rewards and delayed monetary bonuses. Hormones were measured at baseline and 30 and 60 min after drink ingestion. Ingestion of fructose relative to glucose resulted in smaller increases in plasma insulin levels and greater brain reactivity to food cues in the visual cortex (in whole-brain analysis) and left orbital frontal cortex (in region-of-interest analysis). Parallel to the neuroimaging findings, fructose versus glucose led to greater hunger and desire for food and a greater willingness to give up long-term monetary rewards to obtain immediate high-calorie foods. These findings suggest that ingestion of fructose relative to glucose results in greater activation of brain regions involved in attention and reward processing and may promote feeding behavior.

  17. Interactive effects of reward sensitivity and residential fast-food restaurant exposure on fast-food consumption.

    Science.gov (United States)

    Paquet, Catherine; Daniel, Mark; Knäuper, Bärbel; Gauvin, Lise; Kestens, Yan; Dubé, Laurette

    2010-03-01

    Local fast-food environments have been increasingly linked to obesity and related outcomes. Individuals who are more sensitive to reward-related cues might be more responsive to such environments. This study aimed to assess the moderating role of sensitivity to reward on the relation between residential fast-food restaurant exposure and fast-food consumption. Four hundred fifteen individuals (49.6% men; mean age: 34.7 y) were sampled from 7 Montreal census tracts stratified by socioeconomic status and French/English language. The frequency of fast-food restaurant visits in the previous week was self-reported. Sensitivity to reward was self-reported by using the Behavioral Activation System (BAS) scale. Fast-food restaurant exposure within 500 m of the participants' residence was determined by using a Geographic Information System. Main and interactive effects of the BAS and fast-food restaurant exposure on fast-food consumption were tested with logistic regression models that accounted for clustering of observations and participants' age, sex, education, and household income. Regression results showed a significant interaction between BAS and fast-food restaurant exposure (P food restaurant exposure and consumption was positive for the highest tertile (odds ratio: 1.49; 95% CI: 1.20, 1.84; P < 0.001) but null for the intermediate (odds ratio: 1.03; 95% CI: 0.80, 1.34; P = 0.81) and lowest (odds ratio: 0.84; 95% CI: 0.51, 1.37; P = 0.49) tertiles. Reward-sensitive individuals may be more responsive to unhealthful cues in their immediate environment.

  18. How Food as a Reward Is Detrimental to Children's Health, Learning, and Behavior

    Science.gov (United States)

    Fedewa, Alicia L.; Davis, Matthew Cody

    2015-01-01

    Background: Despite small- and wide-scale prevention efforts to curb obesity, the percentage of children classified as overweight and obese has remained relatively consistent in the last decade. As school personnel are increasingly pressured to enhance student performance, many educators use food as a reward to motivate and reinforce positive…

  19. Activation of MAPK Is Necessary for Long-Term Memory Consolidation Following Food-Reward Conditioning

    Science.gov (United States)

    Ribeiro, Maria J.; Schofield, Michael G.; Kemenes, Ildiko; O'Shea, Michael; Kemenes, Gyorgy; Benjamin, Paul R.

    2005-01-01

    Although an important role for the mitogen-activated protein kinase (MAPK) has been established for memory consolidation in a variety of learning paradigms, it is not known if this pathway is also involved in appetitive classical conditioning. We address this question by using a single-trial food-reward conditioning paradigm in the freshwater…

  20. High on food: the interaction between the neural circuits for feeding and for reward.

    Science.gov (United States)

    Liu, Jing-Jing; Mukherjee, Diptendu; Haritan, Doron; Ignatowska-Jankowska, Bogna; Liu, Ji; Citri, Ami; Pang, Zhiping P

    2015-04-01

    Hunger, mostly initiated by a deficiency in energy, induces food seeking and intake. However, the drive toward food is not only regulated by physiological needs, but is motivated by the pleasure derived from ingestion of food, in particular palatable foods. Therefore, feeding is viewed as an adaptive motivated behavior that involves integrated communication between homeostatic feeding circuits and reward circuits. The initiation and termination of a feeding episode are instructed by a variety of neuronal signals, and maladaptive plasticity in almost any component of the network may lead to the development of pathological eating disorders. In this review we will summarize the latest understanding of how the feeding circuits and reward circuits in the brain interact. We will emphasize communication between the hypothalamus and the mesolimbic dopamine system and highlight complexities, discrepancies, open questions and future directions for the field.

  1. Moving beyond energy homeostasis: new roles for glucagon-like peptide-1 in food and drug reward.

    Science.gov (United States)

    Reddy, India A; Stanwood, Gregg D; Galli, Aurelio

    2014-07-01

    Glucagon-like peptide-1 (GLP-1), a hormone and neuropeptide, is known to regulate energy homeostasis in part through an established central role in controlling food intake. Historically this central role has largely been attributed to GLP-1 receptor signaling in the brainstem and hypothalamus. However, emerging data indicate that GLP-1 also contributes to non-homeostatic regulation of food reward and motivated behaviors in brain reward centers, including the ventral tegmental area and nucleus accumbens. The hypothesis that GLP-1 signaling modulates reward circuitry has provided the impetus for studies demonstrating that GLP-1 attenuates reward for psychostimulants and alcohol. Here, we examine current evidence for GLP-1-mediated regulation of food and drug reward and use these findings to hypothesize mechanisms of action within brain reward centers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Comparing the effects of food restriction and overeating on brain reward systems.

    Science.gov (United States)

    Avena, Nicole M; Murray, Susan; Gold, Mark S

    2013-10-01

    Both caloric restriction and overeating have been shown to affect neural processes associated with reinforcement. Both preclinical and some clinical studies have provided evidence that food restriction may increase reward sensitivity, and while there are mixed findings regarding the effects of overeating on reward sensitivity, there is strong evidence linking this behavior with changes in reward-related brain regions. Evidence of these changes comes in part from findings that show that such eating patterns are associated with increased drug use. The data discussed here regarding the differential effects of various eating patterns on reward systems may be particularly relevant to the aging population, as this population has been shown to exhibit altered reward sensitivity and decreased caloric consumption. Moreover, members of this population appear to be increasingly affected by the current obesity epidemic. Food, like alcohol or drugs, can stimulate its own consumption and produce similar neurochemical changes in the brain. Age-related loss of appetite, decreased eating, and caloric restriction are hypothesized to be associated with changes in the prevalence of substance misuse, abuse, and dependence seen in this cohort. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Impulsivity in binge eating disorder: food cues elicit increased reward responses and disinhibition.

    Directory of Open Access Journals (Sweden)

    Kathrin Schag

    Full Text Available BACKGROUND: Binge eating disorder (BED represents a distinct eating disorder diagnosis. Current approaches assume increased impulsivity to be one factor leading to binge eating and weight gain. We used eye tracking to investigate both components of impulsivity, namely reward sensitivity and rash-spontaneous behaviour towards food in BED for the first time. METHODS: Overweight and obese people with BED (BED+; n = 25, without BED (BED-; n = 26 and healthy normal-weight controls (NWC; n = 25 performed a free exploration paradigm measuring reward sensitivity (experiment 1 and a modified antisaccade paradigm measuring disinhibited, rash-spontaneous behaviour (experiment 2 using food and nonfood stimuli. Additionally, trait impulsivity was assessed. RESULTS: In experiment 1, all participants located their initial fixations more often on food stimuli and BED+ participants gazed longer on food stimuli in comparison with BED- and NWC participants. In experiment 2, BED+ participants had more difficulties inhibiting saccades towards food and nonfood stimuli compared with both other groups in first saccades, and especially towards food stimuli in second saccades and concerning sequences of first and second saccades. BED- participants did not differ significantly from NWC participants in both experiments. Additionally, eye tracking performance was associated with self-reported reward responsiveness and self-control. CONCLUSIONS: According to these results, food-related reward sensitivity and rash-spontaneous behaviour, as the two components of impulsivity, are increased in BED in comparison with weight-matched and normal-weight controls. This indicates that BED represents a neurobehavioural phenotype of obesity that is characterised by increased impulsivity. Interventions for BED should target these special needs of affected patients.

  4. Ghrelin signalling on food reward: a salient link between the gut and the mesolimbic system.

    Science.gov (United States)

    Perello, M; Dickson, S L

    2015-06-01

    'Hunger is the best spice' is an old and wise saying that acknowledges the fact that almost any food tastes better when we are hungry. The neurobiological underpinnings of this lore include activation of the brain's reward system and the stimulation of this system by the hunger-promoting hormone ghrelin. Ghrelin is produced largely from the stomach and levels are higher preprandially. The ghrelin receptor is expressed in many brain areas important for feeding control, including not only the hypothalamic nuclei involved in energy balance regulation, but also reward-linked areas such as the ventral tegmental area. By targeting the mesoaccumbal dopamine neurones of the ventral tegmental area, ghrelin recruits pathways important for food reward-related behaviours that show overlap with but are also distinct from those important for food intake. We review a variety of studies that support the notion that ghrelin signalling at the level of the mesolimbic system is one of the key molecular substrates that provides a physiological signal connecting gut and reward pathways. © 2014 The Authors. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology.

  5. Food additives, food and the concept of 'food addiction': Is stimulation of the brain reward circuit by food sufficient to trigger addiction?

    Science.gov (United States)

    Onaolapo, A Y; Onaolapo, O J

    2018-04-12

    In the last few years, the concept of 'food addiction' has continued to gain popularity, with human and animal studies demonstrating the differential effects of foods that are high in fat, sugar or protein on appetite, satiety, eating behaviour and the development of food addiction. However, a number of studies have disputed the occurrence of food addiction in humans. Questions have also arisen regarding the possible impacts that food additives may have on the development of food addiction or eating disorders. Also, it is known that alterations in food composition and the presence of food additives (flavour enhancers, sugars, sugar substitutes, and non-nutritive sweeteners) are factors that generally influence the sensory perception of food. Our understanding of the potential roles of central neurotransmitters (such as dopamine) and certain neuropeptides in the evolution of food addiction is also evolving; but presently, there isn't sufficient scientific evidence to consider any food ingredient, micronutrient or standard food-additive as addictive. In this review, the relevant literatures dealing with the concept of 'food addiction' are examined, and the factors which may predispose to food addiction are discussed. The possible influences that flavour-enhancers, sugars, sugar substitutes and non-nutritive sweeteners may exert on central neurotransmission, neurotransmitter/receptor interactions, appetite, satiety, conditioned- preferences and the brain reward system are also highlighted. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. The endocannabinoid system and appetite: relevance for food reward

    NARCIS (Netherlands)

    Jager, G.; Witkamp, R.F.

    2014-01-01

    Mounting evidence substantiates the central role of the endocannabinoid system (ECS) in the modulation of both homeostatic and hedonic elements of appetite and food intake. Conversely, feeding status and dietary patterns directly influence activity of the ECS. Following a general introduction on the

  7. Female Emotional Eaters Show Abnormalities in Consummatory and Anticipatory Food Reward

    Science.gov (United States)

    Bohon, Cara; Stice, Eric; Spoor, Sonja

    2009-01-01

    Objective To test the hypothesis that emotional eaters show greater neural activation in response to food intake and anticipated food intake than nonemotional eaters and whether these differences are amplified during a negative versus neutral mood state. Method Female emotional eaters and nonemotional eaters (N = 21) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless control solution while in a negative and neutral mood. Results Emotional eaters showed greater activation in the parahippocampal gyrus and anterior cingulate (ACC) in response to anticipated receipt of milkshake and greater activation in the pallidum, thalamus, and ACC in response to receipt of milkshake during a negative relative to a neutral mood. In contrast, nonemotional eaters showed decreased activation in reward regions during a negative versus a neutral mood. Discussion Results suggest that emotional eating is related to increased anticipatory and consummatory food reward, but only during negative mood. PMID:19040270

  8. The effect of REM sleep deprivation on motivation for food reward.

    Science.gov (United States)

    Hanlon, Erin C; Andrzejewski, Matthew E; Harder, Bridgette K; Kelley, Ann E; Benca, Ruth M

    2005-08-30

    Prolonged sleep deprivation in rats produces a characteristic syndrome consisting of an increase in food intake yet a decrease in weight. Moreover, the increase in food intake generally precedes the weight loss, suggesting that sleep deprivation may affect appetitive behaviors. Using the multiple platform method to produce rapid eye movement (REM) sleep deprivation, we investigated the effect of REM sleep deprivation (REMSD) on motivation for food reward utilizing food-reinforced operant tasks. In acquisition or maintenance of an operant task, REM sleep-deprived rats, with or without simultaneous food restriction, decreased responding for sucrose pellet reward in comparison to controls, despite the fact that all REM sleep-deprived rats lost weight. Furthermore, the overall response deficit of the REM sleep-deprived rats was due to a within-session decline in responding. REM sleep-deprived rats showed evidence of understanding the contingency of the task comparable to controls throughout deprivation period, suggesting that the decrements in responding were not primarily related to deficits in learning or memory. Rather, REM sleep deprivation appears to alter systems involved in motivational processes, reward, and/or attention.

  9. High-Intensity Interval Training, Appetite, and Reward Value of Food in the Obese.

    Science.gov (United States)

    Martins, Catia; Aschehoug, Irina; Ludviksen, Marit; Holst, Jens; Finlayson, Graham; Wisloff, Ulrik; Morgan, Linda; King, Neil; Kulseng, Bård

    2017-09-01

    Studies on the effect of chronic interval training on appetite in the obese population are scarce. The aim of this study was to determine the effect of 12 wk of isocaloric programs of moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), or short-duration HIIT on subjective feelings of appetite, appetite-related hormones, and reward value of food in sedentary obese individuals. Forty-six sedentary obese individuals (30 women and 16 men), with a body mass index of 33.3 ± 2.9 kg·m and age of 34.4 ± 8.8 yr, were randomly assigned to one of the three training groups: MICT (n = 14), HIIT (n = 16), or short-duration HIIT (n = 16). Exercise was performed three times per week for 12 wk. Subjective feelings of appetite and plasma levels of acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1 were measured before and after a standard breakfast (every 30 min up to 3 h), before and after the exercise intervention. Fat and sweet taste preferences and food reward were measured using the Leeds Food Preference Questionnaire. A significant increase in fasting and postprandial feelings of hunger was observed with the exercise intervention (P = 0.01 and P = 0.048, respectively), but no effect of group and no interaction. No significant effect of exercise intervention, group, or interaction was found on fasting or postprandial subjective feelings of fullness, desire to eat, and prospective food consumption or plasma concentration of acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1. No changes in food preference or reward over time, differences between groups, or interactions were found. This study suggests that chronic HIIT has no independent effect on appetite or food reward when compared with an isocaloric program of MICT in obese individuals.

  10. Ghrelin Signalling on Food Reward: A Salient Link Between the Gut and the Mesolimbic System

    OpenAIRE

    Perello, M.; Dickson, S. L.

    2015-01-01

    ?Hunger is the best spice? is an old and wise saying that acknowledges the fact that almost any food tastes better when we are hungry. The neurobiological underpinnings of this lore include activation of the brain's reward system and the stimulation of this system by the hunger?promoting hormone ghrelin. Ghrelin is produced largely from the stomach and levels are higher preprandially. The ghrelin receptor is expressed in many brain areas important for feeding control, including not only the h...

  11. Galanin-Expressing GABA Neurons in the Lateral Hypothalamus Modulate Food Reward and Noncompulsive Locomotion.

    Science.gov (United States)

    Qualls-Creekmore, Emily; Yu, Sangho; Francois, Marie; Hoang, John; Huesing, Clara; Bruce-Keller, Annadora; Burk, David; Berthoud, Hans-Rudolf; Morrison, Christopher D; Münzberg, Heike

    2017-06-21

    The lateral hypothalamus (LHA) integrates reward and appetitive behavior and is composed of many overlapping neuronal populations. Recent studies associated LHA GABAergic neurons (LHA GABA ), which densely innervate the ventral tegmental area (VTA), with modulation of food reward and consumption; yet, LHA GABA projections to the VTA exclusively modulated food consumption, not reward. We identified a subpopulation of LHA GABA neurons that coexpress the neuropeptide galanin (LHA Gal ). These LHA Gal neurons also modulate food reward, but lack direct VTA innervation. We hypothesized that LHA Gal neurons may represent a subpopulation of LHA GABA neurons that mediates food reward independent of direct VTA innervation. We used chemogenetic activation of LHA Gal or LHA GABA neurons in mice to compare their role in feeding behavior. We further analyzed locomotor behavior to understand how differential VTA connectivity and transmitter release in these LHA neurons influences this behavior. LHA Gal or LHA GABA neuronal activation both increased operant food-seeking behavior, but only activation of LHA GABA neurons increased overall chow consumption. Additionally, LHA Gal or LHA GABA neuronal activation similarly induced locomotor activity, but with striking differences in modality. Activation of LHA GABA neurons induced compulsive-like locomotor behavior; while LHA Gal neurons induced locomotor activity without compulsivity. Thus, LHA Gal neurons define a subpopulation of LHA GABA neurons without direct VTA innervation that mediate noncompulsive food-seeking behavior. We speculate that the striking difference in compulsive-like locomotor behavior is also based on differential VTA innervation. The downstream neural network responsible for this behavior and a potential role for galanin as neuromodulator remains to be identified. SIGNIFICANCE STATEMENT The lateral hypothalamus (LHA) regulates motivated feeding behavior via GABAergic LHA neurons. The molecular identity of LHA

  12. Leptin is associated with exaggerated brain reward and emotion responses to food images in adolescent obesity.

    Science.gov (United States)

    Jastreboff, Ania M; Lacadie, Cheryl; Seo, Dongju; Kubat, Jessica; Van Name, Michelle A; Giannini, Cosimo; Savoye, Mary; Constable, R Todd; Sherwin, Robert S; Caprio, Sonia; Sinha, Rajita

    2014-11-01

    In the U.S., an astonishing 12.5 million children and adolescents are now obese, predisposing 17% of our nation's youth to metabolic complications of obesity, such as type 2 diabetes (T2D). Adolescent obesity has tripled over the last three decades in the setting of food advertising directed at children. Obese adults exhibit increased brain responses to food images in motivation-reward pathways. These neural alterations may be attributed to obesity-related metabolic changes, which promote food craving and high-calorie food (HCF) consumption. It is not known whether these metabolic changes affect neural responses in the adolescent brain during a crucial period for establishing healthy eating behaviors. Twenty-five obese (BMI 34.4 kg/m2, age 15.7 years) and fifteen lean (BMI 20.96 kg/m2, age 15.5 years) adolescents underwent functional MRI during exposure to HCF, low-calorie food (LCF), and nonfood (NF) visual stimuli 2 h after isocaloric meal consumption. Brain responses to HCF relative to NF cues increased in obese versus lean adolescents in striatal-limbic regions (i.e., putamen/caudate, insula, amygdala) (P < 0.05, family-wise error [FWE]), involved in motivation-reward and emotion processing. Higher endogenous leptin levels correlated with increased neural activation to HCF images in all subjects (P < 0.05, FWE). This significant association between higher circulating leptin and hyperresponsiveness of brain motivation-reward regions to HCF images suggests that dysfunctional leptin signaling may contribute to the risk of overconsumption of these foods, thus further predisposing adolescents to the development of obesity and T2D. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  13. Food as a reward in the classroom: school district policies are associated with practices in US public elementary schools.

    Science.gov (United States)

    Turner, Lindsey; Chriqui, Jamie F; Chaloupka, Frank J

    2012-09-01

    The use of food as a reward for good student behavior or academic performance is discouraged by many national organizations, yet this practice continues to occur in schools. Our multiyear cross-sectional study examined the use of food as a reward in elementary schools and evaluated the association between district policies and school practices. School data were gathered during the 2007-2008, 2008-2009, and 2009-2010 school years via mail-back surveys (N=2,069) from respondents at nationally representative samples of US public elementary schools (1,525 unique schools, 544 of which also participated for a second year). During every year, the corresponding district policy for each school was gathered and coded for provisions pertaining to the use of food as a reward. School practices did not change over time and as of the 2009-2010 school year, respondents in 42.1% and 40.7% of schools, respectively, indicated that food was not used as a reward for academic performance or for good student behavior. In multivariate logistic regression analyses controlling for school characteristics and year, having a district policy that prohibited the use of food as a reward was significantly associated with school respondents reporting that food was not used as a reward for academic performance (Preward than were respondents in the South and Northeast. As of 2009-2010, only 11.9% of the districts in our study prohibited the use of food as a reward. Strengthening district policies may reduce the use of food rewards in elementary schools. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  14. Obesity is marked by distinct functional connectivity in brain networks involved in food reward and salience.

    Science.gov (United States)

    Wijngaarden, M A; Veer, I M; Rombouts, S A R B; van Buchem, M A; Willems van Dijk, K; Pijl, H; van der Grond, J

    2015-01-01

    We hypothesized that brain circuits involved in reward and salience respond differently to fasting in obese versus lean individuals. We compared functional connectivity networks related to food reward and saliency after an overnight fast (baseline) and after a prolonged fast of 48 h in lean versus obese subjects. We included 13 obese (2 males, 11 females, BMI 35.4 ± 1.2 kg/m(2), age 31 ± 3 years) and 11 lean subjects (2 males, 9 females, BMI 23.2 ± 0.5 kg/m(2), age 28 ± 3 years). Resting-state functional magnetic resonance imaging scans were made after an overnight fast (baseline) and after a prolonged 48 h fast. Functional connectivity of the amygdala, hypothalamus and posterior cingulate cortex (default-mode) networks was assessed using seed-based correlations. At baseline, we found a stronger connectivity between hypothalamus and left insula in the obese subjects. This effect diminished upon the prolonged fast. After prolonged fasting, connectivity of the hypothalamus with the dorsal anterior cingulate cortex (dACC) increased in lean subjects and decreased in obese subjects. Amygdala connectivity with the ventromedial prefrontal cortex was stronger in lean subjects at baseline, which did not change upon the prolonged fast. No differences in posterior cingulate cortex connectivity were observed. In conclusion, obesity is marked by alterations in functional connectivity networks involved in food reward and salience. Prolonged fasting differentially affected hypothalamic connections with the dACC and the insula between obese and lean subjects. Our data support the idea that food reward and nutrient deprivation are differently perceived and/or processed in obesity. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Operant behavior to obtain palatable food modifies neuronal plasticity in the brain reward circuit.

    Science.gov (United States)

    Guegan, Thomas; Cutando, Laura; Ayuso, Eduard; Santini, Emanuela; Fisone, Gilberto; Bosch, Fatima; Martinez, Albert; Valjent, Emmanuel; Maldonado, Rafael; Martin, Miquel

    2013-02-01

    Palatability enhances food intake by hedonic mechanisms that prevail over caloric necessities. Different studies have demonstrated the role of endogenous cannabinoids in the mesocorticolimbic system in controlling food hedonic value and consumption. We hypothesize that the endogenous cannabinoid system could also be involved in the development of food-induced behavioral alterations, such as food-seeking and binge-eating, by a mechanism that requires neuroplastic changes in the brain reward pathway. For this purpose, we evaluated the role of the CB1 cannabinoid receptor (CB1-R) in the behavioral and neuroplastic changes induced by operant training for standard, highly caloric or highly palatable isocaloric food using different genetics, viral and pharmacological approaches. Neuroplasticity was evaluated by measuring changes in dendritic spine density in neurons previously labeled with the dye DiI. Only operant training to obtain highly palatable isocaloric food induced neuroplastic changes in neurons of the nucleus accumbens shell and prefrontal cortex that were associated to changes in food-seeking behavior. These behavioral and neuroplastic modifications induced by highly palatable isocaloric food were dependent on the activity of the CB1-R. Neuroplastic changes induced by highly palatable isocaloric food are similar to those produced by some drugs of abuse and may be crucial in the alteration of food-seeking behavior leading to overweight and obesity. Copyright © 2012 Elsevier B.V. and ECNP. All rights reserved.

  16. Competitor suppresses neuronal representation of food reward in the nucleus accumbens/medial striatum of domestic chicks.

    Science.gov (United States)

    Amita, Hidetoshi; Matsushima, Toshiya

    2014-07-15

    To investigate the role of social contexts in controlling the neuronal representation of food reward, we recorded single neuron activity in the medial striatum/nucleus accumbens of domestic chicks and examined whether activities differed between two blocks with different contexts. Chicks were trained in an operant task to associate light-emitting diode color cues with three trial types that differed in the type of food reward: no reward (S-), a small reward/short-delay option (SS), and a large reward/long-delay alternative (LL). Amount and duration of reward were set such that both of SS and LL were chosen roughly equally. Neurons showing distinct cue-period activity in rewarding trials (SS and LL) were identified during an isolation block, and activity patterns were compared with those recorded from the same neuron during a subsequent pseudo-competition block in which another chick was allowed to forage in the same area, but was separated by a transparent window. In some neurons, cue-period activity was lower in the pseudo-competition block, and the difference was not ascribed to the number of repeated trials. Comparison at neuronal population level revealed statistically significant suppression in the pseudo-competition block in both SS and LL trials, suggesting that perceived competition generally suppressed the representation of cue-associated food reward. The delay- and reward-period activities, however, did not significantly different between blocks. These results demonstrate that visual perception of a competitive forager per se weakens the neuronal representation of predicted food reward. Possible functional links to impulse control are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Individual differences in anticipatory activity to food rewards predict cue-induced appetitive 50-kHz calls in rats.

    Science.gov (United States)

    Brenes, Juan C; Schwarting, Rainer K W

    2015-10-01

    Reward-related stimuli come to acquire incentive salience through Pavlovian learning and become capable of controlling reward-oriented behaviors. Here, we examined individual differences in anticipatory activity elicited by reward-related cues as indicative of how animals attribute incentive salience to otherwise neutral stimuli. Since adult rats can signal incentive motivation states through ultrasonic vocalizations (USVs) at around 50-kHz, such calls were recorded in food-deprived rats trained to associate cues with food rewards, which were subsequently devalued by satiation.We found that the extent to which animals developed conditioned anticipatory activity to food cues while food deprived determined the level of cue-induced appetitive USVs while sated. Re-exposure to reward cues after a free-testing period reinstated USVs, invigorated reward seeking and consumption, and again, increases in calling occurred only in animals with high levels of cue-induced anticipatory activity. Reward-experienced rats systemically challenged with the catecholamine agonist amphetamine or with the dopamine receptor antagonist flupenthixol showed attenuated responses to these drugs, especially for USVs and in subjects with high levels of cue-induced anticipatory activity. Our results suggest that individuals prone to attribute incentive salience to reward cues showed heightened reward-induced USVs which were reliably expressed over time and persisted despite physiological needs being fulfilled. Also, prone subjects seemed to undergo particular adaptations in their dopaminergic system related with incentive learning. Our findings may have translational relevance in preclinical research modeling compulsive disorders, which may be due to excessive attribution of incentive salience to reward cues, such as overeating, pathological gambling, and drug addiction.

  18. Anaphylaxis after eating Italian pizza containing buckwheat as the hidden food allergen.

    Science.gov (United States)

    Heffler, E; Guida, G; Badiu, I; Nebiolo, F; Rolla, G

    2007-01-01

    A 20-year-old woman developed anaphylaxis after eating pizza on 4 different occasions in 2 restaurants. Both restaurants made their pizza dough with a mixture of wheat and buckwheat flours. A prick-to-prick test with buckwheat flour was positive. Skin prick tests and specific immunoglobulin E responses to soybean and peanut were weakly positive while the response to buckwheat was negative. We ruled out a pathogenic role for peanut and soybean because the patient usually eats both with no signs of allergic reaction. Double-blind, placebo-controlled food challenges with buckwheat flour were positive after the administration of a cumulative dose of 2.3 g of the culprit flour. To our knowledge, our report describes the first case of anaphylaxis after intake of buckwheat flour as the hidden allergen in pizza dough.

  19. Great apes (Pan paniscus, Pan troglodytes, Gorilla gorilla, Pongo abelii) follow visual trails to locate hidden food.

    Science.gov (United States)

    Völter, Christoph J; Call, Josep

    2014-05-01

    Whether nonhuman primates understand causal relations beyond mere associations is still a matter of debate. We presented all four species of nonhuman great apes (N = 36) with a choice between 2 opaque, upside down cups after displacing them out of sight from their starting positions. Crucially, 1 of them had left a yogurt trail behind it. Great apes spontaneously used the trail to select the yogurt baited cup. Follow-up experiments demonstrated that chimpanzees distinguished trails based on the temporal order of cause and effect by ignoring trails that were already present before the reward was hidden. Additionally, chimpanzees did not select cups based on the amount of yogurt near them but instead preferred cups that signaled the endpoint of the trail. We conclude that apes' choices reveal sensitivity to a causal relation between cause (reward) and effect (trail) including their temporal order. ©2014 APA, all rights reserved.

  20. Detection of hidden hazelnut protein in food by IgY-based indirect competitive enzyme-immunoassay

    NARCIS (Netherlands)

    Baumgartner, S.; Bremer, M.G.E.G.; Kemmers - Voncken, A.E.M.; Smits, N.G.E.; Haasnoot, W.; Banks, J.; Reece, P.; Danks, C.; Tomkies, V.; Immer, U.; Schmitt, K.; Krska, R.

    2004-01-01

    The development of an indirect competitive enzyme-immunoassay for the detection of hidden hazelnut protein in complex food matrices is described. A sensitive and selective polyclonal antibody was raised by immunisation of laying hens with protein extracts from roasted hazelnuts. In contrast to

  1. Oleic Acid in the Ventral Tegmental Area Inhibits Feeding, Food Reward, and Dopamine Tone.

    Science.gov (United States)

    Hryhorczuk, Cecile; Sheng, Zhenyu; Décarie-Spain, Léa; Giguère, Nicolas; Ducrot, Charles; Trudeau, Louis-Éric; Routh, Vanessa H; Alquier, Thierry; Fulton, Stephanie

    2018-02-01

    Long-chain fatty acids (FAs) act centrally to decrease food intake and hepatic glucose production and alter hypothalamic neuronal activity in a manner that depends on FA type and cellular transport proteins. However, it is not known whether FAs are sensed by ventral tegmental area (VTA) dopamine (DA) neurons to control food-motivated behavior and DA neurotransmission. We investigated the impact of the monounsaturated FA oleate in the VTA on feeding, locomotion, food reward, and DA neuronal activity and DA neuron expression of FA-handling proteins and FA uptake. A single intra-VTA injection of oleate, but not of the saturated FA palmitate, decreased food intake and increased locomotor activity. Furthermore, intra-VTA oleate blunted the rewarding effects of high-fat/sugar food in an operant task and inhibited DA neuronal firing. Using sorted DA neuron preparations from TH-eGFP mice we found that DA neurons express FA transporter and binding proteins, and are capable of intracellular transport of long-chain FA. Finally, we demonstrate that a transporter blocker attenuates FA uptake into DA neurons and blocks the effects of intra-VTA oleate to decrease food-seeking and DA neuronal activity. Together, these results suggest that DA neurons detect FA and that oleate has actions in the VTA to suppress DA neuronal activity and food seeking following cellular incorporation. These findings highlight the capacity of DA neurons to act as metabolic sensors by responding not only to hormones but also to FA nutrient signals to modulate food-directed behavior.

  2. Steep discounting of delayed monetary and food rewards in obesity: a meta-analysis.

    Science.gov (United States)

    Amlung, M; Petker, T; Jackson, J; Balodis, I; MacKillop, J

    2016-08-01

    An increasing number of studies have investigated delay discounting (DD) in relation to obesity, but with mixed findings. This meta-analysis synthesized the literature on the relationship between monetary and food DD and obesity, with three objectives: (1) to characterize the relationship between DD and obesity in both case-control comparisons and continuous designs; (2) to examine potential moderators, including case-control v. continuous design, money v. food rewards, sample sex distribution, and sample age (18 years); and (3) to evaluate publication bias. From 134 candidate articles, 39 independent investigations yielded 29 case-control and 30 continuous comparisons (total n = 10 278). Random-effects meta-analysis was conducted using Cohen's d as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger tests, meta-regression of publication year and effect size, and imputation of missing studies. The primary analysis revealed a medium effect size across studies that was highly statistically significant (d = 0.43, p food rewards and child/adolescent samples. Limited evidence of publication bias was present, although the Begg-Mazumdar test and meta-regression suggested a slightly diminishing effect size over time. Steep DD of food and money appears to be a robust feature of obesity that is relatively consistent across the DD assessment methodologies and study designs examined. These findings are discussed in the context of research on DD in drug addiction, the neural bases of DD in obesity, and potential clinical applications.

  3. Obese adults have visual attention bias for food cue images: evidence for altered reward system function.

    Science.gov (United States)

    Castellanos, E H; Charboneau, E; Dietrich, M S; Park, S; Bradley, B P; Mogg, K; Cowan, R L

    2009-09-01

    The major aim of this study was to investigate whether the motivational salience of food cues (as reflected by their attention-grabbing properties) differs between obese and normal-weight subjects in a manner consistent with altered reward system function in obesity. A total of 18 obese and 18 normal-weight, otherwise healthy, adult women between the ages of 18 and 35 participated in an eye-tracking paradigm in combination with a visual probe task. Eye movements and reaction time to food and non-food images were recorded during both fasted and fed conditions in a counterbalanced design. Eating behavior and hunger level were assessed by self-report measures. Obese individuals had higher scores than normal-weight individuals on self-report measures of responsiveness to external food cues and vulnerability to disruptions in control of eating behavior. Both obese and normal-weight individuals demonstrated increased gaze duration for food compared to non-food images in the fasted condition. In the fed condition, however, despite reduced hunger in both groups, obese individuals maintained the increased attention to food images, whereas normal-weight individuals had similar gaze duration for food and non-food images. Additionally, obese individuals had preferential orienting toward food images at the onset of each image. Obese and normal-weight individuals did not differ in reaction time measures in the fasted or fed condition. Food cue incentive salience is elevated equally in normal-weight and obese individuals during fasting. Obese individuals retain incentive salience for food cues despite feeding and decreased self-report of hunger. Sensitization to food cues in the environment and their dysregulation in obese individuals may play a role in the development and/or maintenance of obesity.

  4. Food Seeking in a Risky Environment: A Method for Evaluating Risk and Reward Value in Food Seeking and Consumption in Mice.

    Science.gov (United States)

    Lockie, Sarah H; McAuley, Clare V; Rawlinson, Sasha; Guiney, Natalie; Andrews, Zane B

    2017-01-01

    Most studies that measure food intake in mice do so in the home cage environment. This necessarily means that mice do not engage in food seeking before consumption, a behavior that is ubiquitous in free-living animals. We modified and validated several commonly used anxiety tests to include a palatable food reward within the anxiogenic zone. This allowed us to assess risk-taking behavior in food seeking in mice in response to different metabolic stimuli. We modified the open field test and the light/dark box by placing palatable peanut butter chips within a designated food zone inside the anxiogenic zone of each apparatus. We then assessed parameters of the interaction with the food reward. Fasted mice or mice treated with ghrelin showed increased consumption and increased time spent in the food zone immediately around the food reward compared to ad libitum fed mice or mice treated with saline. However, fasted mice treated with IP glucose before exposure to the behavioral arena showed reduced time in the food zone compared to fasted controls, indicating that acute metabolic signals can modify the assessment of safety in food seeking in a risky environment. The tests described in this study will be useful in assessing risk processing and incentive salience of food reward, which are intrinsic components of food acquisition outside of the laboratory environment, in a range of genetic and pharmacological models.

  5. Pavlovian conditioning to food reward as a function of eating disorder risk.

    Science.gov (United States)

    Astur, Robert S; Palmisano, Alexandra N; Hudd, Ellie C; Carew, Andrew W; Deaton, Bonnie E; Kuhney, Franchesca S; Niezrecki, Rachel N; Santos, Melissa

    2015-09-15

    The aim of this experiment was to examine the extent to which eating disorder risk affects the strength of food-reward conditioning. Eighty food-restricted undergraduates were placed into a VR environment consisting of two visually distinct rooms. Participants underwent multiple pairing sessions in which they were confined into one of the two rooms and explored a VR environment. Room A was paired with real-life M&Ms for three sessions, and Room B was paired with no food for three sessions. After a short delay, a test session was administered, and participants were given free access to the entire VR environment for 5 min. Participants also completed the Eating Attitudes Test (EAT-26; [11]), which is a standard screening tool of eating disorder risk. Participants displayed a significant conditioned place preference for the VR room previously paired with food, and they displayed a significant explicit preference for the M&M-paired room in a forced-choice test. There was a significant positive correlation between place preference strength and scores on the dieting subscale of the EAT-26. Additionally, ratings of the no-food room were significantly lower as dieting scores increased. This suggests that components of eating disorder risk can influence basic conditioning strength to places associated with food reward. For both males and females, additional correlations between eating disorder risk subscales and conditioning variables are discussed, and implications for future research are proposed in hopes of understanding how conditioning paradigms can provide insight into treating and preventing eating disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Central dopaminergic circuitry controlling food intake and reward: implications for the regulation of obesity.

    Science.gov (United States)

    Vucetic, Zivjena; Reyes, Teresa M

    2010-01-01

    Prevalence of obesity in the general population has increased in the past 15 years from 15% to 35%. With increasing obesity, the coincident medical and social consequences are becoming more alarming. Control over food intake is crucial for the maintenance of body weight and represents an important target for the treatment of obesity. Central nervous system mechanisms responsible for control of food intake have evolved to sense the nutrient and energy levels in the organism and to coordinate appropriate responses to adjust energy intake and expenditure. This homeostatic system is crucial for maintenance of stable body weight over long periods of time of uneven energy availability. However, not only the caloric and nutritional value of food but also hedonic and emotional aspects of feeding affect food intake. In modern society, the increased availability of highly palatable and rewarding (fat, sweet) food can significantly affect homeostatic balance, resulting in dysregulated food intake. This review will focus on the role of hypothalamic and mesolimbic/mesocortical dopaminergic (DA) circuitry in coding homeostatic and hedonic signals for the regulation of food intake and maintenance of caloric balance. The interaction of dopamine with peripheral and central indices of nutritional status (e.g., leptin, ghrelin, neuropeptide Y), and the susceptibility of the dopamine system to prenatal insults will be discussed. Additionally, the importance of alterations in dopamine signaling that occur coincidently with obesity will be addressed.

  7. Acute stress and food-related reward activation in the brain during food choice during eating in the absence of hunger.

    Science.gov (United States)

    Born, J M; Lemmens, S G T; Rutters, F; Nieuwenhuizen, A G; Formisano, E; Goebel, R; Westerterp-Plantenga, M S

    2010-01-01

    Stress results in eating in the absence of hunger, possibly related to food reward perception. Stress decreases food reward perception. Determine the effect of acute stress on food choice and food choice reward-related brain activity. Nine females (BMI = 21.5 + or - 2.2 kg/m(2), age = 24.3 + or - 3.5 years). Fasted subjects came twice to randomly complete either a rest or stress condition. Per session, two functional MRI scans were made, wherein the subjects chose the subsequent meal (food images). The rewarding value of the food was measured as liking and wanting. Food characteristics (for example, crispiness, fullness of taste and so on), energy intake, amount of each macronutrient chosen, plasma cortisol and Visual Analog Scale (VAS) hunger and satiety were measured. Fasted state was confirmed by high hunger (80 + or - 5 mm VAS). Breakfast energy intake (3 + or - 1 MJ) and liking were similar in all conditions. Wanting was lower postprandially (Delta = -0.3 items/category, Phunger (-42 mm VAS, Pchoice for crispiness and fullness of taste (Pfood choice for more crispiness and fullness of taste. The changes in putamen activation may reflect specifically decreased reward prediction sensitivity.

  8. Food and drug reward: overlapping circuits in human obesity and addiction.

    Science.gov (United States)

    Volkow, N D; Wang, G J; Fowler, J S; Tomasi, D; Baler, R

    2012-01-01

    Both drug addiction and obesity can be defined as disorders in which the saliency value of one type of reward (drugs and food, respectively) becomes abnormally enhanced relative to, and at the expense of others. This model is consistent with the fact that both drugs and food have powerful reinforcing effects-partly mediated by dopamine increases in the limbic system-that, under certain circumstances or in vulnerable individuals, could overwhelm the brain's homeostatic control mechanisms. Such parallels have generated significant interest in understanding the shared vulnerabilities and trajectories between addiction and obesity. Now, brain imaging discoveries have started to uncover common features between these two conditions and to delineate some of the overlapping brain circuits whose dysfunctions may explain stereotypic and related behavioral deficits in human subjects. These results suggest that both obese and drug-addicted individuals suffer from impairments in dopaminergic pathways that regulate neuronal systems associated not only with reward sensitivity and incentive motivation, but also with conditioning (memory/learning), impulse control (behavioural inhibition), stress reactivity, and interoceptive awareness. Here, we integrate findings predominantly derived from positron emission tomography that shed light on the role of dopamine in drug addiction and in obesity, and propose an updated working model to help identify treatment strategies that may benefit both of these conditions.

  9. Food and drug reward: overlapping circuits in human obesity and addiction

    Energy Technology Data Exchange (ETDEWEB)

    Volkow N. D.; Wang G.; Volkow, N.D.; Wang, G.-J.; Fowler, J.S.; Tomasi, D.; Baler, R.

    2012-12-01

    Both drug addiction and obesity can be defined as disorders in which the saliency value of one type of reward (drugs and food, respectively) becomes abnormally enhanced relative to, and at the expense of others. This model is consistent with the fact that both drugs and food have powerful reinforcing effects - partly mediated by dopamine increases in the limbic system - that, under certain circumstances or in vulnerable individuals, could overwhelm the brain's homeostatic control mechanisms. Such parallels have generated significant interest in understanding the shared vulnerabilities and trajectories between addiction and obesity. Now, brain imaging discoveries have started to uncover common features between these two conditions and to delineate some of the overlapping brain circuits whose dysfunctions may explain stereotypic and related behavioral deficits in human subjects. These results suggest that both obese and drug addicted individuals suffer from impairments in dopaminergic pathways that regulate neuronal systems associated not only with reward sensitivity and incentive motivation, but also with conditioning (memory/learning), impulse control (behavioral inhibition), stress reactivity and interoceptive awareness. Here, we integrate findings predominantly derived from positron emission tomography that investigate the role of dopamine in drug addiction and in obesity and propose an updated working model to help identify treatment strategies that may benefit both of these conditions.

  10. Food and drug reward: overlapping circuits in human obesity and addiction

    International Nuclear Information System (INIS)

    Volkow, N.D.; Wang, G.J.; Fowler, J.S.; Tomasi, D.; Baler, R.

    2012-01-01

    Both drug addiction and obesity can be defined as disorders in which the saliency value of one type of reward (drugs and food, respectively) becomes abnormally enhanced relative to, and at the expense of others. This model is consistent with the fact that both drugs and food have powerful reinforcing effects - partly mediated by dopamine increases in the limbic system - that, under certain circumstances or in vulnerable individuals, could overwhelm the brain's homeostatic control mechanisms. Such parallels have generated significant interest in understanding the shared vulnerabilities and trajectories between addiction and obesity. Now, brain imaging discoveries have started to uncover common features between these two conditions and to delineate some of the overlapping brain circuits whose dysfunctions may explain stereotypic and related behavioral deficits in human subjects. These results suggest that both obese and drug addicted individuals suffer from impairments in dopaminergic pathways that regulate neuronal systems associated not only with reward sensitivity and incentive motivation, but also with conditioning (memory/learning), impulse control (behavioral inhibition), stress reactivity and interoceptive awareness. Here, we integrate findings predominantly derived from positron emission tomography that investigate the role of dopamine in drug addiction and in obesity and propose an updated working model to help identify treatment strategies that may benefit both of these conditions.

  11. Integration of reward signalling and appetite regulating peptide systems in the control of food-cue responses.

    Science.gov (United States)

    Reichelt, A C; Westbrook, R F; Morris, M J

    2015-11-01

    Understanding the neurobiological substrates that encode learning about food-associated cues and how those signals are modulated is of great clinical importance especially in light of the worldwide obesity problem. Inappropriate or maladaptive responses to food-associated cues can promote over-consumption, leading to excessive energy intake and weight gain. Chronic exposure to foods rich in fat and sugar alters the reinforcing value of foods and weakens inhibitory neural control, triggering learned, but maladaptive, associations between environmental cues and food rewards. Thus, responses to food-associated cues can promote cravings and food-seeking by activating mesocorticolimbic dopamine neurocircuitry, and exert physiological effects including salivation. These responses may be analogous to the cravings experienced by abstaining drug addicts that can trigger relapse into drug self-administration. Preventing cue-triggered eating may therefore reduce the over-consumption seen in obesity and binge-eating disorder. In this review we discuss recent research examining how cues associated with palatable foods can promote reward-based feeding behaviours and the potential involvement of appetite-regulating peptides including leptin, ghrelin, orexin and melanin concentrating hormone. These peptide signals interface with mesolimbic dopaminergic regions including the ventral tegmental area to modulate reactivity to cues associated with palatable foods. Thus, a novel target for anti-obesity therapeutics is to reduce non-homeostatic, reward driven eating behaviour, which can be triggered by environmental cues associated with highly palatable, fat and sugar rich foods. © 2015 The British Pharmacological Society.

  12. African elephants can use human pointing cues to find hidden food.

    Science.gov (United States)

    Smet, Anna F; Byrne, Richard W

    2013-10-21

    How animals gain information from attending to the behavior of others has been widely studied, driven partly by the importance of referential pointing in human cognitive development [1-4], but species differences in reading human social cues remain unexplained. One explanation is that this capacity evolved during domestication [5, 6], but it may be that only those animals able to interpret human-like social cues were successfully domesticated. Elephants are a critical taxon for this question: despite their longstanding use by humans, they have never been domesticated [7]. Here we show that a group of 11 captive African elephants, seven of them significantly as individuals, could interpret human pointing to find hidden food. We suggest that success was not due to prior training or extensive learning opportunities. Elephants successfully interpreted pointing when the experimenter's proximity to the hiding place was varied and when the ostensive pointing gesture was visually subtle, suggesting that they understood the experimenter's communicative intent. The elephant's native ability in interpreting social cues may have contributed to its long history of effective use by man. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Chronic blockade or constitutive deletion of the serotonin transporter reduces operant responding for food reward.

    Science.gov (United States)

    Sanders, Amy Cecilia; Hussain, Ali J; Hen, René; Zhuang, Xiaoxi

    2007-11-01

    The therapeutic effects of chronic selective serotonin reuptake inhibitors (SSRIs) are well documented, yet the elementary behavioral processes that are affected by such treatment have not been fully investigated. We report here the effects of chronic fluoxetine treatment and genetic deletion of the serotonin transporter (SERT) on food reinforced behavior in three paradigms: the progressive ratio operant task, the concurrent choice operant task, and the Pavlovian-to-Instrumental transfer task. We consistently find that chronic pharmacological blockade or genetic deletion of SERT result in similar behavioral consequences: reduced operant responding for natural reward. This is in line with previous studies reporting declines in operant responding for drugs and intracranial self-stimulation with fluoxetine treatment, suggesting that the effect of SERT blockade can be generalized to different reward types. Detailed analyses of behavioral parameters indicate that this reduction in operant responding affect both goal-directed and non-goal-directed behaviors without affecting the Pavlovian cue-triggered excessive operant responding. In addition, both pharmacological and genetic manipulations reduce locomotor activity in the open field novel environment. Our data contrast with the effect of dopamine in increasing operant responding for natural reward specifically in goal-directed behaviors and in increasing Pavlovian cue-triggered excessive operant responding. Serotonin and dopamine have been proposed to serve opposing functions in motivational processes. Our data suggest that their interactions do not result in simple opponency. The fact that pharmacological blockade and genetic deletion of SERT have similar behavioral consequences reinforces the utility of the SERT null mice for investigation of the mechanisms underlying chronic SSRIs treatment.

  14. Stingless bees (Melipona scutellaris) learn to associate footprint cues at food sources with a specific reward context.

    Science.gov (United States)

    Roselino, Ana Carolina; Rodrigues, André Vieira; Hrncir, Michael

    2016-10-01

    Foraging insects leave chemical footprints on flowers that subsequent foragers may use as indicators for recent flower visits and, thus, potential resource depletion. Accordingly, foragers should reject food sources presenting these chemical cues. Contrasting this assumption, experimental studies in stingless bees (Apidae, Meliponini), so far, demonstrated an attractive effect of footprints. These findings lead to doubts about the meaning of these chemical cues in natural foraging contexts. Here, we asked whether foragers of stingless bees (Melipona scutellaris) use footprints according to the previously experienced reward level of visited food sources. Bees were trained to artificial flower patches, at which the reward of a flower either decreased or, alternatively, increased after a visit by a forager. Individuals were allowed a total of nine foraging bouts to the patch, after which their preference for visited or unvisited flowers was tested. In the choice tests, bees trained under the decreasing reward context preferred unvisited flowers, whereas individuals trained under the increasing reward context preferred visited flowers. Foragers without experience chose randomly between visited and unvisited flowers. These results demonstrate that M. scutellaris learns to associate unspecific footprint cues at food sources with differential, specific reward contexts, and uses these chemical cues accordingly for their foraging decisions.

  15. Central oxytocin and food intake: focus on macronutrient-driven reward

    Directory of Open Access Journals (Sweden)

    Anica eKlockars

    2015-04-01

    Full Text Available Centrally acting oxytocin (OT is known to terminate food consumption in response to excessive stomach distension, increase in salt loading and presence of toxins. Hypothalamic-hindbrain OT pathways facilitate these aspects of OT-induced hypophagia. However, recent discoveries have implicated OT in modifications of feeding via reward circuits: OT has been found to differentially affect consumption of individual macronutrients in choice and no-choice paradigms. In this mini-review, we focus on presenting and interpreting evidence that defines OT as a key component of mechanisms that reduce eating for pleasure and shape macronutrient preferences. We also provide remarks on challenges in integrating the knowledge on physiological and pathophysiological states in which both OT activity and macronutrient preferences are affected.

  16. A healthy trend: less food used in fundraising and as rewards and incentives in Minnesota middle and high schools.

    Science.gov (United States)

    Kubik, Martha Y; Farbakhsh, Kian; Lytle, Leslie A

    2013-04-01

    To assess change in the 4-year prevalence (2006-2009) of the use of food in school fundraising and as rewards and incentives for students, following implementation of federal legislation in the USA in 2006. Serial cross-sectional design using trend analysis to assess school-level data collected over four consecutive years from 2006/2007 to 2009/2010. Minneapolis/St. Paul, MN. Convenience sample of middle and high schools participating in two longitudinal, aetiological studies that examined youth, their environment and obesity-related factors. A significant and sustained decrease was demonstrated in the use of low-nutrient, energy-dense foods in school fundraising activities and the use of food and food coupons as rewards and incentives by teachers and school staff. Results support the utility of policy and legislative action as a tool for creating healthy, sustainable environmental change.

  17. Dopamine in the nucleus accumbens core, but not shell, increases during signaled food reward and decreases during delayed extinction.

    Science.gov (United States)

    Biesdorf, C; Wang, A-L; Topic, B; Petri, D; Milani, H; Huston, J P; de Souza Silva, M A

    2015-09-01

    Microdialysis studies in rat have generally shown that appetitive stimuli release dopamine (DA) in the nucleus accumbens (NAc) shell and core. Here we examined the release of DA in the NAc during delivery of reward (food) and during extinction of food reward in the freely moving animal by use of in vivo microdialysis and HPLC. Fifty-two male Wistar rats were trained to receive food reward associated with appearance of cue-lights in a Skinner-box during in vivo microdialysis. Different behavioral protocols were used to assess the effects of extinction on DA and its metabolites. Results Exp. 1: (a) During a 20-min period of cued reward delivery, DA increased significantly in the NAc core, but not shell subregion; (b) for the next 60min period half of the rats underwent immediate extinction (with the CS light presented during non-reward) and the other half did not undergo extinction to the cue lights (CS was not presented during non-reward). DA remained significantly increased in both groups, providing no evidence for a decrease in DA during extinction in either NAc core or shell regions. (c) In half of the animals of the group that was not subjected to extinction, the cue lights were turned on for 30min, thus, initiating extinction to cue CS at a 1h delay from the period of reward. In this group DA in the NAc core, but not shell, significantly decreased. Behavioral analysis showed that while grooming is an indicator of extinction-induced behavior, glances toward the cue-lights (sign tracking) are an index of resistance to extinction. Results Exp. 2: (a) As in Exp. 1, during a 30-min period of cued reward delivery, DA levels again increased significantly in the NAc core but not in the NAc shell. (b) When extinction (the absence of reward with the cue lights presented) was administered 24h after the last reward session, DA again significantly decreased in the NAc core, but not in the NAc shell. (a) These results confirm the importance of DA release in the NAc for

  18. Female emotional eaters show abnormalities in consummatory and anticipatory food reward: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Bohon, Cara; Stice, Eric; Spoor, Sonja

    2009-04-01

    To test the hypothesis that emotional eaters show greater neural activation in response to food intake and anticipated food intake than nonemotional eaters and whether these differences are amplified during a negative versus neutral mood state. Female emotional eaters and nonemotional eaters (N = 21) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless control solution while in a negative and neutral mood. Emotional eaters showed greater activation in the parahippocampal gyrus and anterior cingulate (ACC) in response to anticipated receipt of milkshake and greater activation in the pallidum, thalamus, and ACC in response to receipt of milkshake during a negative relative to a neutral mood. In contrast, nonemotional eaters showed decreased activation in reward regions during a negative versus a neutral mood. Results suggest that emotional eating is related to increased anticipatory and consummatory food reward, but only during negative mood. (c) 2008 by Wiley Periodicals, Inc.

  19. Visual cues given by humans are not sufficient for Asian elephants (Elephas maximus) to find hidden food.

    Science.gov (United States)

    Plotnik, Joshua M; Pokorny, Jennifer J; Keratimanochaya, Titiporn; Webb, Christine; Beronja, Hana F; Hennessy, Alice; Hill, James; Hill, Virginia J; Kiss, Rebecca; Maguire, Caitlin; Melville, Beckett L; Morrison, Violet M B; Seecoomar, Dannah; Singer, Benjamin; Ukehaxhaj, Jehona; Vlahakis, Sophia K; Ylli, Dora; Clayton, Nicola S; Roberts, John; Fure, Emilie L; Duchatelier, Alicia P; Getz, David

    2013-01-01

    Recent research suggests that domesticated species--due to artificial selection by humans for specific, preferred behavioral traits--are better than wild animals at responding to visual cues given by humans about the location of hidden food. \\Although this seems to be supported by studies on a range of domesticated (including dogs, goats and horses) and wild (including wolves and chimpanzees) animals, there is also evidence that exposure to humans positively influences the ability of both wild and domesticated animals to follow these same cues. Here, we test the performance of Asian elephants (Elephas maximus) on an object choice task that provides them with visual-only cues given by humans about the location of hidden food. Captive elephants are interesting candidates for investigating how both domestication and human exposure may impact cue-following as they represent a non-domesticated species with almost constant human interaction. As a group, the elephants (n = 7) in our study were unable to follow pointing, body orientation or a combination of both as honest signals of food location. They were, however, able to follow vocal commands with which they were already familiar in a novel context, suggesting the elephants are able to follow cues if they are sufficiently salient. Although the elephants' inability to follow the visual cues provides partial support for the domestication hypothesis, an alternative explanation is that elephants may rely more heavily on other sensory modalities, specifically olfaction and audition. Further research will be needed to rule out this alternative explanation.

  20. Visual cues given by humans are not sufficient for Asian elephants (Elephas maximus to find hidden food.

    Directory of Open Access Journals (Sweden)

    Joshua M Plotnik

    Full Text Available Recent research suggests that domesticated species--due to artificial selection by humans for specific, preferred behavioral traits--are better than wild animals at responding to visual cues given by humans about the location of hidden food. \\Although this seems to be supported by studies on a range of domesticated (including dogs, goats and horses and wild (including wolves and chimpanzees animals, there is also evidence that exposure to humans positively influences the ability of both wild and domesticated animals to follow these same cues. Here, we test the performance of Asian elephants (Elephas maximus on an object choice task that provides them with visual-only cues given by humans about the location of hidden food. Captive elephants are interesting candidates for investigating how both domestication and human exposure may impact cue-following as they represent a non-domesticated species with almost constant human interaction. As a group, the elephants (n = 7 in our study were unable to follow pointing, body orientation or a combination of both as honest signals of food location. They were, however, able to follow vocal commands with which they were already familiar in a novel context, suggesting the elephants are able to follow cues if they are sufficiently salient. Although the elephants' inability to follow the visual cues provides partial support for the domestication hypothesis, an alternative explanation is that elephants may rely more heavily on other sensory modalities, specifically olfaction and audition. Further research will be needed to rule out this alternative explanation.

  1. European Survey for Hidden Allergens in Food: A Case Study with Peanut and Hazelnut

    NARCIS (Netherlands)

    Baumgertner, S.; Furtler-Leitzenberger, L.; Molinelli, E.; Krska, R.; Immer, U.; Schmitt, K.; Bremer, M.; Haasnoot, W.; Danks, C.; Romkies, V.; Reece, P.; Wilson, P.; Kiening, M.; Weller, M.; Niessner, R.; Corsini, E.; Mendonca, S.

    2008-01-01

    During the EU-funded project Allergentest (QLK1-CT-2001-01151) a survey for the presence of hidden proteins of hazelnut and peanut in suspected pre-packed foodstuffs within EC member states was carried out to check the usefulness of the developed rapid test-kits. There were 11 participating

  2. High-Intensity Interval Training, Appetite, and Reward Value of Food in the Obese

    DEFF Research Database (Denmark)

    Martins, Catia; Aschehoug, Irina; Ludviksen, Marit

    2017-01-01

    PURPOSE: Studies on the effect of chronic interval training on appetite in the obese population are scarce. The aim of this study was to determine the effect of 12 wk of isocaloric programs of moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), or short......-duration HIIT on subjective feelings of appetite, appetite-related hormones, and reward value of food in sedentary obese individuals. METHODS: Forty-six sedentary obese individuals (30 women and 16 men), with a body mass index of 33.3 ± 2.9 kg·m and age of 34.4 ± 8.8 yr, were randomly assigned to one...... of the three training groups: MICT (n = 14), HIIT (n = 16), or short-duration HIIT (n = 16). Exercise was performed three times per week for 12 wk. Subjective feelings of appetite and plasma levels of acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1 were measured before and after a standard...

  3. Time of day influences the voluntary intake and behavioral response to methamphetamine and food reward.

    Science.gov (United States)

    Keith, Diana R; Hart, Carl L; Robotham, Margaret; Tariq, Maliha; Le Sauter, Joseph; Silver, Rae

    2013-09-01

    The circadian timing system influences a vast array of behavioral responses. Substantial evidence indicates a role for the circadian system in regulating reward processing. Here we explore time of day effects on drug anticipation, locomotor activity, and voluntary methamphetamine (MA) and food intake in animals with ad libitum food access. We compared responses to drug versus a palatable treat during their normal sleep times in early day (zeitgeber time (ZT) 0400) or late day (ZT 1000). In the first study, using a between-subjects design, mice were given daily 1-h access to either peanut butter (PB-Alone) or to a low or high concentration of MA mixed in PB (MA+PB). In study 2, we repeated the experiment using a within-subjects design in which mice could choose between PB-Alone and MA+PB at either ZT 0400 or 1000. In study 3, the effects of MA-alone were investigated by evaluating anticipatory activity preceding exposure to nebulized MA at ZT 0400 vs. ZT 1000. Time of day effects were observed for both drug and palatable treat, such that in the between groups design, animals showed greater intake, anticipatory activity, and post-ingestional activity in the early day. Furthermore, there were differences among mice in the amount of MA ingested but individuals were self-consistent in their daily intake. The results for the within-subjects experiment also revealed robust individual differences in preference for MA+PB or PB-Alone. Interestingly, time of day effects on intake were observed only for the preferred substance. Anticipatory activity preceding administration of MA by nebulization was also greater at ZT 0400 than ZT 1000. Finally, pharmacokinetic response to MA administered intraperitoneally did not vary as a function of time of administration. The results indicate that time of day is an important variable mediating the voluntary intake and behavioral effects of reinforcers. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Separation, Motivation, and Depression: Neonatal Isolation Reduces Food-Rewarded Operant Responding in Rats

    Science.gov (United States)

    Zellner, Margaret R.; Ranaldi, Robert

    2006-01-01

    One symptom of depression is loss of motivation, which can be defined as responsiveness to response-eliciting stimuli and quantified as reward-related behavioral output. Long-term changes in reward-related behavior have been shown to follow early life stress. Most rodent studies investigating the effects of postnatal separation, an early stress,…

  5. Discounting of Delayed Food Rewards in Pigeons and Rats: Is There a Magnitude Effect

    Science.gov (United States)

    Green, Leonard; Myerson, Joel; Holt, Daniel D.; Slavin, John R.; Estle, Sara J.

    2004-01-01

    Temporal discounting refers to the decrease in the present, subjective value of a reward as the time to its receipt increases. Results from humans have shown that a hyperbola-like function describes the form of the discounting function when choices involve hypothetical monetary rewards. In addition, magnitude effects have been reported in which…

  6. Activation of the GLP-1 receptors in the nucleus of the solitary tract reduces food reward behavior and targets the mesolimbic system.

    Directory of Open Access Journals (Sweden)

    Jennifer E Richard

    Full Text Available The gut/brain peptide, glucagon like peptide 1 (GLP-1, suppresses food intake by acting on receptors located in key energy balance regulating CNS areas, the hypothalamus or the hindbrain. Moreover, GLP-1 can reduce reward derived from food and motivation to obtain food by acting on its mesolimbic receptors. Together these data suggest a neuroanatomical segregation between homeostatic and reward effects of GLP-1. Here we aim to challenge this view and hypothesize that GLP-1 can regulate food reward behavior by acting directly on the hindbrain, the nucleus of the solitary tract (NTS, GLP-1 receptors (GLP-1R. Using two models of food reward, sucrose progressive ratio operant conditioning and conditioned place preference for food in rats, we show that intra-NTS microinjections of GLP-1 or Exendin-4, a stable analogue of GLP-1, inhibit food reward behavior. When the rats were given a choice between palatable food and chow, intra-NTS Exendin-4 treatment preferentially reduced intake of palatable food but not chow. However, chow intake and body weight were reduced by the NTS GLP-1R activation if chow was offered alone. The NTS GLP-1 activation did not alter general locomotor activity and did not induce nausea, measured by PICA. We further show that GLP-1 fibers are in close apposition to the NTS noradrenergic neurons, which were previously shown to provide a monosynaptic connection between the NTS and the mesolimbic system. Central GLP-1R activation also increased NTS expression of dopamine-β-hydroxylase, a key enzyme in noradrenaline synthesis, indicating a biological link between these two systems. Moreover, NTS GLP-1R activation altered the expression of dopamine-related genes in the ventral tegmental area. These data reveal a food reward-suppressing role of the NTS GLP-1R and indicate that the neurobiological targets underlying food reward control are not limited to the mesolimbic system, instead they are distributed throughout the CNS.

  7. Activation of the GLP-1 receptors in the nucleus of the solitary tract reduces food reward behavior and targets the mesolimbic system.

    Science.gov (United States)

    Richard, Jennifer E; Anderberg, Rozita H; Göteson, Andreas; Gribble, Fiona M; Reimann, Frank; Skibicka, Karolina P

    2015-01-01

    The gut/brain peptide, glucagon like peptide 1 (GLP-1), suppresses food intake by acting on receptors located in key energy balance regulating CNS areas, the hypothalamus or the hindbrain. Moreover, GLP-1 can reduce reward derived from food and motivation to obtain food by acting on its mesolimbic receptors. Together these data suggest a neuroanatomical segregation between homeostatic and reward effects of GLP-1. Here we aim to challenge this view and hypothesize that GLP-1 can regulate food reward behavior by acting directly on the hindbrain, the nucleus of the solitary tract (NTS), GLP-1 receptors (GLP-1R). Using two models of food reward, sucrose progressive ratio operant conditioning and conditioned place preference for food in rats, we show that intra-NTS microinjections of GLP-1 or Exendin-4, a stable analogue of GLP-1, inhibit food reward behavior. When the rats were given a choice between palatable food and chow, intra-NTS Exendin-4 treatment preferentially reduced intake of palatable food but not chow. However, chow intake and body weight were reduced by the NTS GLP-1R activation if chow was offered alone. The NTS GLP-1 activation did not alter general locomotor activity and did not induce nausea, measured by PICA. We further show that GLP-1 fibers are in close apposition to the NTS noradrenergic neurons, which were previously shown to provide a monosynaptic connection between the NTS and the mesolimbic system. Central GLP-1R activation also increased NTS expression of dopamine-β-hydroxylase, a key enzyme in noradrenaline synthesis, indicating a biological link between these two systems. Moreover, NTS GLP-1R activation altered the expression of dopamine-related genes in the ventral tegmental area. These data reveal a food reward-suppressing role of the NTS GLP-1R and indicate that the neurobiological targets underlying food reward control are not limited to the mesolimbic system, instead they are distributed throughout the CNS.

  8. Activation in brain energy regulation and reward centers by food cues varies with choice of visual stimulus.

    Science.gov (United States)

    Schur, E A; Kleinhans, N M; Goldberg, J; Buchwald, D; Schwartz, M W; Maravilla, K

    2009-06-01

    To develop a non-invasive method of studying brain mechanisms involved in energy homeostasis and appetite regulation in humans by using visual food cues that are relevant to individuals attempting weight loss. Functional magnetic resonance imaging (fMRI) was used to compare brain activation in regions of interest between groups of food photographs. Ten healthy, non-obese women who were not dieting for weight loss. Independent raters viewed food photographs and evaluated whether the foods depicted should be eaten by individuals attempting a calorically-restricted diet. Based on their responses, we categorized photographs into 'non-fattening' and 'fattening' food groups, the latter characterized by high-caloric content and usually also high-fat or high-sugar content. Blood oxygen level-dependent (BOLD) response was measured by fMRI while participants viewed photographs of 'fattening' food, 'non-fattening' food, and non-food objects. Viewing photographs of fattening food compared with non-food objects resulted in significantly greater activation in the brainstem; hypothalamus; left amygdala; left dorsolateral prefrontal cortex; left orbitofrontal cortex; right insular cortex; bilateral striatum, including the nucleus accumbens, caudate nucleus, and putamen; bilateral thalamus; and occipital lobe. By comparison, only the occipital region had greater activation by non-fattening food than by object photographs. Combining responses to all food types resulted in attenuation of activation in the brainstem, hypothalamus, and striatum. These findings suggest that, in non-obese women, neural circuits engaged in energy homeostasis and reward processing are selectively attuned to representations of high-calorie foods that are perceived as fattening. Studies to investigate hormonal action or manipulation of energy balance may benefit from fMRI protocols that contrast energy-rich food stimuli with non-food or low-calorie food stimuli.

  9. The Hidden Burden of Food Waste: The Double Energy Waste in Italy

    Directory of Open Access Journals (Sweden)

    Matteo Vittuari

    2016-08-01

    Full Text Available The energy intensity of modern food systems represents a major issue in a scenario of decreasing oil resources and increasing population. Beside the use of renewable energy, an increased efficiency in food systems could contribute to reduce fossil fuels dependence. In this sense, food losses and waste (FLW have crucial consequences on the energy balance. Based on the concept of “embodied energy”, food wastage can be framed as a double waste of energy, both in terms of non-consumed food energy and the inputs used for production. Secondary data regarding direct and indirect energy inputs and FLW have been collected for the Italian food chain to estimate the embodied energy of food waste. Since in 2011 the production and distribution of food implied the use of 822 PJ and 18 Mt of food was discarded, 67 PJ of food energy and 100 PJ of embodied energy were wasted. These figures are equivalent to 12.2% of the total nutritional energy output and to 1.3% of the final energy use in Italy, respectively. The concept of double energy waste sheds new light on the intertwined relationship between energy and food security, suggesting that appropriate food waste reduction policies could result in a higher food production level and relevant energy savings.

  10. Putting the brakes on the "drive to eat": Pilot effects of naltrexone and reward based eating on food cravings among obese women

    Science.gov (United States)

    Mason, Ashley E.; Laraia, Barbara; Daubenmier, Jennifer; Hecht, Frederick M.; Lustig, Robert H.; Puterman, Eli; Adler, Nancy; Dallman, Mary; Kiernan, Michaela; Gearhardt, Ashley N.; Epel, Elissa S.

    2015-01-01

    Purpose Obese individuals vary in their experience of food cravings and tendency to engage in reward-driven eating, both of which can be modulated by the neural reward system rather than physiological hunger. We examined two predictions in a sample of obese women: (1) whether opioidergic blockade reduced food-craving intensity, and (2) whether opioidergic blockade reduced an association between food-craving intensity and reward-driven eating, which is a trait-like index of three factors (lack of control over eating, lack of satiation, preoccupation with food). Methods Forty-four obese, pre-menopausal women completed the Reward-based Eating Drive (RED) scale at study start and daily food-craving intensity on 5 days on which they ingested either a pill-placebo (2 days), a 25mg naltrexone dose (1 day), or a standard 50mg naltrexone dose (2 days). Results Craving intensity was similar under naltrexone and placebo doses. The association between food-craving intensity and reward-driven eating significantly differed between placebo and 50mg naltrexone doses. Reward-driven eating and craving intensity were significantly positively associated under both placebo doses. As predicted, opioidergic blockade (for both doses 25mg and 50mg naltrexone) reduced this positive association between reward-driven eating and craving intensity to non-significance. Conclusions Opioidergic blockade did not reduce craving intensity; however, blockade reduced an association between trait-like reward-driven eating and daily food-craving intensity, and may help identify an important endophenotype within obesity. PMID:26164674

  11. The Hidden Burden of Food Waste: The Double Energy Waste in Italy

    OpenAIRE

    Matteo Vittuari; Fabio De Menna; Marco Pagani

    2016-01-01

    The energy intensity of modern food systems represents a major issue in a scenario of decreasing oil resources and increasing population. Beside the use of renewable energy, an increased efficiency in food systems could contribute to reduce fossil fuels dependence. In this sense, food losses and waste (FLW) have crucial consequences on the energy balance. Based on the concept of “embodied energy”, food wastage can be framed as a double waste of energy, both in terms of non-consumed food energ...

  12. Do cattle (Bos taurus) retain an association of a visual cue with a food reward for a year?

    Science.gov (United States)

    Hirata, Masahiko; Takeno, Nozomi

    2014-06-01

    Use of visual cues to locate specific food resources from a distance is a critical ability of animals foraging in a spatially heterogeneous environment. However, relatively little is known about how long animals can retain the learned cue-reward association without reinforcement. We compared feeding behavior of experienced and naive Japanese Black cows (Bos taurus) in discovering food locations in a pasture. Experienced animals had been trained to respond to a visual cue (plastic washtub) for a preferred food (grain-based concentrate) 1 year prior to the experiment, while naive animals had no exposure to the cue. Cows were tested individually in a test arena including tubs filled with the concentrate on three successive days (Days 1-3). Experienced cows located the first tub more quickly and visited more tubs than naive cows on Day 1 (usually P visual cue with a food reward within a day and retain the association for 1 year despite a slight decay. © 2014 Japanese Society of Animal Science.

  13. Effects of insulin and leptin in the ventral tegmental area and arcuate hypothalamic nucleus on food intake and brain reward function in female rats.

    Science.gov (United States)

    Bruijnzeel, Adrie W; Corrie, Lu W; Rogers, Jessica A; Yamada, Hidetaka

    2011-06-01

    There is evidence for a role of insulin and leptin in food intake, but the effects of these adiposity signals on the brain reward system are not well understood. Furthermore, the effects of insulin and leptin on food intake in females are underinvestigated. These studies investigated the role of insulin and leptin in the ventral tegmental area (VTA) and the arcuate hypothalamic nucleus (Arc) on food intake and brain reward function in female rats. The intracranial self-stimulation procedure was used to assess the effects of insulin and leptin on the reward system. Elevations in brain reward thresholds are indicative of a decrease in brain reward function. The bilateral administration of leptin into the VTA (15-500 ng/side) or Arc (15-150 ng/side) decreased food intake for 72 h. The infusion of leptin into the VTA or Arc resulted in weight loss during the first 48 (VTA) or 24 h (Arc) after the infusions. The administration of insulin (0.005-5 mU/side) into the VTA or Arc decreased food intake for 24 h but did not affect body weights. The bilateral administration of low, but not high, doses of leptin (15 ng/side) or insulin (0.005 mU/side) into the VTA elevated brain reward thresholds. Neither insulin nor leptin in the Arc affected brain reward thresholds. These studies suggest that a small increase in leptin or insulin levels in the VTA leads to a decrease in brain reward function. A relatively large increase in insulin or leptin levels in the VTA or Arc decreases food intake. Published by Elsevier B.V.

  14. Maternal "junk-food" feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring.

    Science.gov (United States)

    Ong, Z Y; Muhlhausler, B S

    2011-07-01

    Individuals exposed to high-fat, high-sugar diets before birth have an increased risk of obesity in later life. Recent studies have shown that these offspring exhibit increased preference for fat, leading to suggestions that perinatal exposure to high-fat, high-sugar foods results in permanent changes within the central reward system that increase the subsequent drive to overconsume palatable foods. The present study has determined the effect of a maternal "junk-food" diet on the expression of key components of the mesolimbic reward pathway in the offspring of rat dams at 6 wk and 3 mo of age. We show that offspring of junk-food-fed (JF) dams exhibit higher fat intake from weaning until at least 3 mo of age (males: 16 ± 0.6 vs. 11 ± 0.8 g/kg/d; females: 19 ± 1.3 vs. 13 ± 0.4 g/kg/d; Pjunk-food intake in postnatal life.

  15. Enhanced motivation for food reward induced by stress and attenuation by corticotrophin-releasing factor receptor antagonism in rats: implications for overeating and obesity.

    Science.gov (United States)

    Liu, Xiu

    2015-06-01

    Overeating beyond individuals' homeostatic needs critically contributes to obesity. The neurobehavioral mechanisms underlying the motivation to consume excessive foods with high calories are not fully understood. The present study examined whether a pharmacological stressor, yohimbine, enhances the motivation to procure food reward with an emphasis on comparisons between standard lab chow and high-fat foods. The effects of corticotropin-releasing factor (CRF) receptor blockade by a CRF1-selective antagonist NBI on the stress-enhanced motivation for food reward were also assessed. Male Sprague-Dawley rats with chow available ad libitum in their home cages were trained to press a lever under a progressive ratio schedule for deliveries of either standard or high-fat food pellets. For testing yohimbine stress effects, rats received an intraperitoneal administration of yohimbine 10 min before start of the test sessions. For testing effects of CRF1 receptor blockade on stress responses, NBI was administered 20 min prior to yohimbine challenge. The rats emitted higher levels of lever responses to procure the high-fat food pellets compared with their counterparts on standard food pellets. Yohimbine challenge facilitated lever responses for the reward in all of the rats, whereas the effect was more robust in the rats on high-fat food pellets compared with their counterparts on standard food pellets. An inhibitory effect of pretreatment with NBI was observed on the enhancing effect of yohimbine challenge but not on the responses under baseline condition without yohimbine administration. Stress challenge significantly enhanced the motivation of satiated rats to procure extra food reward, especially the high-fat food pellets. Activation of CRF1 receptors is required for the stress-enhanced motivation for food reward. These results may have implications for our better understanding of the biobehavioral mechanisms of overeating and obesity.

  16. Mechanisms and significance of brain glucose signaling in energy balance, glucose homeostasis, and food-induced reward.

    Science.gov (United States)

    Devarakonda, Kavya; Mobbs, Charles V

    2016-12-15

    The concept that hypothalamic glucose signaling plays an important role in regulating energy balance, e.g., as instantiated in the so-called "glucostat" hypothesis, is one of the oldest in the field of metabolism. However the mechanisms by which neurons in the hypothalamus sense glucose, and the function of glucose signaling in the brain, has been difficult to establish. Nevertheless recent studies probing mechanisms of glucose signaling have also strongly supported a role for glucose signaling in regulating energy balance, glucose homeostasis, and food-induced reward. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Imidacloprid slows the development of preference for rewarding food sources in bumblebees (Bombus impatiens).

    Science.gov (United States)

    Phelps, Jordan D; Strang, Caroline G; Gbylik-Sikorska, Malgorzata; Sniegocki, Tomasz; Posyniak, Andrzej; Sherry, David F

    2018-03-01

    Bee pollination is economically and ecologically vital and recent declines in bee populations are therefore a concern. One possible cause of bee declines is pesticide use. Bumblebees exposed to imidacloprid, a neonicotinoid pesticide, have been shown to be less efficient foragers and collect less pollen on foraging trips than unexposed bees. We investigated whether bumblebees (Bombus impatiens) chronically exposed to imidacloprid at field-realistic levels of 2.6 and 10 ppb showed learning deficits that could affect foraging. Bumblebees were tested for their ability to associate flower colour with reward value in a simulated foraging environment. Bumblebees completed 10 foraging trips in which they collected sucrose solution from artificial flowers that varied in sucrose concentration. The reward quality of each artificial flower was predicted by corolla colour. Unexposed bumblebees acquired a preference for feeding on the most rewarding flower colour on the second foraging trip, while bumblebees exposed at 2.6 and 10 ppb did not until their third and fifth trip, respectively. The delay in preference acquisition in exposed bumblebees may be due to reduced flower sampling and shorter foraging trips. These results show that bumblebees exposed to imidacloprid are slow to learn the reward value of flowers and this may explain previously observed foraging inefficiencies associated with pesticide exposure.

  18. Reward for food odors: an fMRI study of liking and wanting as a function of metabolic state and BMI.

    Science.gov (United States)

    Jiang, Tao; Soussignan, Robert; Schaal, Benoist; Royet, Jean-Pierre

    2015-04-01

    Brain reward systems mediate liking and wanting for food reward. Here, we explore the differential involvement of the following structures for these two components: the ventral and dorsal striatopallidal area, orbitofrontal cortex (OFC), anterior insula and anterior cingulate. Twelve healthy female participants were asked to rate pleasantness (liking of food and non-food odors) and the desire to eat (wanting of odor-evoked food) during event-related functional magnetic resonance imaging (fMRI). The subjective ratings and fMRI were performed in hunger and satiety states. Activations of regions of interest were compared as a function of task (liking vs wanting), odor category (food vs non-food) and metabolic state (hunger vs satiety). We found that the nucleus accumbens and ventral pallidum were differentially involved in liking or wanting during the hunger state, which suggests a reciprocal inhibitory influence between these structures. Neural activation of OFC subregions was correlated with either liking or wanting ratings, suggesting an OFC role in reward processing magnitude. Finally, during the hunger state, participants with a high body mass index exhibited less activation in neural structures underlying food reward processing. Our results suggest that food liking and wanting are two separable psychological constructs and may be functionally segregated within the cortico-striatopallidal circuit. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  19. Brain reward-system activation in response to anticipation and consumption of palatable food is altered by glucagon-like peptide-1 receptor activation in humans

    NARCIS (Netherlands)

    van Bloemendaal, L.; Veltman, D. J.; ten Kulve, J. S.; Groot, P. F. C.; Ruhe, H. G.; Barkhof, F.; Sloan, J. H.; Diamant, M.; Ijzerman, R. G.

    AimTo test the hypothesis that food intake reduction after glucagon-like peptide-1 (GLP-1) receptor activation is mediated through brain areas regulating anticipatory and consummatory food reward. MethodsAs part of a larger study, we determined the effects of GLP-1 receptor activation on brain

  20. Brain reward-system activation in response to anticipation and consumption of palatable food is altered by glucagon-like peptide-1 receptor activation in humans

    NARCIS (Netherlands)

    van Bloemendaal, L.; Veltman, D. J.; ten Kulve, J. S.; Groot, P. F. C.; Ruhé, H. G.; Barkhof, F.; Sloan, J. H.; Diamant, M.; Ijzerman, R. G.

    2015-01-01

    To test the hypothesis that food intake reduction after glucagon-like peptide-1 (GLP-1) receptor activation is mediated through brain areas regulating anticipatory and consummatory food reward. As part of a larger study, we determined the effects of GLP-1 receptor activation on brain responses to

  1. Brain reward-system activation in response to anticipation and consumption of palatable food is altered by glucagon-like peptide-1 receptor activation in humans

    NARCIS (Netherlands)

    van Bloemendaal, L.; Veltman, D.J.; ten Kulve, J.S.; Groot, P.F.C.; Ruhe, H.G.; Barkhof, F.; Sloan, J.H.; Diamant, M.; IJzerman, R.G.

    2015-01-01

    Aim: To test the hypothesis that food intake reduction after glucagon-like peptide-1 (GLP-1) receptor activation is mediated through brain areas regulating anticipatory and consummatory food reward. Methods: As part of a larger study, we determined the effects of GLP-1 receptor activation on brain

  2. REM sleep deprivation produces a motivational deficit for food reward that is reversed by intra-accumbens amphetamine in rats.

    Science.gov (United States)

    Hanlon, Erin C; Benca, Ruth M; Baldo, Brian A; Kelley, Ann E

    2010-10-30

    Prolonged sleep deprivation in rats produces a characteristic syndrome of increase in food intake accompanied by, paradoxically, decrease in weight, suggesting a potential alteration in motivation for food reward. Using the multiple platform method to produce REM sleep deprivation (REMSD), we investigated the effect of REMSD on motivation for food reinforcement with a progressive ratio operant task, which yields a measure of the motor effort that a hungry animal is willing to expend to obtain food (the point at which the animal quits responding is termed the "break-point"). We found that REMSD rats decreased the break point for sucrose pellet reinforcement in comparison to controls, as revealed by a within-session decline in responding. This behavioral deficit is similar to that observed in rats with diminished dopamine transmission within the nucleus accumbens (Acb), and, considering that stimulants are frequently used in the clinical setting to reverse the effects of sleepiness, we examined the effect of systemic or intra-Acb amphetamine on break point in REMSD rats. Animals were given either systemic or intra-Acb amphetamine injections on days 3 and 5 of REMSD. Systemic amphetamine (0.1, 0.5, or 2.5mg/kg) did not increase break point in REMSD rats. In contrast, intra-Acb infusions of amphetamine (1, 10, or 30μg/0.5μl bilaterally) reversed the REMSD-induced suppression of progressive ratio responding. Specifically, the two higher doses of intra-Acb amphetamine were able to prolong responding within the session (resulting in an increased break point) on day 3 of REMSD while only the highest dose was sufficient following 5 days of REMSD. These data suggest that decreased motivation for food reward caused by REMSD may result from a suppression of dopamine function in the Acb. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Hidden and Neglected: Food Poverty in the Global North - The Case of Germany.

    Science.gov (United States)

    Pfeiffer, Sabine; Oestreicher, Elke; Ritter, Tobias

    2016-01-01

    Although still a powerful economy, Germany faces rising income inequality and food insecurity. Quantitative data show that nutritional poverty in Germany has become a fact, especially for social welfare recipients. This contribution gives an overview and discusses the limits of results from different data sources, such as German food surveys, and addresses how affected population groups are systematically underrepresented. To give a more thorough impression of food insecurity in Germany, the article compares nutritional consumption data from the Statistics on Income and Living Conditions/Eurostat survey for Germany, the members of the European Union 27 (EU27), and Greece. The figures for Germans with incomes below 60% of the median equivalised income who cannot afford one proper meal every second day are worse than those in the remaining EU27 member nations, and the figures for their children are not so far from the figures for crisis-stricken Greece. As eating is not only about nutrition but also a means of social activity, we consider the ability to eat and drink with friends an issue of alimentary participation. The percentages of Germans who cannot afford a drink or meal with others at least once a month is very high compared to the rates of the remaining EU27 member nations and Greece. The provided quantitative figures prove that we see serious signs of food poverty in portions of Germany, despite its comparatively strong economy. Data from hundreds of qualitative interviews describing how people stricken by food insecurity try to cope with the situation complement these results. Such data are very important, as governments widely underestimate the problem and leave it to be dealt with by food banks as the only institutional solution. © 2016 S. Karger AG, Basel.

  4. Intra-accumbens baclofen, but not muscimol, increases second order instrumental responding for food reward in rats.

    Directory of Open Access Journals (Sweden)

    Kim G T Pulman

    Full Text Available Stimulation of either GABA(A or GABA(B receptors within the nucleus accumbens shell strongly enhances food intake in rats. However the effects of subtype-selective stimulation of GABA receptors on instrumental responses for food reward are less well characterized. Here we contrast the effects of the GABA(A receptor agonist muscimol and GABA(B receptor agonist baclofen on instrumental responding for food using a second order reinforcement schedule. Bilateral intra-accumbens administration of baclofen (220-440 pmol stimulated responding but a higher dose (660 pmol induced stereotyped oral behaviour that interfered with responding. Baclofen (220-660 pmol also stimulated intake of freely available chow. Muscimol (220-660 pmol was without effect on responding for food on this schedule but did stimulate intake of freely available chow. Unilateral administration of either baclofen or muscimol (220 pmol induced similar patterns of c-fos immunoreactivity in several hypothalamic sites but differed in its induction in the central nucleus of the amygdala. We conclude that stimulation of GABA(A or GABA(B receptors in the nucleus accumbens shell of rats produces clearly distinguishable effects on operant responding for food.

  5. Intra-accumbens baclofen, but not muscimol, increases second order instrumental responding for food reward in rats.

    Science.gov (United States)

    Pulman, Kim G T; Somerville, Elizabeth M; Clifton, Peter G

    2012-01-01

    Stimulation of either GABA(A) or GABA(B) receptors within the nucleus accumbens shell strongly enhances food intake in rats. However the effects of subtype-selective stimulation of GABA receptors on instrumental responses for food reward are less well characterized. Here we contrast the effects of the GABA(A) receptor agonist muscimol and GABA(B) receptor agonist baclofen on instrumental responding for food using a second order reinforcement schedule. Bilateral intra-accumbens administration of baclofen (220-440 pmol) stimulated responding but a higher dose (660 pmol) induced stereotyped oral behaviour that interfered with responding. Baclofen (220-660 pmol) also stimulated intake of freely available chow. Muscimol (220-660 pmol) was without effect on responding for food on this schedule but did stimulate intake of freely available chow. Unilateral administration of either baclofen or muscimol (220 pmol) induced similar patterns of c-fos immunoreactivity in several hypothalamic sites but differed in its induction in the central nucleus of the amygdala. We conclude that stimulation of GABA(A) or GABA(B) receptors in the nucleus accumbens shell of rats produces clearly distinguishable effects on operant responding for food.

  6. Genetic predisposition to obesity affects behavioural traits including food reward and anxiety-like behaviour in rats.

    Science.gov (United States)

    Vogel, Heike; Kraemer, Maria; Rabasa, Cristina; Askevik, Kaisa; Adan, Roger A H; Dickson, Suzanne L

    2017-06-15

    Here we sought to define behavioural traits linked to anxiety, reward, and exploration in different strains of rats commonly used in obesity research. We hypothesized that genetic variance may contribute not only to their metabolic phenotype (that is well documented) but also to the expression of these behavioural traits. Rat strains that differ in their susceptibility to develop an obese phenotype (Sprague-Dawley, Obese Prone, Obese Resistant, and Zucker rats) were exposed to a number of behavioural tests starting at the age of 8 weeks. We found a similar phenotype in the obesity susceptible models, Obese Prone and Zucker rats, with a lower locomotor activity, exploratory activity, and higher level of anxiety-like behaviour in comparison to the leaner Obese Resistant strain. We did not find evidence that rat strains with a genetic predisposition to obesity differed in their ability to experience reward from chocolate (in a condition place preference task). However, Zucker rats show higher motivated behaviour for sucrose compared to Obese Resistant rats when the effort required to obtain palatable food is relatively low. Together our data demonstrate that rat strains that differ in their genetic predisposition to develop obesity also differ in their performance in behavioural tests linked to anxiety, exploration, and reward and that these differences are independent of body weight. We conclude that genetic variations which determine body weight and the aforementioned behaviours co-exist but that future studies are required to identify whether (and which) common genes are involved. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  7. The mediating role of child self-regulation of eating in the relationship between parental use of food as a reward and child emotional overeating.

    Science.gov (United States)

    Powell, Elisabeth M; Frankel, Leslie A; Hernandez, Daphne C

    2017-06-01

    Emotional eating, or eating in response to negative emotions rather than internal hunger cues, has been related to many maladaptive eating patterns that contribute to weight gain and obesity. The parent feeding practice of use of food as a reward is positively associated with children emotionally overeating, yet, little is known as to the potential behavioral mechanism linking these behaviors. The current study examined the mediating role of child self-regulation of eating in the relationship between parental use of food as a reward and child emotional overeating. Parents of preschool aged children (n = 254) completed online questionnaires targeting parent feeding practices, child eating behaviors, and child self-regulation in eating. Mediation was assessed with Hayes' PROCESS macros in SPSS. Results demonstrated that the relationship between parental use of food as a reward and child emotional overeating was partially mediated by child self-regulation in eating, even after controlling for parent and child gender, household income, and race/ethnicity. In summary, parental use of food as a reward leads to children's diminished ability to regulate intake, which then leads to increased emotional over eating. Results of this study have implications for both the prevention of disordered eating behaviors and childhood obesity prevention programs, suggesting the need to assist children in learning how to self-regulate in the presence of food. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Human protein status modulates brain reward responses to food cues1–3

    NARCIS (Netherlands)

    Griffioen-Roose, S.; Smeets, P.A.M.; Heuvel, van den E.M.; Boesveldt, S.; Finlayson, G.; Graaf, de C.

    2014-01-01

    Background: Protein is indispensable in the human diet, and its intake appears tightly regulated. The role of sensory attributes of foods in protein intake regulation is far from clear. Objective: We investigated the effect of human protein status on neural responses to different food cues with the

  9. Point-of-Purchase Labels and Reward Cards Improve Sales of Healthy Foods in University Dining Halls.

    Science.gov (United States)

    Biden, Catherine R; Matthews, June I; Laframboise, Natalie A; Zok, Anne; Dworatzek, Paula D N; Seabrook, Jamie A

    2018-06-12

    To compare sales of Food Resources and Education for Student Health (FRESH) Approved versus non-FRESH Approved menu cycle items pre- and postimplementation of the FRESH program. Sales data from 2011-2015 of FRESH Approved versus non-FRESH Approved menu items were analyzed. Fruit and milk items sold, net sales, and the cost of free fruit and milk redeemed through the FRESH Reward Card (FRC) program, were also analyzed. FRESH Approved items sold more often than non-FRESH Approved items in the latter 2 years (P = 0.01). Prices of FRESH Approved menu items were significantly lower than non-FRESH Approved items for all years (e.g., $1.52 ± $0.94 vs $2.21 ± $1.02 per serving in 2014-2015; P < 0.001). Across all FRESH implementation years, FRESH Approved menu items were found more often on the 6-week menu (P < 0.05). The number of fruit items sold increased from a baseline of 143 052 to 170 954, and net sales increased from $135 450 to $154 248 after 3 years of the FRC implementation. FRESH Approved items were less expensive, available more often, and had higher sales. The FRC increased net fruit sales despite the cost of free fruit. Highlighting and reducing the cost of healthy foods are promising practices to improve campus food environments.

  10. The drive to eat: comparisons and distinctions between mechanisms of food reward and drug addiction.

    Science.gov (United States)

    DiLeone, Ralph J; Taylor, Jane R; Picciotto, Marina R

    2012-10-01

    The growing rates of obesity have prompted comparisons between the uncontrolled intake of food and drugs; however, an evaluation of the equivalence of food- and drug-related behaviors requires a thorough understanding of the underlying neural circuits driving each behavior. Although it has been attractive to borrow neurobiological concepts from addiction to explore compulsive food seeking, a more integrated model is needed to understand how food and drugs differ in their ability to drive behavior. In this Review, we will examine the commonalities and differences in the systems-level and behavioral responses to food and to drugs of abuse, with the goal of identifying areas of research that would address gaps in our understanding and ultimately identify new treatments for obesity or drug addiction.

  11. Low Fat Loss Response after Medium-Term Supervised Exercise in Obese Is Associated with Exercise-Induced Increase in Food Reward

    Directory of Open Access Journals (Sweden)

    Graham Finlayson

    2011-01-01

    Full Text Available Objective. To examine exercise-induced changes in the reward value of food during medium-term supervised exercise in obese individuals. Subjects/Methods. The study was a 12-week supervised exercise intervention prescribed to expend 500 kcal/day, 5 d/week. 34 sedentary obese males and females were identified as responders (R or non-responders (NR to the intervention according to changes in body composition relative to measured energy expended during exercise. Food reward (ratings of liking and wanting, and relative preference by forced choice pairs for an array of food images was assessed before and after an acute exercise bout. Results. 20 responders and 14 non-responders were identified. R lost 5.2 kg ± 2.4 of total fat mass and NR lost 1.7 kg ± 1.4. After acute exercise, liking for all foods increased in NR compared to no change in R. Furthermore, NR showed an increase in wanting and relative preference for high-fat sweet foods. These differences were independent of 12-weeks regular exercise and weight loss. Conclusion. Individuals who showed an immediate post-exercise increase in liking and increased wanting and preference for high-fat sweet foods displayed a smaller reduction in fat mass with exercise. For some individuals, exercise increases the reward value of food and diminishes the impact of exercise on fat loss.

  12. Anticipatory and foraging behaviors in response to palatable food reward in chickens: Effects of dopamine D2 receptor blockade and domestication

    NARCIS (Netherlands)

    Moe, R.O.; Nordgreen, J.; Janczak, A.M.; Bakken, M.; Spruijt, Berry; Jensen, P.

    2014-01-01

    Behaviors associated with anticipation and search for palatable food may provide information about dopaminergic reward processes and positive motivational affect in animals. The overall aim was to investigate the involvement of dopamine signaling in the regulation of cue-induced anticipation and

  13. Hidden Liquidity

    OpenAIRE

    Cebiroglu, Gökhan; Horst, Ulrich

    2012-01-01

    We cross-sectionally analyze the presence of aggregated hidden depth and trade volume in the S&P 500 and identify its key determinants. We find that the spread is the main predictor for a stock’s hidden dimension, both in terms of traded and posted liquidity. Our findings moreover suggest that large hidden orders are associated with larger transaction costs, higher price impact and increased volatility. In particular, as large hidden orders fail to attract (latent) liquidity to the market, hi...

  14. Heterogeneity of reward mechanisms.

    Science.gov (United States)

    Lajtha, A; Sershen, H

    2010-06-01

    The finding that many drugs that have abuse potential and other natural stimuli such as food or sexual activity cause similar chemical changes in the brain, an increase in extracellular dopamine (DA) in the shell of the nucleus accumbens (NAccS), indicated some time ago that the reward mechanism is at least very similar for all stimuli and that the mechanism is relatively simple. The presently available information shows that the mechanisms involved are more complex and have multiple elements. Multiple brain regions, multiple receptors, multiple distinct neurons, multiple transmitters, multiple transporters, circuits, peptides, proteins, metabolism of transmitters, and phosphorylation, all participate in reward mechanisms. The system is variable, is changed during development, is sex-dependent, and is influenced by genetic differences. Not all of the elements participate in the reward of all stimuli. Different set of mechanisms are involved in the reward of different drugs of abuse, yet different mechanisms in the reward of natural stimuli such as food or sexual activity; thus there are different systems that distinguish different stimuli. Separate functions of the reward system such as anticipation, evaluation, consummation and identification; all contain function-specific elements. The level of the stimulus also influences the participation of the elements of the reward system, there are possible reactions to even below threshold stimuli, and excessive stimuli can change reward to aversion involving parts of the system. Learning and memory of past reward is an important integral element of reward and addictive behavior. Many of the reward elements are altered by repeated or chronic stimuli, and chronic exposure to one drug is likely to alter the response to another stimulus. To evaluate and identify the reward stimulus thus requires heterogeneity of the reward components in the brain.

  15. Consuming Almonds vs. Isoenergetic Baked Food Does Not Differentially Influence Postprandial Appetite or Neural Reward Responses to Visual Food Stimuli.

    Science.gov (United States)

    Sayer, R Drew; Dhillon, Jaapna; Tamer, Gregory G; Cornier, Marc-Andre; Chen, Ningning; Wright, Amy J; Campbell, Wayne W; Mattes, Richard D

    2017-07-27

    Nuts have high energy and fat contents, but nut intake does not promote weight gain or obesity, which may be partially explained by their proposed high satiety value. The primary aim of this study was to assess the effects of consuming almonds versus a baked food on postprandial appetite and neural responses to visual food stimuli. Twenty-two adults (19 women and 3 men) with a BMI between 25 and 40 kg/m² completed the current study during a 12-week behavioral weight loss intervention. Participants consumed either 28 g of whole, lightly salted roasted almonds or a serving of a baked food with equivalent energy and macronutrient contents in random order on two testing days prior to and at the end of the intervention. Pre- and postprandial appetite ratings and functional magnetic resonance imaging scans were completed on all four testing days. Postprandial hunger, desire to eat, fullness, and neural responses to visual food stimuli were not different following consumption of almonds and the baked food, nor were they influenced by weight loss. These results support energy and macronutrient contents as principal determinants of postprandial appetite and do not support a unique satiety effect of almonds independent of these variables.

  16. Effect of BMI and binge eating on food reward and energy intake: further evidence for a binge eating subtype of obesity.

    Science.gov (United States)

    Dalton, Michelle; Blundell, John; Finlayson, Graham

    2013-01-01

    The psychological characteristics of binge eating have been proposed as a phenotype to further understanding of overconsumption and susceptibility to obesity. This study examined the influence of trait binge eating in lean and overweight or obese women on appetite, food reward and energy intake. 25 lean and 25 overweight or obese women were categorised as either 'binge type' or 'non-binge type' based on their scores on the Binge Eating Scale. Food reward and food intake were assessed in fasted and fed conditions. Overweight or obese binge types (O-B) consumed more energy than overweight or obese non-binge types (O-NB) and lean binge (L-B) and non-binge types (L-NB). Both L-B and O-B exhibited greater preference for sweet foods. In O-NB, L-B and L-NB, lower liking and wanting for sweet foods was exhibited in the fed condition compared to the fasted condition. However, in O-B wanting for sweet foods was greater when they were fed compared to when they were in a fasted state. These findings provide further support for trait binge eating as a hedonic subtype of obesity. Binge types were characterised by greater intake of high-fat sweet foods and increased wanting for these foods when satiated. Additionally, these findings highlight the potential for separation in liking and wanting for food as a marker of susceptibility to overeat.

  17. Maternal “junk-food” feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring

    Science.gov (United States)

    Ong, Z. Y.; Muhlhausler, B. S.

    2011-01-01

    Individuals exposed to high-fat, high-sugar diets before birth have an increased risk of obesity in later life. Recent studies have shown that these offspring exhibit increased preference for fat, leading to suggestions that perinatal exposure to high-fat, high-sugar foods results in permanent changes within the central reward system that increase the subsequent drive to overconsume palatable foods. The present study has determined the effect of a maternal “junk-food” diet on the expression of key components of the mesolimbic reward pathway in the offspring of rat dams at 6 wk and 3 mo of age. We show that offspring of junk-food-fed (JF) dams exhibit higher fat intake from weaning until at least 3 mo of age (males: 16±0.6 vs. 11±0.8 g/kg/d; females: 19±1.3 vs. 13±0.4 g/kg/d; Pjunk-food intake in postnatal life.—Ong, Z. Y., Muhlhausler, B. S. Maternal “junk-food” feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring. PMID:21427213

  18. Corticostriatal-hypothalamic circuitry and food motivation: integration of energy, action and reward.

    Science.gov (United States)

    Kelley, Ann E; Baldo, Brian A; Pratt, Wayne E; Will, Matthew J

    2005-12-15

    Work over the past decade has supported the idea that discrete aspects of appetitive motivation are differentially mediated by separate but interacting neurochemical systems within the nucleus accumbens (Acb). We review herein a series of studies in rats comparing the effects of manipulating Acb amino acid, opioid, acetylcholine, and dopamine systems on tests of free-feeding and food-reinforced operant responding. Results from our laboratory and in the literature support three general conclusions: (1) GABA output neurons localized exclusively within the Acb shell directly influence hypothalamic effector mechanisms for feeding motor patterns, but do not participate in the execution of more complex food-seeking strategies; (2) enkephalinergic neurons distributed throughout the Acb and caudate-putamen mediate the hedonic impact of palatable (high sugar/fat) foods, and these neurons are under modulatory control by striatal cholinergic interneurons; and (3) dopamine transmission in the Acb governs general motoric and arousal processes related to response selection and invigoration, as well as motor learning-related plasticity. These dissociations may reflect the manner in which these neurochemical systems differentially access pallido-thalamo-cortical loops reaching the voluntary motor system (in the case of opioids and dopamine), versus more restricted efferent connections to hypothalamic motor/autonomic control columns (in the case of Acb shell GABA and glutamate systems). Moreover, we hypothesize that while these systems work in tandem to coordinate the anticipatory and consummatory phases of feeding with hypothalamic energy-sensing substrates, the striatal opioid network evolved a specialized capacity to promote overeating of energy-dense foods beyond acute homeostatic needs, to ensure an energy reserve for potential future famine.

  19. Neural Processing of Calories in Brain Reward Areas Can be Modulated by Reward Sensitivity

    NARCIS (Netherlands)

    van Rijn, Inge; Griffioen-Roose, Sanne; de Graaf, Cees; Smeets, Paul A M

    A food's reward value is dependent on its caloric content. Furthermore, a food's acute reward value also depends on hunger state. The drive to obtain rewards (reward sensitivity), however, differs between individuals. Here, we assessed the association between brain responses to calories in the mouth

  20. A role for the endocannabinoid 2-arachidonoyl-sn-glycerol for social and high-fat food reward in male mice.

    Science.gov (United States)

    Wei, Don; Lee, DaYeon; Li, Dandan; Daglian, Jennifer; Jung, Kwang-Mook; Piomelli, Daniele

    2016-05-01

    The endocannabinoid system is an important modulator of brain reward signaling. Investigations have focused on cannabinoid (CB1) receptors, because dissection of specific contributions of individual endocannabinoids has been limited by the available toolset. While we recently described an important role for the endocannabinoid anandamide in the regulation of social reward, it remains to be determined whether the other major endocannabinoid, 2-arachidonoyl-sn-glycerol (2-AG), serves a similar or different function. To study the role of 2-AG in natural reward, we used a transgenic mouse model (MGL-Tg mice) in which forebrain 2-AG levels are selectively reduced. We complemented behavioral analysis with measurements of brain 2-AG levels. We tested male MGL-Tg mice in conditioned place preference (CPP) tasks for high-fat food, social contact, and cocaine. We measured 2-AG content in the brain regions of interest by liquid chromatography/mass spectrometry. Male MGL-Tg mice are impaired in developing CPP for high-fat food and social interaction, but do develop CPP for cocaine. Furthermore, compared to isolated mice, levels of 2-AG in socially stimulated wild-type mice are higher in the nucleus accumbens and ventral hippocampus (183 and 140 % of controls, respectively), but unchanged in the medial prefrontal cortex. The results suggest that reducing 2-AG-mediated endocannabinoid signaling impairs social and high-fat food reward in male mice, and that social stimulation mobilizes 2-AG in key brain regions implicated in the control of motivated behavior. The time course of this response differentiates 2-AG from anandamide, whose role in mediating social reward was previously documented.

  1. Application of fMRI to obesity research: differences in reward pathway activation measured with fMRI BOLD during visual presentation of high and low calorie foods

    Science.gov (United States)

    Tsao, Sinchai; Adam, Tanja C.; Goran, Michael I.; Singh, Manbir

    2012-03-01

    The factors behind the neural mechanisms that motivate food choice and obesity are not well known. Furthermore, it is not known when these neural mechanisms develop and how they are influenced by both genetic and environmental factors. This study uses fMRI together with clinical data to shed light on the aforementioned questions by investigating how appetite-related activation in the brain changes with low versus high caloric foods in pre-pubescent girls. Previous studies have shown that obese adults have less striatal D2 receptors and thus reduced Dopamine (DA) signaling leading to the reward-deficit theory of obesity. However, overeating in itself reduces D2 receptor density, D2 sensitivity and thus reward sensitivity. The results of this study will show how early these neural mechanisms develop and what effect the drastic endocrinological changes during puberty has on these mechanisms. Our preliminary results showed increased activations in the Putamen, Insula, Thalamus and Hippocampus when looking at activations where High Calorie > Low Calorie. When comparing High Calorie > Control and Low Calorie > Control, the High > Control test showed increased significant activation in the frontal lobe. The Low > Control also yielded significant activation in the Left and Right Fusiform Gyrus, which did not appear in the High > Control test. These results indicate that the reward pathway activations previously shown in post-puberty and adults are present in pre-pubescent teens. These results may suggest that some of the preferential neural mechanisms of reward are already present pre-puberty.

  2. Behavioral measures of risk tasking, sensation seeking and sensitivity to reward may reflect different motivations for spicy food liking and consumption.

    Science.gov (United States)

    Byrnes, Nadia K; Hayes, John E

    2016-08-01

    Based on work a quarter century ago, it is widely accepted personality traits like sensation seeking are related to the enjoyment and intake of spicy foods; however, data supporting this belief is actually quite limited. Recently, we reported strong to moderate correlations between remembered spicy food liking and two personality traits measured with validated questionnaires. Here, participants consumed capsaicin-containing strawberry jelly to generate acute estimates of spicy food liking. Additionally, we used a laboratory-based behavioral measure of risk taking (the mobile Balloon Analogue Risk Task; mBART) to complement a range of validated self-report measures of risk-related personality traits. Present data confirm Sensation Seeking correlates with overall spicy meal liking and liking of the burn of a spicy meal, and extends prior findings by showing novel correlations with the liking of sampled stimuli. Other personality measures, including Sensitivity to Punishment (SP), Sensitivity to Reward (SR), and the Impulsivity and Risk Taking subscales of the DSM5 Personality Inventory (PID-5) did not show significant relationships with liking of spicy foods, either sampled or remembered. Our behavioral risk taking measure, the mBART, also failed to show a relationship with remembered or sampled liking. However, significant relationships were observed between reported intake of spicy foods and Sensitivity to Reward, and the Risk Taking subscale of the PID-5 (PID5-RT). Based on the observed patterns among various personality measures, and spicy food liking and intake, we propose that personality measures may exert their influence on intake of spicy food via different mechanisms. We also speculate that Sensation Seeking may reflect motivations for consuming spicy foods that are more intrinsic, while the motivations for eating spicy foods measured by SR and PID5-RT may be more extrinsic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. School-based intervention with children. Peer-modeling, reward and repeated exposure reduce food neophobia and increase liking of fruits and vegetables.

    Science.gov (United States)

    Laureati, Monica; Bergamaschi, Valentina; Pagliarini, Ella

    2014-12-01

    This study investigated the effectiveness of the 'Food Dudes' school-based intervention consisting of rewards, peer-modeling and food exposure on food neophobia and the liking of fruits and vegetables (FV) in a large cohort of children. Five-hundred sixty children recruited from three schools were assigned to the experimental or control group. For 16 days, children in the experimental group watched motivational videos, were read letters to encourage them to eat FV and received a small reward for eating one portion of both a fruit and a vegetable. The control group was only provided with FV for the same time period. Food neophobia and liking were measured in both groups of children before and after the intervention, and a follow-up measurement was carried out 6 months later. The intervention was effective in reducing food neophobia and, most importantly, a persistent effect was observed 6 months after the intervention as children of the experimental group showed significantly lower neophobia scores than the control group. Additionally, the program was effective in increasing liking for both FV; however, this effect was maintained only for fruit after 6 months. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Beyond Rewards

    Science.gov (United States)

    Hall, Philip S.

    2009-01-01

    Using rewards to impact students' behavior has long been common practice. However, using reward systems to enhance student learning conveniently masks the larger and admittedly more difficult task of finding and implementing the structure and techniques that children with special needs require to learn. More important, rewarding the child for good…

  5. Addictive drugs and brain stimulation reward.

    Science.gov (United States)

    Wise, R A

    1996-01-01

    Direct electrical or chemical stimulation of specific brain regions can establish response habits similar to those established by natural rewards such as food or sexual contact. Cocaine, mu and delta opiates, nicotine, phencyclidine, and cannabis each have actions that summate with rewarding electrical stimulation of the medial forebrain bundle (MFB). The reward-potentiating effects of amphetamine and opiates are associated with central sites of action where these drugs also have their direct rewarding effects, suggesting common mechanisms for drug reward per se and for drug potentiation of brain stimulation reward. The central sites at which these and perhaps other drugs of abuse potentiate brain stimulation reward and are rewarding in their own right are consistent with the hypothesis that the laboratory reward of brain stimulation and the pharmacological rewards of addictive drugs are habit forming because they act in the brain circuits that subserve more natural and biologically significant rewards.

  6. The public understanding of nanotechnology in the food domain: the hidden role of views on science, technology, and nature.

    Science.gov (United States)

    Vandermoere, Frederic; Blanchemanche, Sandrine; Bieberstein, Andrea; Marette, Stephan; Roosen, Jutta

    2011-03-01

    In spite of great expectations about the potential of nanotechnology, this study shows that people are rather ambiguous and pessimistic about nanotechnology applications in the food domain. Our findings are drawn from a survey of public perceptions about nanotechnology food and nanotechnology food packaging (N = 752). Multinomial logistic regression analyses further reveal that knowledge about food risks and nanotechnology significantly influences people's views about nanotechnology food packaging. However, knowledge variables were unrelated to support for nanofood, suggesting that an increase in people's knowledge might not be sufficient to bridge the gap between the excitement some business leaders in the food sector have and the restraint of the public. Additionally, opposition to nanofood was not related to the use of heuristics but to trust in governmental agencies. Furthermore, the results indicate that public perceptions of nanoscience in the food domain significantly relate to views on science, technology, and nature.

  7. Rewards and Performance Incentives.

    Science.gov (United States)

    Zigon, Jack

    1994-01-01

    Discusses rewards and performance incentives for employees, including types of rewards; how rewards help in managing; dysfunctional awards; selecting the right reward; how to find rewards that fit; and delivering rewards effectively. Examples are included. (three references) (LRW)

  8. Dopamine efflux in the nucleus accumbens during within-session extinction, outcome-dependent, and habit-based instrumental responding for food reward.

    Science.gov (United States)

    Ahn, Soyon; Phillips, Anthony G

    2007-04-01

    Dopamine (DA) activity in the nucleus accumbens (NAc) is related to the general motivational effects of rewarding stimuli. Dickinson and colleagues have shown that initial acquisition of instrumental responding reflects action-outcome relationships based on instrumental incentive learning, which establishes the value of an outcome. Given that the sensitivity of responding to outcome devaluation is not affected by NAc lesions, it is unlikely that incentive learning during the action-outcome phase is mediated by DA activity in the NAc. DA efflux in the NAc after limited and extended training was compared on the assumption that comparable changes would be observed during both action-outcome- and habit-based phases of instrumental responding for food. This study also tested the hypothesis that increase in NAc DA activity is correlated with instrumental responding during extinction maintained by a conditioned stimulus paired with food. Rats were trained to lever press for food (random-interval 30 s schedule). On the 5th and 16th day of training, microdialysis samples were collected from the NAc or mediodorsal striatum (a control site for generalized activity) during instrumental responding in extinction and then for food reward, and analyzed for DA content using high performance liquid chromatography. Increase in DA efflux in the NAc accompanied responding for food pellets on both days 5 and 16, with the magnitude of increase significantly enhanced on day 16. DA efflux was also significantly elevated during responding in extinction only on day 16. These results support a role for NAc DA activity in Pavlovian, but not instrumental, incentive learning.

  9. Naloxone treatment alters gene expression in the mesolimbic reward system in 'junk food' exposed offspring in a sex-specific manner but does not affect food preferences in adulthood.

    Science.gov (United States)

    Gugusheff, J R; Ong, Z Y; Muhlhausler, B S

    2014-06-22

    We have previously reported that the opioid receptor blocker, naloxone, is less effective in reducing palatable food intake in offspring exposed to a maternal cafeteria diet during the perinatal period, implicating a desensitization of the central opioid pathway in the programming of food preferences. The present study aimed to investigate the effect of a maternal cafeteria diet and naloxone treatment on the development of the mesolimbic reward pathway and food choices in adulthood. We measured mRNA expression of key components of the reward pathway (mu-opioid receptor, proenkephalin, tyrosine hydroxylase, D1 and D2 receptors and the dopamine active transporter (DAT)) in the nucleus accumbens (NAc) and ventral tegmental area (VTA) of the offspring of control and cafeteria fed (JF) dams at weaning and after a 10-day naloxone treatment post-weaning and determined food preferences in adulthood in the remaining offspring. Naloxone treatment decreased the expression of DAT by 8.2 fold in female control offspring but increased it by 4.3 fold in female offspring of JF dams relative to the saline-injected reference groups. Proenkephalin mRNA expression was higher in the NAc of female JF offspring compared to controls, independent of naloxone treatment (Pfood preferences in adulthood in either control or JF offspring. These data indicate that prenatal exposure to a cafeteria diet alters the impact of opioid signaling blockade in the early post-weaning period on gene expression in the central reward pathway in a sex specific manner, but that these changes in gene expression do not appear to have any persistent impact on food preferences in adulthood. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Lack of awareness among future medical professionals about the risk of consuming hidden phosphate-containing processed food and drinks.

    Directory of Open Access Journals (Sweden)

    Yoshiko Shutto

    Full Text Available Phosphate toxicity is an important determinant of mortality in patients with chronic kidney disease (CKD, particularly those undergoing hemodialysis treatments. CKD patients are advised to take a low phosphate-containing diet, and are additionally prescribed with phosphate-lowering drugs. Since these patients usually seek guidance from their physicians and nurses for their dietary options, we conducted a survey to determine the levels of awareness regarding the high phosphate content in commercially processed food and drinks among medical and nursing students at the Hirosaki University School of Medicine in Japan. For this survey, 190 medical and nursing students (average age 21.7±3 years were randomly selected, and provided with a list of questions aimed at evaluating their awareness of food and drinks containing artificially added phosphate ingredients. While 98.9% of these students were aware of the presence of sugar in commercially available soda drinks, only 6.9% were aware of the presence of phosphate (phosphoric acid. Similarly, only 11.6% of these students were aware of the presence of phosphate in commercially processed food, such as hamburgers and pizza. Moreover, around two thirds of the surveyed students (67.7% were unaware of the harmful effects of unrestricted consumption of phosphate-containing food and drinks. About 28% of the surveyed students consume such "fast food" once a week, while 40% drink at least 1∼5 cans of soda drinks/week. After realizing the potential long-term risks of consuming excessive phosphate-containing food and drinks, 40.5% of the survey participants considered reducing their phosphate intake by minimizing the consumption of commercially processed "fast food" items and soda drinks. Moreover, another 48.4% of students showed interest in obtaining more information on the negative health effects of consuming excessive amounts of phosphate. This survey emphasizes the need for educational initiative to raise

  11. Stress and reward

    DEFF Research Database (Denmark)

    Chumbley, J R; Hulme, O; Köchli, H

    2014-01-01

    Healthy individuals tend to consume available rewards like food and sex. This tendency is attenuated or amplified in most stress-related psychiatric conditions, so we asked if it depends on endogenous levels of the 'canonical stress hormone' cortisol. We unobtrusively quantified how hard healthy...

  12. Eating tasty foods to cope, enhance reward, socialize or conform: What other psychological characteristics describe each of these motives?

    Science.gov (United States)

    Boggiano, Mary M; Wenger, Lowell E; Burgess, Emilee E; Tatum, Mindy M; Sylvester, Maria D; Morgan, Phillip R; Morse, Kathryn E

    2017-03-01

    Psychological characteristics associated with eating motives of the Palatable Eating Motives Scale (PEMS) were identified in 192 undergraduates. Coping was characterized by greater BMI, emotion-triggered eating, and eating concern and also by binge-eating and perceived stress reactivity in females. Reward Enhancement was characterized by greater BMI, anxiety- and depression-eating in females and by anger/frustration-eating in males. Conformity was strongly characterized by binge-eating and by failure-based stress and all eating disorder traits in females and by anger/frustration- and anxiety-eating in males. The sex-divergent patterns of these traits across PEMS motives highlight the heterogeneity of hedonic eating. The traits may also be maintaining the motives, hence adresseing them should improve treatments for obesity, binge-eating, and foster healthier coping, reward, and psychosocial interactions.

  13. Association of the melanocortin 4 receptor gene rs17782313 polymorphism with rewarding value of food and eating behavior in Chilean children.

    Science.gov (United States)

    Obregón, A M; Oyarce, K; Santos, J L; Valladares, M; Goldfield, G

    2017-02-01

    Studies conducted in monozygotic and dizygotic twins have established a strong genetic component in eating behavior. Rare mutations and common variants of the melanocortin 4 receptor (MC4R) gene have been linked to obesity and eating behavior scores. However, few studies have assessed common variants in MC4R gene with the rewarding value of food in children. The objective of the study was to evaluate the association between the MC4R rs17782313 polymorphism with homeostatic and non-homeostatic eating behavior patterns in Chileans children. This is a cross-sectional study in 258 Chilean children (44 % female, 8-14 years old) showing a wide variation in BMI. Anthropometric measurements (weight, height, Z-score of BMI and waist circumference) were performed by standard procedures. Eating behavior was assessed using the Eating in Absence of Hunger Questionnaire (EAHQ), the Child Eating Behavior Questionnaire (CEBQ), the Three-Factor Eating Questionnaire (TFEQ), and the Food Reinforcement Value Questionnaire (FRVQ). Genotype of the rs17782313 nearby MC4R was determined by a Taqman assay. Association of the rs17782313 C allele with eating behavior was assessed using non-parametric tests. We found that children carrying the CC genotype have higher scores of food responsiveness (p value = 0.02). In obese girls, carriers of the C allele showed lower scores of satiety responsiveness (p value = 0.02) and higher scores of uncontrolled eating (p value = 0.01). Obese boys carrying the C allele showed lower rewarding value of food in relation to non-carriers. The rs17782313 C allele is associated with eating behavior traits that may predispose obese children to increased energy intake and obesity.

  14. Social reward shapes attentional biases.

    Science.gov (United States)

    Anderson, Brian A

    2016-01-01

    Paying attention to stimuli that predict a reward outcome is important for an organism to survive and thrive. When visual stimuli are associated with tangible, extrinsic rewards such as money or food, these stimuli acquire high attentional priority and come to automatically capture attention. In humans and other primates, however, many behaviors are not motivated directly by such extrinsic rewards, but rather by the social feedback that results from performing those behaviors. In the present study, I examine whether positive social feedback can similarly influence attentional bias. The results show that stimuli previously associated with a high probability of positive social feedback elicit value-driven attentional capture, much like stimuli associated with extrinsic rewards. Unlike with extrinsic rewards, however, such stimuli also influence task-specific motivation. My findings offer a potential mechanism by which social reward shapes the information that we prioritize when perceiving the world around us.

  15. Low doses of neonicotinoid pesticides in food rewards impair short-term olfactory memory in foraging-age honeybees.

    Science.gov (United States)

    Wright, Geraldine A; Softley, Samantha; Earnshaw, Helen

    2015-10-19

    Neonicotinoids are often applied as systemic seed treatments to crops and have reported negative impact on pollinators when they appear in floral nectar and pollen. Recently, we found that bees in a two-choice assay prefer to consume solutions containing field-relevant doses of the neonicotinoid pesticides, imidacloprid (IMD) and thiamethoxam (TMX), to sucrose alone. This suggests that neonicotinoids enhance the rewarding properties of sucrose and that low, acute doses could improve learning and memory in bees. To test this, we trained foraging-age honeybees to learn to associate floral scent with a reward containing nectar-relevant concentrations of IMD and TMX and tested their short (STM) and long-term (LTM) olfactory memories. Contrary to our predictions, we found that none of the solutions enhanced the rate of olfactory learning and some of them impaired it. In particular, the effect of 10 nM IMD was observed by the second conditioning trial and persisted 24 h later. In most other groups, exposure to IMD and TMX affected STM but not LTM. Our data show that negative impacts of low doses of IMD and TMX do not require long-term exposure and suggest that impacts of neonicotinoids on olfaction are greater than their effects on rewarding memories.

  16. Incentive theory: IV. Magnitude of reward

    OpenAIRE

    Killeen, Peter R.

    1985-01-01

    Incentive theory is successfully applied to data from experiments in which the amount of food reward is varied. This is accomplished by assuming that incentive value is a negatively accelerated function of reward duration. The interaction of the magnitude of a reward with its delay is confirmed, and the causes and implications of this interaction are discussed.

  17. Hidden loss

    DEFF Research Database (Denmark)

    Kieffer-Kristensen, Rikke; Johansen, Karen Lise Gaardsvig

    2013-01-01

    to participate. RESULTS: All children were affected by their parents' ABI and the altered family situation. The children's expressions led the authors to identify six themes, including fear of losing the parent, distress and estrangement, chores and responsibilities, hidden loss, coping and support. The main......PRIMARY OBJECTIVE: The purpose of this study was to listen to and learn from children showing high levels of post-traumatic stress symptoms after parental acquired brain injury (ABI), in order to achieve an in-depth understanding of the difficulties the children face in their everyday lives...... finding indicates that the children experienced numerous losses, many of which were often suppressed or neglected by the children to protect the ill parents. CONCLUSIONS: The findings indicated that the children seemed to make a special effort to hide their feelings of loss and grief in order to protect...

  18. Why is obesity such a problem in the 21st century? The intersection of palatable food, cues and reward pathways, stress, and cognition.

    Science.gov (United States)

    Morris, Margaret J; Beilharz, Jessica E; Maniam, Jayanthi; Reichelt, Amy C; Westbrook, R Frederick

    2015-11-01

    Changes in food composition and availability have contributed to the dramatic increase in obesity over the past 30-40 years in developed and, increasingly, in developing countries. The brain plays a critical role in regulating energy balance. Some human studies have demonstrated increased preference for high fat and high sugar foods in people reporting greater stress exposure. We have examined neurochemical changes in the brain in rodent models during the development of obesity, including the impact of obesity on cognition, reward neurocircuitry and stress responsiveness. Using supermarket foods high in fat and sugar, we showed that such a diet leads to changes in neurotransmitters involved in the hedonic appraisal of foods, indicative of an addiction-like capacity of foods high in fat and/or sugar. Importantly, withdrawal of the palatable diet led to a stress-like response. Furthermore, access to this palatable diet attenuated the physiological effects of acute stress (restraint), indicating that it could act as a comfort food. In more chronic studies, the diet also attenuated anxiety-like behavior in rats exposed to stress (maternal separation) early in life, but these rats may suffer greater metabolic harm than rats exposed to the early life stressor but not provided with the palatable diet. Impairments in cognitive function have been associated with obesity in both people and rodents. However, as little as 1 week of exposure to a high fat, high sugar diet selectively impaired place but not object recognition memory in the rat. Excess sugar alone had similar effects, and both diets were linked to increased inflammatory markers in the hippocampus, a critical region involved in memory. Obesity-related inflammatory changes have been found in the human brain. Ongoing work examines interventions to prevent or reverse diet-induced cognitive impairments. These data have implications for minimizing harm caused by unhealthy eating. Copyright © 2014 Elsevier Ltd. All

  19. Bad news: an experimental study on the informational effects of rewards

    NARCIS (Netherlands)

    Bremzen, A.; Khokhlova, E.; Suvorov, A.; van de Ven, J.

    2015-01-01

    Psychologists and economists have argued that rewards often have hidden costs. One possible reason is that the principal may have incentives to offer higher rewards when she knows the task is difficult. Our experiment tests if high rewards embody such bad news and if this is correctly perceived by

  20. Increased depression-like behaviors with dysfunctions in the stress axis and the reward center by free access to highly palatable food.

    Science.gov (United States)

    Park, E; Kim, J Y; Lee, J-H; Jahng, J W

    2014-03-14

    This study was conducted to examine the behavioral consequences of unlimited consumption of highly palatable food (HPF) and investigate its underlying neural mechanisms. Male Sprague-Dawley rats had free access to chocolate cookie rich in fat (HPF) in addition to ad libitum chow and the control group received chow only. Rats were subjected to behavioral tests during the 2nd week of food condition; i.e. ambulatory activity test on the 8th, elevated plus maze test (EPM) on the 10th and forced swim test (FST) on the 14th day of food condition. After 8 days of food condition, another group of rats were placed in a restraint box and tail bloods were collected at 0, 20, 60, and 120 time points during 2h of restraint period, used for the plasma corticosterone assay. At the end of restraint session, rats were sacrificed and the tissue sections of the nucleus accumbens (NAc) were processed for c-Fos immunohistochemistry. Ambulatory activities and the scores of EPM were not significantly affected by unlimited cookie consumption. However, immobility duration during FST was increased, and swim decreased, in the rats received free cookie access compared with control rats. Stress-induced corticosterone increase was exaggerated in cookie-fed rats, while the stress-induced c-Fos expression in the NAc was blunted, compared to control rats. Results suggest that free access to HPF may lead to the development of depression-like behaviors in rats, likely in relation with dysfunctions in the hypothalamic-pituitary-adrenal axis and the reward center. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Mood, food, and obesity

    OpenAIRE

    Singh, Minati

    2014-01-01

    Food is a potent natural reward and food intake is a complex process. Reward and gratification associated with food consumption leads to dopamine (DA) production, which in turn activates reward and pleasure centers in the brain. An individual will repeatedly eat a particular food to experience this positive feeling of gratification. This type of repetitive behavior of food intake leads to the activation of brain reward pathways that eventually overrides other signals of satiety and hunger. Th...

  2. Attenuation of insulin-evoked responses in brain networks controlling appetite and reward in insulin resistance: the cerebral basis for impaired control of food intake in metabolic syndrome?

    Science.gov (United States)

    Anthony, Karen; Reed, Laurence J; Dunn, Joel T; Bingham, Emma; Hopkins, David; Marsden, Paul K; Amiel, Stephanie A

    2006-11-01

    The rising prevalence of obesity and type 2 diabetes is a global challenge. A possible mechanism linking insulin resistance and weight gain would be attenuation of insulin-evoked responses in brain areas relevant to eating in systemic insulin resistance. We measured brain glucose metabolism, using [(18)F]fluorodeoxyglucose positron emission tomography, in seven insulin-sensitive (homeostasis model assessment of insulin resistance [HOMA-IR] = 1.3) and seven insulin-resistant (HOMA-IR = 6.3) men, during suppression of endogenous insulin by somatostatin, with and without an insulin infusion that elevated insulin to 24.6 +/- 5.2 and 23.2 +/- 5.8 mU/l (P = 0.76), concentrations similar to fasting levels of the resistant subjects and approximately threefold above those of the insulin-sensitive subjects. Insulin-evoked change in global cerebral metabolic rate for glucose was reduced in insulin resistance (+7 vs. +17.4%, P = 0.033). Insulin was associated with increased metabolism in ventral striatum and prefrontal cortex and with decreased metabolism in right amygdala/hippocampus and cerebellar vermis (P reward. Diminishing the link be-tween control of food intake and energy balance may contribute to development of obesity in insulin resistance.

  3. Sociology of Hidden Curriculum

    Directory of Open Access Journals (Sweden)

    Alireza Moradi

    2017-06-01

    Full Text Available This paper reviews the concept of hidden curriculum in the sociological theories and wants to explain sociological aspects of formation of hidden curriculum. The main question concentrates on the theoretical approaches in which hidden curriculum is explained sociologically.For this purpose it was applied qualitative research methodology. The relevant data include various sociological concepts and theories of hidden curriculum collected by the documentary method. The study showed a set of rules, procedures, relationships and social structure of education have decisive role in the formation of hidden curriculum. A hidden curriculum reinforces by existed inequalities among learners (based on their social classes or statues. There is, in fact, a balance between the learner's "knowledge receptions" with their "inequality proportion".The hidden curriculum studies from different major sociological theories such as Functionalism, Marxism and critical theory, Symbolic internationalism and Feminism. According to the functionalist perspective a hidden curriculum has a social function because it transmits social values. Marxists and critical thinkers correlate between hidden curriculum and the totality of social structure. They depicts that curriculum prepares learners for the exploitation in the work markets. Symbolic internationalism rejects absolute hegemony of hidden curriculum on education and looks to the socialization as a result of interaction between learner and instructor. Feminism theory also considers hidden curriculum as a vehicle which legitimates gender stereotypes.

  4. The endocannabinoid system in brain reward processes.

    Science.gov (United States)

    Solinas, M; Goldberg, S R; Piomelli, D

    2008-05-01

    Food, drugs and brain stimulation can serve as strong rewarding stimuli and are all believed to activate common brain circuits that evolved in mammals to favour fitness and survival. For decades, endogenous dopaminergic and opioid systems have been considered the most important systems in mediating brain reward processes. Recent evidence suggests that the endogenous cannabinoid (endocannabinoid) system also has an important role in signalling of rewarding events. First, CB(1) receptors are found in brain areas involved in reward processes, such as the dopaminergic mesolimbic system. Second, activation of CB(1) receptors by plant-derived, synthetic or endogenous CB(1) receptor agonists stimulates dopaminergic neurotransmission, produces rewarding effects and increases rewarding effects of abused drugs and food. Third, pharmacological or genetic blockade of CB(1) receptors prevents activation of dopaminergic neurotransmission by several addictive drugs and reduces rewarding effects of food and these drugs. Fourth, brain levels of the endocannabinoids anandamide and 2-arachidonoylglycerol are altered by activation of reward processes. However, the intrinsic activity of the endocannabinoid system does not appear to play a facilitatory role in brain stimulation reward and some evidence suggests it may even oppose it. The influence of the endocannabinoid system on brain reward processes may depend on the degree of activation of the different brain areas involved and might represent a mechanism for fine-tuning dopaminergic activity. Although involvement of the various components of the endocannabinoid system may differ depending on the type of rewarding event investigated, this system appears to play a major role in modulating reward processes.

  5. Motivation and reward systems

    NARCIS (Netherlands)

    van Eerde, W.; Vodosek, M.; den Hartog, D.N.; McNett, J.M.

    2014-01-01

    Reward systems are identified as one of the human resource management (HRM) practices that may impact motivation. Reward systems may consist of several components, including financial and nonfinancial rewards, in fixed and variable amounts. Reinforcement, expectancy, and equity principles are

  6. Reward Systems in the Brain and Nutrition.

    Science.gov (United States)

    Rolls, Edmund T

    2016-07-17

    The taste cortex in the anterior insula provides separate and combined representations of the taste, temperature, and texture of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex, these sensory inputs are combined by associative learning with olfactory and visual inputs for some neurons, and these neurons encode food reward value in that they respond to food only when hunger is present and in that activations correlate linearly with subjective pleasantness. Cognitive factors, including word-level descriptions and selective attention to affective value, modulate the representation of the reward value of taste, olfactory, and flavor stimuli in the orbitofrontal cortex and a region to which it projects, the anterior cingulate cortex. These food reward representations are important in the control of appetite and food intake. Individual differences in reward representations may contribute to obesity, and there are age-related differences in these reward representations. Implications of how reward systems in the brain operate for understanding, preventing, and treating obesity are described.

  7. POVMs and hidden variables

    International Nuclear Information System (INIS)

    Stairs, Allen

    2007-01-01

    Recent results by Paul Busch and Adan Cabello claim to show that by appealing to POVMs, non-contextual hidden variables can be ruled out in two dimensions. While the results of Busch and Cabello are mathematically correct, interpretive problems render them problematic as no hidden variable proofs

  8. Partially Hidden Markov Models

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Rissanen, Jorma

    1996-01-01

    Partially Hidden Markov Models (PHMM) are introduced. They differ from the ordinary HMM's in that both the transition probabilities of the hidden states and the output probabilities are conditioned on past observations. As an illustration they are applied to black and white image compression where...

  9. Hidden gauge symmetry

    International Nuclear Information System (INIS)

    O'Raifeartaigh, L.

    1979-01-01

    This review describes the principles of hidden gauge symmetry and of its application to the fundamental interactions. The emphasis is on the structure of the theory rather than on the technical details and, in order to emphasise the structure, gauge symmetry and hidden symmetry are first treated as independent phenomena before being combined into a single (hidden gauge symmetric) theory. The main application of the theory is to the weak and electromagnetic interactions of the elementary particles, and although models are used for comparison with experiment and for illustration, emphasis is placed on those features of the application which are model-independent. (author)

  10. Obese individuals with more components of the metabolic syndrome and/or prediabetes demonstrate decreased activation of reward-related brain centers in response to food cues in both the fed and fasting states: a preliminary fMRI study.

    Science.gov (United States)

    Farr, O M; Mantzoros, C S

    2017-03-01

    It remains unknown whether obese individuals with more components of the metabolic syndrome and/or prediabetes demonstrate altered activation of brain centers in response to food cues. We examined obese individuals with prediabetes (n=26) vs obese individuals without prediabetes (n=11) using fMRI. We also performed regression analyses on the basis of the number of MetS components per subject. Obese individuals with prediabetes have decreased activation of the reward-related putamen in the fasting state and decreased activation of the salience- and reward-related insula after eating. Obese individuals with more components of MetS demonstrate decreased activation of the putamen while fasting. All these activations remain significant when corrected for BMI, waist circumference (WC), HbA1c and gender. Decreased activation in the reward-related central nervous system areas among the obese is more pronounced in subjects with prediabetes and MetS. Prospective studies are needed to quantify their contributions to the development of prediabetes/MetS and to study whether they may predispose to the exacerbation of obesity and the development of comorbidities over time.

  11. Fuel not fun: Reinterpreting attenuated brain responses to reward in obesity.

    Science.gov (United States)

    Kroemer, Nils B; Small, Dana M

    2016-08-01

    There is a well-established literature linking obesity to altered dopamine signaling and brain response to food-related stimuli. Neuroimaging studies frequently report enhanced responses in dopaminergic regions during food anticipation and decreased responses during reward receipt. This has been interpreted as reflecting anticipatory "reward surfeit", and consummatory "reward deficiency". In particular, attenuated response in the dorsal striatum to primary food rewards is proposed to reflect anhedonia, which leads to overeating in an attempt to compensate for the reward deficit. In this paper, we propose an alternative view. We consider brain response to food-related stimuli in a reinforcement-learning framework, which can be employed to separate the contributions of reward sensitivity and reward-related learning that are typically entangled in the brain response to reward. Consequently, we posit that decreased striatal responses to milkshake receipt reflect reduced reward-related learning rather than reward deficiency or anhedonia because reduced reward sensitivity would translate uniformly into reduced anticipatory and consummatory responses to reward. By re-conceptualizing reward deficiency as a shift in learning about subjective value of rewards, we attempt to reconcile neuroimaging findings with the putative role of dopamine in effort, energy expenditure and exploration and suggest that attenuated brain responses to energy dense foods reflect the "fuel", not the fun entailed by the reward. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. The hidden universe

    International Nuclear Information System (INIS)

    Disney, M.

    1985-01-01

    Astronomer Disney has followed a somewhat different tack than that of most popular books on cosmology by concentrating on the notion of hidden (as in not directly observable by its own radiation) matter in the universe

  13. Locating Hidden Servers

    National Research Council Canada - National Science Library

    Oeverlier, Lasse; Syverson, Paul F

    2006-01-01

    .... Announced properties include server resistance to distributed DoS. Both the EFF and Reporters Without Borders have issued guides that describe using hidden services via Tor to protect the safety of dissidents as well as to resist censorship...

  14. Food and fuel : a hidden dimension in human nutrition : a study on the relationship between nutrition security and fuelwood availability in Ntcheu District, Malawi

    NARCIS (Netherlands)

    Brouwer, I.D.

    1994-01-01

    Fuelwood is the main source of energy for rural households in developing countries and is predominantly used for food preparation and processing. Due to rapid deforestation, the supply of fuelwood is threatened. Many factors influence household food and nutrition security, but so far the

  15. Hidden charged dark matter

    International Nuclear Information System (INIS)

    Feng, Jonathan L.; Kaplinghat, Manoj; Tu, Huitzu; Yu, Hai-Bo

    2009-01-01

    Can dark matter be stabilized by charge conservation, just as the electron is in the standard model? We examine the possibility that dark matter is hidden, that is, neutral under all standard model gauge interactions, but charged under an exact (\\rm U)(1) gauge symmetry of the hidden sector. Such candidates are predicted in WIMPless models, supersymmetric models in which hidden dark matter has the desired thermal relic density for a wide range of masses. Hidden charged dark matter has many novel properties not shared by neutral dark matter: (1) bound state formation and Sommerfeld-enhanced annihilation after chemical freeze out may reduce its relic density, (2) similar effects greatly enhance dark matter annihilation in protohalos at redshifts of z ∼ 30, (3) Compton scattering off hidden photons delays kinetic decoupling, suppressing small scale structure, and (4) Rutherford scattering makes such dark matter self-interacting and collisional, potentially impacting properties of the Bullet Cluster and the observed morphology of galactic halos. We analyze all of these effects in a WIMPless model in which the hidden sector is a simplified version of the minimal supersymmetric standard model and the dark matter is a hidden sector stau. We find that charged hidden dark matter is viable and consistent with the correct relic density for reasonable model parameters and dark matter masses in the range 1 GeV ∼ X ∼< 10 TeV. At the same time, in the preferred range of parameters, this model predicts cores in the dark matter halos of small galaxies and other halo properties that may be within the reach of future observations. These models therefore provide a viable and well-motivated framework for collisional dark matter with Sommerfeld enhancement, with novel implications for astrophysics and dark matter searches

  16. Hidden in the Middle: Culture, Value and Reward in Bioinformatics

    Science.gov (United States)

    Lewis, Jamie; Bartlett, Andrew; Atkinson, Paul

    2016-01-01

    Bioinformatics--the so-called shotgun marriage between biology and computer science--is an interdiscipline. Despite interdisciplinarity being seen as a virtue, for having the capacity to solve complex problems and foster innovation, it has the potential to place projects and people in anomalous categories. For example, valorised…

  17. Dopamine signaling in reward-related behaviors.

    Science.gov (United States)

    Baik, Ja-Hyun

    2013-01-01

    Dopamine (DA) regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DA mesolimbic neurotransmission have been found to modify behavioral responses to various environmental stimuli associated with reward behaviors. Psychostimulants, drugs of abuse, and natural reward such as food can cause substantial synaptic modifications to the mesolimbic DA system. Recent studies using optogenetics and DREADDs, together with neuron-specific or circuit-specific genetic manipulations have improved our understanding of DA signaling in the reward circuit, and provided a means to identify the neural substrates of complex behaviors such as drug addiction and eating disorders. This review focuses on the role of the DA system in drug addiction and food motivation, with an overview of the role of D1 and D2 receptors in the control of reward-associated behaviors.

  18. Dopamine Signaling in reward-related behaviors

    Directory of Open Access Journals (Sweden)

    Ja-Hyun eBaik

    2013-10-01

    Full Text Available Dopamine (DA regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DAmesolimbic neurotransmission have been found to modify behavioral responses to various environmental stimuli associated with reward behaviors. Psychostimulants, drugs of abuse, and natural rewards such as food can cause substantial synaptic modifications to the mesolimbic DA system. Recent studies using optogenetics and DREADDs, together with neuron-specific or circuit-specific genetic manipulations have improved our understanding of DA signaling in the reward circuit, and provided a means to identify the neural substrates of complex behaviors such as drug addiction and eating disorders. This review focuses on the role of the DA system in drug addiction and food motivation, with an overview of the role of D1 and D2 receptors in the control of reward-associated behaviors.

  19. Endocannabinoid signaling in reward and addiction

    Science.gov (United States)

    Parsons, Loren H.; Hurd, Yasmin L.

    2015-01-01

    Brain endocannabinoid signaling influences the motivation for natural rewards (such as palatable food, sexual activity and social interaction) and modulates the rewarding effects of addictive drugs. Pathological forms of natural and drug-induced reward are associated with dysregulated endocannabinoid signaling that may derive from pre-existing genetic factors or from prolonged drug exposure. Impaired endocannabinoid signaling contributes to dysregulated synaptic plasticity, increased stress responsivity, negative emotional states, and craving that propel addiction. Understanding the contributions of endocannabinoid disruptions to behavioral and physiological traits provides insight into the endocannabinoid influence on addiction vulnerability. PMID:26373473

  20. Dopamine Signaling in reward-related behaviors

    OpenAIRE

    Baik, Ja-Hyun

    2013-01-01

    Dopamine (DA) regulates emotional and motivational behavior through the mesolimbic dopaminergic pathway. Changes in DA mesolimbic neurotransmission have been found to modify behavioral responses to various environmental stimuli associated with reward behaviors. Psychostimulants, drugs of abuse, and natural reward such as food can cause substantial synaptic modifications to the mesolimbic DA system. Recent studies using optogenetics and DREADDs, together with neuron-specific or circuit-specifi...

  1. Food Business Entrepreneurship

    Science.gov (United States)

    Weber, Peter

    Though not a very traditional career path for food scientists, one option is to go into business for yourself by starting a food business. Food business entrepreneurship is a difficult career that entails long work hours, extensive decision making, and tasks that require knowledge beyond food science. However, there is high potential for rewards, including financial rewards, career progression, and personal flexibility.

  2. Hunger and Satiety Gauge Reward Sensitivity

    Directory of Open Access Journals (Sweden)

    Ryan Michael Cassidy

    2017-05-01

    Full Text Available Many of the neurocircuits and hormones known to underlie the sensations of hunger and satiety also substantially alter the activity of the dopaminergic reward system. Much interest lies in the ways that hunger, satiety, and reward tie together, as the epidemic of obesity seems tied to the recent development and mass availability of highly palatable foods. In this review, we will first discuss the basic neurocircuitry of the midbrain and basal forebrain reward system. We will elaborate how several important mediators of hunger—the agouti-related protein neurons of the arcuate nucleus, the lateral hypothalamic nucleus, and ghrelin—enhance the sensitivity of the dopaminergic reward system. Then, we will elaborate how mediators of satiety—the nucleus tractus solitarius, pro-opiomelanocortin neurons of the arcuate nucleus, and its peripheral hormonal influences such as leptin—reduce the reward system sensitivity. We hope to provide a template by which future research may identify the ways in which highly rewarding foods bypass this balanced system to produce excessive food consumption.

  3. Segregated encoding of reward-identity and stimulus-reward associations in human orbitofrontal cortex.

    Science.gov (United States)

    Klein-Flügge, Miriam Cornelia; Barron, Helen Catharine; Brodersen, Kay Henning; Dolan, Raymond J; Behrens, Timothy Edward John

    2013-02-13

    A dominant focus in studies of learning and decision-making is the neural coding of scalar reward value. This emphasis ignores the fact that choices are strongly shaped by a rich representation of potential rewards. Here, using fMRI adaptation, we demonstrate that responses in the human orbitofrontal cortex (OFC) encode a representation of the specific type of food reward predicted by a visual cue. By controlling for value across rewards and by linking each reward with two distinct stimuli, we could test for representations of reward-identity that were independent of associative information. Our results show reward-identity representations in a medial-caudal region of OFC, independent of the associated predictive stimulus. This contrasts with a more rostro-lateral OFC region encoding reward-identity representations tied to the predicate stimulus. This demonstration of adaptation in OFC to reward specific representations opens an avenue for investigation of more complex decision mechanisms that are not immediately accessible in standard analyses, which focus on correlates of average activity.

  4. Search for Hidden Particles

    CERN Multimedia

    Solovev, V

    The SHiP Experiment is a new general-purpose fixed target facility at the SPS to search for hidden particles as predicted by a very large number of recently elaborated models of Hidden Sectors which are capable of accommodating dark matter, neutrino oscillations, and the origin of the full baryon asymmetry in the Universe. Specifically, the experiment is aimed at searching for very weakly interacting long lived particles including Heavy Neutral Leptons - right-handed partners of the active neutrinos; light supersymmetric particles - sgoldstinos, etc.; scalar, axion and vector portals to the hidden sector. The high intensity of the SPS and in particular the large production of charm mesons with the 400 GeV beam allow accessing a wide variety of light long-lived exotic particles of such models and of SUSY. Moreover, the facility is ideally suited to study the interactions of tau neutrinos.

  5. Extinction and renewal of cue-elicited reward-seeking.

    Science.gov (United States)

    Bezzina, Louise; Lee, Jessica C; Lovibond, Peter F; Colagiuri, Ben

    2016-12-01

    Reward cues can contribute to overconsumption of food and drugs and can relapse. The failure of exposure therapies to reduce overconsumption and relapse is generally attributed to the context-specificity of extinction. However, no previous study has examined whether cue-elicited reward-seeking (as opposed to cue-reactivity) is sensitive to context renewal. We tested this possibility in 160 healthy volunteers using a Pavlovian-instrumental transfer (PIT) design involving voluntary responding for a high value natural reward (chocolate). One reward cue underwent Pavlovian extinction in the same (Group AAA) or different context (Group ABA) to all other phases. This cue was compared with a second non-extinguished reward cue and an unpaired control cue. There was a significant overall PIT effect with both reward cues eliciting reward-seeking on test relative to the unpaired cue. Pavlovian extinction substantially reduced this effect, with the extinguished reward cue eliciting less reward-seeking than the non-extinguished reward cue. Most interestingly, extinction of cue-elicited reward-seeking was sensitive to renewal, with extinction less effective for reducing PIT when conducted in a different context. These findings have important implications for extinction-based interventions for reducing maladaptive reward-seeking in practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. An investigation of the impact of total reward packages on employee job satisfaction in a particular fast food industry: a case of McDonald’s, Pakistan

    OpenAIRE

    Santosh, Jaishaal

    2017-01-01

    2017 dissertation for MSc in International Business Management. Selected by academic staff as a good example of a masters level dissertation. Purpose – The purpose of this paper is to investigate the impact of total\\ud reward packages and their components, offered by McDonald’s in Pakistan\\ud to its employees, on employee job satisfaction. The study explored the\\ud factors that influenced the job satisfaction of employees in the sample. The\\ud study also examined the relationship between tota...

  7. Dopamine reward prediction error coding

    OpenAIRE

    Schultz, Wolfram

    2016-01-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards?an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less...

  8. The hidden values

    DEFF Research Database (Denmark)

    Rasmussen, Birgitte; Jensen, Karsten Klint

    “The Hidden Values - Transparency in Decision-Making Processes Dealing with Hazardous Activities”. The report seeks to shed light on what is needed to create a transparent framework for political and administrative decisions on the use of GMOs and chemical products. It is our hope that the report...

  9. Dopamine and Reward: The Anhedonia Hypothesis 30 years on

    OpenAIRE

    Wise, Roy A.

    2008-01-01

    The anhedonia hypothesis – that brain dopamine plays a critical role in the subjective pleasure associated with positive rewards – was intended to draw the attention of psychiatrists to the growing evidence that dopamine plays a critical role in the objective reinforcement and incentive motivation associated with food and water, brain stimulation reward, and psychomotor stimulant and opiate reward. The hypothesis called to attention the apparent paradox that neuroleptics, drugs used to treat ...

  10. Lighting up the brain's reward circuitry.

    Science.gov (United States)

    Lobo, Mary Kay

    2012-07-01

    The brain's reward circuit is critical for mediating natural reward behaviors including food, sex, and social interaction. Drugs of abuse take over this circuit and produce persistent molecular and cellular alterations in the brain regions and their neural circuitry that make up the reward pathway. Recent use of optogenetic technologies has provided novel insights into the functional and molecular role of the circuitry and cell subtypes within these circuits that constitute this pathway. This perspective will address the current and future use of light-activated proteins, including those involved in modulating neuronal activity, cellular signaling, and molecular properties in the neural circuitry mediating rewarding stimuli and maladaptive responses to drugs of abuse. © 2012 New York Academy of Sciences.

  11. The rewarding value of good motor performance in the context of monetary incentives.

    Science.gov (United States)

    Lutz, Kai; Pedroni, Andreas; Nadig, Karin; Luechinger, Roger; Jäncke, Lutz

    2012-07-01

    Whether an agent receives positive task feedback or a monetary reward, neural activity in their striatum increases. In the latter case striatal activity reflects extrinsic reward processing, while in the former, striatal activity reflects the intrinsically rewarding effects of performing well. There can be a "hidden cost of reward", which is a detrimental effect of extrinsic on intrinsic reward value. This raises the question how these two types of reward interact. To address this, we applied a monetary incentive delay task: in all trials participants received feedback depending on their performance. In half of the trials they could additionally receive monetary reward if they performed well. This resulted in high performance trials, which were monetarily rewarded and high performance trials that were not. This made it possible to dissociate the neural correlates of performance feedback from the neural correlates of monetary reward that comes with high performance. Performance feedback alone elicits activation increases in the ventral striatum. This activation increases due to additional monetary reward. Neural response in the dorsal striatum on the other hand is only significantly increased by feedback when a monetary incentive is present. The quality of performance does not significantly influence dorsal striatum activity. In conclusion, our results indicate that the dorsal striatum is primarily sensitive to optional or actually received external rewards, whereas the ventral striatum may be coding intrinsic reward due to positive performance feedback. Thus the ventral striatum is suggested to be involved in the processing of intrinsically motivated behavior. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. A test of the reward-value hypothesis.

    Science.gov (United States)

    Smith, Alexandra E; Dalecki, Stefan J; Crystal, Jonathon D

    2017-03-01

    Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.

  13. "Liking" and "wanting" linked to Reward Deficiency Syndrome (RDS): hypothesizing differential responsivity in brain reward circuitry.

    Science.gov (United States)

    Blum, Kenneth; Gardner, Eliot; Oscar-Berman, Marlene; Gold, Mark

    2012-01-01

    In an attempt to resolve controversy regarding the causal contributions of mesolimbic dopamine (DA) systems to reward, we evaluate the three main competing explanatory categories: "liking,"learning," and "wanting" [1]. That is, DA may mediate (a) the hedonic impact of reward (liking), (b) learned predictions about rewarding effects (learning), or (c) the pursuit of rewards by attributing incentive salience to reward-related stimuli (wanting). We evaluate these hypotheses, especially as they relate to the Reward Deficiency Syndrome (RDS), and we find that the incentive salience or "wanting" hypothesis of DA function is supported by a majority of the evidence. Neuroimaging studies have shown that drugs of abuse, palatable foods, and anticipated behaviors such as sex and gaming affect brain regions involving reward circuitry, and may not be unidirectional. Drugs of abuse enhance DA signaling and sensitize mesolimbic mechanisms that evolved to attribute incentive salience to rewards. Addictive drugs have in common that they are voluntarily selfadministered, they enhance (directly or indirectly) dopaminergic synaptic function in the nucleus accumbens (NAC), and they stimulate the functioning of brain reward circuitry (producing the "high" that drug users seek). Although originally believed simply to encode the set point of hedonic tone, these circuits now are believed to be functionally more complex, also encoding attention, reward expectancy, disconfirmation of reward expectancy, and incentive motivation. Elevated stress levels, together with polymorphisms of dopaminergic genes and other neurotransmitter genetic variants, may have a cumulative effect on vulnerability to addiction. The RDS model of etiology holds very well for a variety of chemical and behavioral addictions.

  14. A Fly's Eye View of Natural and Drug Reward.

    Science.gov (United States)

    Lowenstein, Eve G; Velazquez-Ulloa, Norma A

    2018-01-01

    Animals encounter multiple stimuli each day. Some of these stimuli are innately appetitive or aversive, while others are assigned valence based on experience. Drugs like ethanol can elicit aversion in the short term and attraction in the long term. The reward system encodes the predictive value for different stimuli, mediating anticipation for attractive or punishing stimuli and driving animal behavior to approach or avoid conditioned stimuli. The neurochemistry and neurocircuitry of the reward system is partly evolutionarily conserved. In both vertebrates and invertebrates, including Drosophila melanogaster , dopamine is at the center of a network of neurotransmitters and neuromodulators acting in concert to encode rewards. Behavioral assays in D. melanogaster have become increasingly sophisticated, allowing more direct comparison with mammalian research. Moreover, recent evidence has established the functional modularity of the reward neural circuits in Drosophila . This functional modularity resembles the organization of reward circuits in mammals. The powerful genetic and molecular tools for D. melanogaster allow characterization and manipulation at the single-cell level. These tools are being used to construct a detailed map of the neural circuits mediating specific rewarding stimuli and have allowed for the identification of multiple genes and molecular pathways that mediate the effects of reinforcing stimuli, including their rewarding effects. This report provides an overview of the research on natural and drug reward in D. melanogaster , including natural rewards such as sugar and other food nutrients, and drug rewards including ethanol, cocaine, amphetamine, methamphetamine, and nicotine. We focused mainly on the known genetic and neural mechanisms underlying appetitive reward for sugar and reward for ethanol. We also include genes, molecular pathways, and neural circuits that have been identified using assays that test the palatability of the rewarding

  15. Reward-based spatial learning in unmedicated adults with obsessive-compulsive disorder.

    Science.gov (United States)

    Marsh, Rachel; Tau, Gregory Z; Wang, Zhishun; Huo, Yuankai; Liu, Ge; Hao, Xuejun; Packard, Mark G; Peterson, Bradley S; Simpson, H Blair

    2015-04-01

    The authors assessed the functioning of mesolimbic and striatal areas involved in reward-based spatial learning in unmedicated adults with obsessive-compulsive disorder (OCD). Functional MRI blood-oxygen-level-dependent response was compared in 33 unmedicated adults with OCD and 33 healthy, age-matched comparison subjects during a reward-based learning task that required learning to use extramaze cues to navigate a virtual eight-arm radial maze to find hidden rewards. The groups were compared in their patterns of brain activation associated with reward-based spatial learning versus a control condition in which rewards were unexpected because they were allotted pseudorandomly to experimentally prevent learning. Both groups learned to navigate the maze to find hidden rewards, but group differences in neural activity during navigation and reward processing were detected in mesolimbic and striatal areas. During navigation, the OCD group, unlike the healthy comparison group, exhibited activation in the left posterior hippocampus. Unlike healthy subjects, participants in the OCD group did not show activation in the left ventral putamen and amygdala when anticipating rewards or in the left hippocampus, amygdala, and ventral putamen when receiving unexpected rewards (control condition). Signal in these regions decreased relative to baseline during unexpected reward receipt among those in the OCD group, and the degree of activation was inversely associated with doubt/checking symptoms. Participants in the OCD group displayed abnormal recruitment of mesolimbic and ventral striatal circuitry during reward-based spatial learning. Whereas healthy comparison subjects exhibited activation in this circuitry in response to the violation of reward expectations, unmedicated OCD participants did not and instead over-relied on the posterior hippocampus during learning. Thus, dopaminergic innervation of reward circuitry may be altered, and future study of anterior/posterior hippocampal

  16. Higher resting-state activity in reward-related brain circuits in obese versus normal-weight females independent of food intake

    OpenAIRE

    Hogenkamp, P S; Zhou, W; Dahlberg, L S; Stark, J; Larsen, A L; Olivo, G; Wiemerslage, L; Larsson, E-M; Sundbom, M; Benedict, C; Schi?th, H B

    2016-01-01

    BACKGROUND: In response to food cues, obese vs normal-weight individuals show greater activation in brain regions involved in the regulation of food intake under both fasted and sated conditions. Putative effects of obesity on task-independent low-frequency blood-oxygenation-level-dependent signals-that is, resting-state brain activity-in the context of food intake are, however, less well studied. OBJECTIVE: To compare eyes closed, whole-brain low-frequency BOLD signals between severely obese...

  17. The role of reward and reward uncertainty in episodic memory

    OpenAIRE

    Mason, Alice; Farrell, Simon; Howard-Jones, Paul; Ludwig, Casimir

    2017-01-01

    Declarative memory has been found to be sensitive to reward-related changes in the environment. The reward signal can be broken down into information regarding the expected value of the reward, reward uncertainty and the prediction error. Research has established that high as opposed to low reward values enhance declarative memory. Research in neuroscience suggests that high uncertainty activates the reward system, which could lead to enhanced learning and memory. Here we present the results ...

  18. Hidden neural networks

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose; Riis, Søren Kamaric

    1999-01-01

    A general framework for hybrids of hidden Markov models (HMMs) and neural networks (NNs) called hidden neural networks (HNNs) is described. The article begins by reviewing standard HMMs and estimation by conditional maximum likelihood, which is used by the HNN. In the HNN, the usual HMM probability...... parameters are replaced by the outputs of state-specific neural networks. As opposed to many other hybrids, the HNN is normalized globally and therefore has a valid probabilistic interpretation. All parameters in the HNN are estimated simultaneously according to the discriminative conditional maximum...... likelihood criterion. The HNN can be viewed as an undirected probabilistic independence network (a graphical model), where the neural networks provide a compact representation of the clique functions. An evaluation of the HNN on the task of recognizing broad phoneme classes in the TIMIT database shows clear...

  19. A hidden history

    OpenAIRE

    Peppers, Emily

    2008-01-01

    The Cultural Collections Audit project began at the University of Edinburgh in 2004, searching for hidden treasures in its 'distributed heritage collections' across the university. The objects and collections recorded in the Audit ranged widely from fine art and furniture to historical scientific and teaching equipment and personalia relating to key figures in the university's long tradition of academic excellence. This information was gathered in order to create a central database of informa...

  20. Distinguishing Hidden Markov Chains

    OpenAIRE

    Kiefer, Stefan; Sistla, A. Prasad

    2015-01-01

    Hidden Markov Chains (HMCs) are commonly used mathematical models of probabilistic systems. They are employed in various fields such as speech recognition, signal processing, and biological sequence analysis. We consider the problem of distinguishing two given HMCs based on an observation sequence that one of the HMCs generates. More precisely, given two HMCs and an observation sequence, a distinguishing algorithm is expected to identify the HMC that generates the observation sequence. Two HM...

  1. Coupling of Hidden Sector

    OpenAIRE

    Królikowski, Wojciech

    2016-01-01

    A hypothetic Hidden Sector of the Universe, consisting of sterile fer\\-mions (``sterinos'') and sterile mediating bosons (``sterons'') of mass dimension 1 (not 2!) --- the last described by an antisymmetric tensor field --- requires to exist also a scalar isovector and scalar isoscalar in order to be able to construct electroweak invariant coupling (before spontaneously breaking its symmetry). The introduced scalar isoscalar might be a resonant source for the diphoton excess of 750 GeV, sugge...

  2. Reward Merit with Praise.

    Science.gov (United States)

    Andrews, Hans A.

    1987-01-01

    Describes the efforts of two educational institutions to reward teaching excellence using positive feedback rather than merit pay incentives. An Arizona district, drawing on Herzberg's motivation theories, offers highly individualized rewards ranging from computers to conference money, while an Illinois community college bestows engraved plaques…

  3. Dopamine reward prediction error coding.

    Science.gov (United States)

    Schultz, Wolfram

    2016-03-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.

  4. The endocannabinoid system and nondrug rewarding behaviours.

    Science.gov (United States)

    Fattore, Liana; Melis, Miriam; Fadda, Paola; Pistis, Marco; Fratta, Walter

    2010-07-01

    Rewarding behaviours such as sexual activity, eating, nursing, parenting, social interactions, and play activity are conserved strongly in evolution, and they are essential for development and survival. All of these behaviours are enjoyable and represent pleasant experiences with a high reward value. Remarkably, rewarding behaviours activate the same brain circuits that mediate the positive reinforcing effects of drugs of abuse and of other forms of addiction, such as gambling and food addiction. Given the involvement of the endocannabinoid system in a variety of physiological functions of the nervous system, it is not surprising that it takes part in the complex machinery that regulates gratification and perception of pleasure. In this review, we focus first on the role of the endocannabinoid system in the modulation of neural activity and synaptic functions in brain regions that are involved in natural and nonnatural rewards (namely, the ventral tegmental area, striatum, amygdala, and prefrontal cortex). Then, we examine the role of the endocannabinoid system in modulating behaviours that directly or indirectly activate these brain reward pathways. More specifically, current knowledge of the effects of the pharmacological manipulation of the endocannabinoid system on natural (eating, sexual behaviour, parenting, and social play) and pathological (gambling) rewarding behaviours is summarised and discussed. Copyright 2010 Elsevier Inc. All rights reserved.

  5. Hidden Markov Model for Stock Selection

    Directory of Open Access Journals (Sweden)

    Nguyet Nguyen

    2015-10-01

    Full Text Available The hidden Markov model (HMM is typically used to predict the hidden regimes of observation data. Therefore, this model finds applications in many different areas, such as speech recognition systems, computational molecular biology and financial market predictions. In this paper, we use HMM for stock selection. We first use HMM to make monthly regime predictions for the four macroeconomic variables: inflation (consumer price index (CPI, industrial production index (INDPRO, stock market index (S&P 500 and market volatility (VIX. At the end of each month, we calibrate HMM’s parameters for each of these economic variables and predict its regimes for the next month. We then look back into historical data to find the time periods for which the four variables had similar regimes with the forecasted regimes. Within those similar periods, we analyze all of the S&P 500 stocks to identify which stock characteristics have been well rewarded during the time periods and assign scores and corresponding weights for each of the stock characteristics. A composite score of each stock is calculated based on the scores and weights of its features. Based on this algorithm, we choose the 50 top ranking stocks to buy. We compare the performances of the portfolio with the benchmark index, S&P 500. With an initial investment of $100 in December 1999, over 15 years, in December 2014, our portfolio had an average gain per annum of 14.9% versus 2.3% for the S&P 500.

  6. Finger Millet: A "Certain" Crop for an "Uncertain" Future and a Solution to Food Insecurity and Hidden Hunger under Stressful Environments.

    Science.gov (United States)

    Gupta, Sanjay Mohan; Arora, Sandeep; Mirza, Neelofar; Pande, Anjali; Lata, Charu; Puranik, Swati; Kumar, J; Kumar, Anil

    2017-01-01

    Crop growth and productivity has largely been vulnerable to various abiotic and biotic stresses that are only set to be compounded due to global climate change. Therefore developing improved varieties and designing newer approaches for crop improvement against stress tolerance have become a priority now-a-days. However, most of the crop improvement strategies are directed toward staple cereals such as rice, wheat, maize etc., whereas attention on minor cereals such as finger millet [ Eleusine coracana (L.) Gaertn.] lags far behind. It is an important staple in several semi-arid and tropical regions of the world with excellent nutraceutical properties as well as ensuring food security in these areas even during harsh environment. This review highlights the importance of finger millet as a model nutraceutical crop. Progress and prospects in genetic manipulation for the development of abiotic and biotic stress tolerant varieties is also discussed. Although limited studies have been conducted for genetic improvement of finger millets, its nutritional significance in providing minerals, calories and protein makes it an ideal model for nutrition-agriculture research. Therefore, improved genetic manipulation of finger millets for resistance to both abiotic and biotic stresses, as well as for enhancing nutrient content will be very effective in millet improvement. Key message: Apart from the excellent nutraceutical value of finger millet, its ability to tolerate various abiotic stresses and resist pathogens make it an excellent model for exploring vast genetic and genomic potential of this crop, which provide us a wide choice for developing strategies for making climate resilient staple crops.

  7. Finger Millet: A “Certain” Crop for an “Uncertain” Future and a Solution to Food Insecurity and Hidden Hunger under Stressful Environments

    Science.gov (United States)

    Gupta, Sanjay Mohan; Arora, Sandeep; Mirza, Neelofar; Pande, Anjali; Lata, Charu; Puranik, Swati; Kumar, J.; Kumar, Anil

    2017-01-01

    Crop growth and productivity has largely been vulnerable to various abiotic and biotic stresses that are only set to be compounded due to global climate change. Therefore developing improved varieties and designing newer approaches for crop improvement against stress tolerance have become a priority now-a-days. However, most of the crop improvement strategies are directed toward staple cereals such as rice, wheat, maize etc., whereas attention on minor cereals such as finger millet [Eleusine coracana (L.) Gaertn.] lags far behind. It is an important staple in several semi-arid and tropical regions of the world with excellent nutraceutical properties as well as ensuring food security in these areas even during harsh environment. This review highlights the importance of finger millet as a model nutraceutical crop. Progress and prospects in genetic manipulation for the development of abiotic and biotic stress tolerant varieties is also discussed. Although limited studies have been conducted for genetic improvement of finger millets, its nutritional significance in providing minerals, calories and protein makes it an ideal model for nutrition-agriculture research. Therefore, improved genetic manipulation of finger millets for resistance to both abiotic and biotic stresses, as well as for enhancing nutrient content will be very effective in millet improvement. Key message: Apart from the excellent nutraceutical value of finger millet, its ability to tolerate various abiotic stresses and resist pathogens make it an excellent model for exploring vast genetic and genomic potential of this crop, which provide us a wide choice for developing strategies for making climate resilient staple crops. PMID:28487720

  8. Finger Millet: A “Certain” Crop for an “Uncertain” Future and a Solution to Food Insecurity and Hidden Hunger under Stressful Environments

    Directory of Open Access Journals (Sweden)

    Anil Kumar

    2017-04-01

    Full Text Available Crop growth and productivity has largely been vulnerable to various abiotic and biotic stresses that are only set to be compounded due to global climate change. Therefore developing improved varieties and designing newer approaches for crop improvement against stress tolerance have become a priority now-a-days. However, most of the crop improvement strategies are directed toward staple cereals such as rice, wheat, maize etc., whereas attention on minor cereals such as finger millet [Eleusine coracana (L. Gaertn.] lags far behind. It is an important staple in several semi-arid and tropical regions of the world with excellent nutraceutical properties as well as ensuring food security in these areas even during harsh environment. This review highlights the importance of finger millet as a model nutraceutical crop. Progress and prospects in genetic manipulation for the development of abiotic and biotic stress tolerant varieties is also discussed. Although limited studies have been conducted for genetic improvement of finger millets, its nutritional significance in providing minerals, calories and protein makes it an ideal model for nutrition-agriculture research. Therefore, improved genetic manipulation of finger millets for resistance to both abiotic and biotic stresses, as well as for enhancing nutrient content will be very effective in millet improvement.Key message: Apart from the excellent nutraceutical value of finger millet, its ability to tolerate various abiotic stresses and resist pathogens make it an excellent model for exploring vast genetic and genomic potential of this crop, which provide us a wide choice for developing strategies for making climate resilient staple crops.

  9. Altered social reward and attention in anorexia nervosa

    Directory of Open Access Journals (Sweden)

    Karli K Watson

    2010-09-01

    Full Text Available Dysfunctional social reward and social orienting attend a variety of neuropsychiatric disorders including autism, schizophrenia, social anxiety, and psychopathy. Here we show that similar social reward and attention dysfunction attend anorexia nervosa, a disorder defined by avoidance of food and extreme weight loss. We measured the implicit reward value of social stimuli for female participants with (n=11 and without (n=11 anorexia nervosa using an econometric choice task and also tracked gaze patterns during free viewing of images of female faces and bodies. As predicted, the reward value of viewing bodies varied inversely with observed body weight for women with anorexia but not neurotypical women, in contrast with their explicit ratings of attractiveness. Surprisingly, women with anorexia nervosa, unlike neurotypical women, did not find female faces rewarding and avoided looking at both the face and eyes—independent of observed body weight. These findings demonstrate comorbid dysfunction in the neural circuits mediating gustatory and social reward in anorexia nervosa.

  10. Stress, eating and the reward system.

    Science.gov (United States)

    Adam, Tanja C; Epel, Elissa S

    2007-07-24

    An increasing number of people report concerns about the amount of stress in their life. At the same time obesity is an escalating health problem worldwide. Evidence is accumulating rapidly that stress related chronic stimulation of the hypothalamic-pituitary-adrenal (HPA) axis and resulting excess glucocorticoid exposure may play a potential role in the development of visceral obesity. Since adequate regulation of energy and food intake under stress is important for survival, it is not surprising that the HPA axis is not only the 'conductor' of an appropriate stress response, but is also tightly intertwined with the endocrine regulation of appetite. Here we attempt to link animal and human literatures to tease apart how different types of psychological stress affect eating. We propose a theoretical model of Reward Based Stress Eating. This model emphasizes the role of cortisol and reward circuitry on motivating calorically dense food intake, and elucidating potential neuroendocrine mediators in the relationship between stress and eating. The addiction literature suggests that the brain reward circuitry may be a key player in stress-induced food intake. Stress as well as palatable food can stimulate endogenous opioid release. In turn, opioid release appears to be part of an organisms' powerful defense mechanism protecting from the detrimental effects of stress by decreasing activity of the HPA axis and thus attenuating the stress response. Repeated stimulation of the reward pathways through either stress induced HPA stimulation, intake of highly palatable food or both, may lead to neurobiological adaptations that promote the compulsive nature of overeating. Cortisol may influence the reward value of food via neuroendocrine/peptide mediators such as leptin, insulin and neuropeptide Y (NPY). Whereas glucocorticoids are antagonized by insulin and leptin acutely, under chronic stress, that finely balanced system is dysregulated, possibly contributing to increased food

  11. Facilitation of voluntary goal-directed action by reward cues.

    Science.gov (United States)

    Lovibond, Peter F; Colagiuri, Ben

    2013-10-01

    Reward-associated cues are known to influence motivation to approach both natural and man-made rewards, such as food and drugs. However, the mechanisms underlying these effects are not well understood. To model these processes in the laboratory with humans, we developed an appetitive Pavlovian-instrumental transfer procedure with a chocolate reward. We used a single unconstrained response that led to an actual rather than symbolic reward to assess the strength of reward motivation. Presentation of a chocolate-paired cue, but not an unpaired cue, markedly enhanced instrumental responding over a 30-s period. The same pattern was observed with 10-s and 30-s cues, showing that close cue-reward contiguity is not necessary for facilitation of reward-directed action. The results confirm that reward-related cues can instigate voluntary action to obtain that reward. The effectiveness of long-duration cues suggests that in clinical settings, attention should be directed to both proximal and distal cues for reward.

  12. Localization of hidden Chua's attractors

    International Nuclear Information System (INIS)

    Leonov, G.A.; Kuznetsov, N.V.; Vagaitsev, V.I.

    2011-01-01

    The classical attractors of Lorenz, Rossler, Chua, Chen, and other widely-known attractors are those excited from unstable equilibria. From computational point of view this allows one to use numerical method, in which after transient process a trajectory, started from a point of unstable manifold in the neighborhood of equilibrium, reaches an attractor and identifies it. However there are attractors of another type: hidden attractors, a basin of attraction of which does not contain neighborhoods of equilibria. In the present Letter for localization of hidden attractors of Chua's circuit it is suggested to use a special analytical-numerical algorithm. -- Highlights: → There are hidden attractors: basin doesn't contain neighborhoods of equilibria. → Hidden attractors cannot be reached by trajectory from neighborhoods of equilibria. → We suggested special procedure for localization of hidden attractors. → We discovered hidden attractor in Chua's system, L. Chua in his work didn't expect this.

  13. Hidden Liquidity: Determinants and Impact

    OpenAIRE

    Gökhan Cebiroglu; Ulrich Horst

    2012-01-01

    We cross-sectionally analyze the presence of aggregated hidden depth and trade volume in the S&P 500 and identify its key determinants. We find that the spread is the main predictor for a stock’s hidden dimension, both in terms of traded and posted liquidity. Our findings moreover suggest that large hidden orders are associated with larger transaction costs, higher price impact and increased volatility. In particular, as large hidden orders fail to attract (latent) liquidity to the market, ...

  14. Model Checking Markov Reward Models with Impulse Rewards

    NARCIS (Netherlands)

    Cloth, Lucia; Katoen, Joost-Pieter; Khattri, Maneesh; Pulungan, Reza; Bondavalli, Andrea; Haverkort, Boudewijn; Tang, Dong

    This paper considers model checking of Markov reward models (MRMs), continuous-time Markov chains with state rewards as well as impulse rewards. The reward extension of the logic CSL (Continuous Stochastic Logic) is interpreted over such MRMs, and two numerical algorithms are provided to check the

  15. Association of the FTO fat mass and obesity-associated gene rs9939609 polymorphism with rewarding value of food and eating behavior in Chilean children.

    Science.gov (United States)

    Obregón Rivas, Ana Maria; Santos, Jose L; Valladares, Macarena A; Cameron, Jameson; Goldfield, Gary

    2018-03-27

    The aim of this study was to assess the association between the single-nucleotide polymorphism rs9939609 in the FTO gene and homeostatic/non-homeostatic eating behavior patterns in Chilean children. A cross-sectional study was conducted in 258 children (44% female; 8-14 y of age). Anthropometric measurements (weight, height, Z-score of height, body mass index, and waist circumference) were performed. Eating behavior was assessed using the Eating in Absence of Hunger Questionnaire; the Child Eating Behavior Questionnaire; the Three Factor Eating Questionnaire, and the Food Reinforcement Value Questionnaire. Genotype of rs9939609 was determined by a Taqman assay. Association of rs9939609 with eating behavior was assessed using non-parametric tests. Allelic frequencies of rs9939609 were estimated as 77% for the A allele and 23% for the T allele. We found that normal-weight girl A carriers had higher scores of Satiety Responsiveness and Slowness on the Eating subscale. Normal-weight boy A carriers showed significantly higher scores on the Negative Affect and lower scores of the Desire to Drink subscale. In overweight children, A carriers showed higher scores on the Food Responsiveness, Emotional Overeating, Enjoyment of Food, and Food Choice subscales and lower scores on the Satiety- Responsiveness and Slowness in Eating subscales. In obese children, we found higher scores on the Cognitive Restrained subscale and lower Food Choice. The rs9939609 A allele of the FTO gene is associated with eating behavior traits and may predispose to obesity. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Higher resting-state activity in reward-related brain circuits in obese versus normal-weight females independent of food intake.

    Science.gov (United States)

    Hogenkamp, P S; Zhou, W; Dahlberg, L S; Stark, J; Larsen, A L; Olivo, G; Wiemerslage, L; Larsson, E-M; Sundbom, M; Benedict, C; Schiöth, H B

    2016-11-01

    In response to food cues, obese vs normal-weight individuals show greater activation in brain regions involved in the regulation of food intake under both fasted and sated conditions. Putative effects of obesity on task-independent low-frequency blood-oxygenation-level-dependent signals-that is, resting-state brain activity-in the context of food intake are, however, less well studied. To compare eyes closed, whole-brain low-frequency BOLD signals between severely obese and normal-weight females, as assessed by functional magnetic resonance imaging (fMRI). Fractional amplitude of low-frequency fluctuations were measured in the morning following an overnight fast in 17 obese (age: 39±11 years, body mass index (BMI): 42.3±4.8 kg m - 2 ) and 12 normal-weight females (age: 36±12 years, BMI: 22.7±1.8 kg m - 2 ), both before and 30 min after consumption of a standardized meal (~260 kcal). Compared with normal-weight controls, obese females had increased low-frequency activity in clusters located in the putamen, claustrum and insula (Pfood intake. Self-reported hunger dropped and plasma glucose concentrations increased after food intake (Pfood intake under the experimental settings applied in the current study. Future studies involving males and females, as well as utilizing repeated post-prandial resting-state fMRI scans and various types of meals are needed to further investigate how food intake alters resting-state brain activity in obese humans.

  17. Neural coding of basic reward terms of animal learning theory, game theory, microeconomics and behavioural ecology.

    Science.gov (United States)

    Schultz, Wolfram

    2004-04-01

    Neurons in a small number of brain structures detect rewards and reward-predicting stimuli and are active during the expectation of predictable food and liquid rewards. These neurons code the reward information according to basic terms of various behavioural theories that seek to explain reward-directed learning, approach behaviour and decision-making. The involved brain structures include groups of dopamine neurons, the striatum including the nucleus accumbens, the orbitofrontal cortex and the amygdala. The reward information is fed to brain structures involved in decision-making and organisation of behaviour, such as the dorsolateral prefrontal cortex and possibly the parietal cortex. The neural coding of basic reward terms derived from formal theories puts the neurophysiological investigation of reward mechanisms on firm conceptual grounds and provides neural correlates for the function of rewards in learning, approach behaviour and decision-making.

  18. ESO's Hidden Treasures Brought to Light

    Science.gov (United States)

    2011-01-01

    ESO's Hidden Treasures 2010 astrophotography competition attracted nearly 100 entries, and ESO is delighted to announce the winners. Hidden Treasures gave amateur astronomers the opportunity to search ESO's vast archives of astronomical data for a well-hidden cosmic gem. Astronomy enthusiast Igor Chekalin from Russia won the first prize in this difficult but rewarding challenge - the trip of a lifetime to ESO's Very Large Telescope at Paranal, Chile. The pictures of the Universe that can be seen in ESO's releases are impressive. However, many hours of skilful work are required to assemble the raw greyscale data captured by the telescopes into these colourful images, correcting them for distortions and unwanted signatures of the instrument, and enhancing them so as to bring out the details contained in the astronomical data. ESO has a team of professional image processors, but for the ESO's Hidden Treasures 2010 competition, the experts decided to give astronomy and photography enthusiasts the opportunity to show the world what they could do with the mammoth amount of data contained in ESO's archives. The enthusiasts who responded to the call submitted nearly 100 entries in total - far exceeding initial expectations, given the difficult nature of the challenge. "We were completely taken aback both by the quantity and the quality of the images that were submitted. This was not a challenge for the faint-hearted, requiring both an advanced knowledge of data processing and an artistic eye. We are thrilled to have discovered so many talented people," said Lars Lindberg Christensen, Head of ESO's education and Public Outreach Department. Digging through many terabytes of professional astronomical data, the entrants had to identify a series of greyscale images of a celestial object that would reveal the hidden beauty of our Universe. The chance of a great reward for the lucky winner was enough to spur on the competitors; the first prize being a trip to ESO's Very Large

  19. Reward and punishment.

    Science.gov (United States)

    Sigmund, K; Hauert, C; Nowak, M A

    2001-09-11

    Minigames capturing the essence of Public Goods experiments show that even in the absence of rationality assumptions, both punishment and reward will fail to bring about prosocial behavior. This result holds in particular for the well-known Ultimatum Game, which emerges as a special case. But reputation can induce fairness and cooperation in populations adapting through learning or imitation. Indeed, the inclusion of reputation effects in the corresponding dynamical models leads to the evolution of economically productive behavior, with agents contributing to the public good and either punishing those who do not or rewarding those who do. Reward and punishment correspond to two types of bifurcation with intriguing complementarity. The analysis suggests that reputation is essential for fostering social behavior among selfish agents, and that it is considerably more effective with punishment than with reward.

  20. A Markov reward model checker

    NARCIS (Netherlands)

    Katoen, Joost P.; Maneesh Khattri, M.; Zapreev, I.S.; Zapreev, I.S.

    2005-01-01

    This short tool paper introduces MRMC, a model checker for discrete-time and continuous-time Markov reward models. It supports reward extensions of PCTL and CSL, and allows for the automated verification of properties concerning long-run and instantaneous rewards as well as cumulative rewards. In

  1. Reward, Context, and Human Behaviour

    Directory of Open Access Journals (Sweden)

    Clare L. Blaukopf

    2007-01-01

    Full Text Available Animal models of reward processing have revealed an extensive network of brain areas that process different aspects of reward, from expectation and prediction to calculation of relative value. These results have been confirmed and extended in human neuroimaging to encompass secondary rewards more unique to humans, such as money. The majority of the extant literature covers the brain areas associated with rewards whilst neglecting analysis of the actual behaviours that these rewards generate. This review strives to redress this imbalance by illustrating the importance of looking at the behavioural outcome of rewards and the context in which they are produced. Following a brief review of the literature of reward-related activity in the brain, we examine the effect of reward context on actions. These studies reveal how the presence of reward vs. reward and punishment, or being conscious vs. unconscious of reward-related actions, differentially influence behaviour. The latter finding is of particular importance given the extent to which animal models are used in understanding the reward systems of the human mind. It is clear that further studies are needed to learn about the human reaction to reward in its entirety, including any distinctions between conscious and unconscious behaviours. We propose that studies of reward entail a measure of the animal's (human or nonhuman knowledge of the reward and knowledge of its own behavioural outcome to achieve that reward.

  2. Hidden Risk Factors for Women

    Science.gov (United States)

    ... A.S.T. Quiz Hidden Stroke Risk Factors for Women Updated:Nov 22,2016 Excerpted from "What Women Need To Know About The Hidden Risk Factors ... 2012) This year, more than 100,000 U.S. women under 65 will have a stroke. Stroke is ...

  3. Higgs Portal into Hidden Sectors

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    Several attractive theoretical ideas suggest the existence of one or more 'hidden sectors' consisting of standard model singlet fields, some of which may not be too heavy. There is a profound reason to think that the Higgs sector might provide the first access to these hidden sectors. This scenario could affect Higgs phenomenology in drastic ways.

  4. Reward Circuitry in Addiction.

    Science.gov (United States)

    Cooper, Sarah; Robison, A J; Mazei-Robison, Michelle S

    2017-07-01

    Understanding the brain circuitry that underlies reward is critical to improve treatment for many common health issues, including obesity, depression, and addiction. Here we focus on insights into the organization and function of reward circuitry and its synaptic and structural adaptations in response to cocaine exposure. While the importance of certain circuits, such as the mesocorticolimbic dopamine pathway, are well established in drug reward, recent studies using genetics-based tools have revealed functional changes throughout the reward circuitry that contribute to different facets of addiction, such as relapse and craving. The ability to observe and manipulate neuronal activity within specific cell types and circuits has led to new insight into not only the basic connections between brain regions, but also the molecular changes within these specific microcircuits, such as neurotrophic factor and GTPase signaling or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor function, that underlie synaptic and structural plasticity evoked by drugs of abuse. Excitingly, these insights from preclinical rodent work are now being translated into the clinic, where transcranial magnetic simulation and deep brain stimulation therapies are being piloted in human cocaine dependence. Thus, this review seeks to summarize current understanding of the major brain regions implicated in drug-related behaviors and the molecular mechanisms that contribute to altered connectivity between these regions, with the postulation that increased knowledge of the plasticity within the drug reward circuit will lead to new and improved treatments for addiction.

  5. Hidden attractors in dynamical systems

    Science.gov (United States)

    Dudkowski, Dawid; Jafari, Sajad; Kapitaniak, Tomasz; Kuznetsov, Nikolay V.; Leonov, Gennady A.; Prasad, Awadhesh

    2016-06-01

    Complex dynamical systems, ranging from the climate, ecosystems to financial markets and engineering applications typically have many coexisting attractors. This property of the system is called multistability. The final state, i.e., the attractor on which the multistable system evolves strongly depends on the initial conditions. Additionally, such systems are very sensitive towards noise and system parameters so a sudden shift to a contrasting regime may occur. To understand the dynamics of these systems one has to identify all possible attractors and their basins of attraction. Recently, it has been shown that multistability is connected with the occurrence of unpredictable attractors which have been called hidden attractors. The basins of attraction of the hidden attractors do not touch unstable fixed points (if exists) and are located far away from such points. Numerical localization of the hidden attractors is not straightforward since there are no transient processes leading to them from the neighborhoods of unstable fixed points and one has to use the special analytical-numerical procedures. From the viewpoint of applications, the identification of hidden attractors is the major issue. The knowledge about the emergence and properties of hidden attractors can increase the likelihood that the system will remain on the most desirable attractor and reduce the risk of the sudden jump to undesired behavior. We review the most representative examples of hidden attractors, discuss their theoretical properties and experimental observations. We also describe numerical methods which allow identification of the hidden attractors.

  6. Neurocircuitry of drug reward

    Science.gov (United States)

    Ikemoto, Satoshi; Bonci, Antonello

    2013-01-01

    In recent years, neuroscientists have produced profound conceptual and mechanistic advances on the neurocircuitry of reward and substance use disorders. Here, we will provide a brief review of intracranial drug self-administration and optogenetic self-stimulation studies that identified brain regions and neurotransmitter systems involved in drug- and reward-related behaviors. Also discussed is a theoretical framework that helps to understand the functional properties of the circuitry involved in these behaviors. The circuitry appears to be homeostatically regulated and mediate anticipatory processes that regulate behavioral interaction with the environment in response to salient stimuli. That is, abused drugs or, at least, some may act on basic motivation and mood processes, regulating behavior-environment interaction. Optogenetics and related technologies have begun to uncover detailed circuit mechanisms linking key brain regions in which abused drugs act for rewarding effects. PMID:23664810

  7. Neural Processing of Calories in Brain Reward Areas Can be Modulated by Reward Sensitivity.

    Science.gov (United States)

    van Rijn, Inge; Griffioen-Roose, Sanne; de Graaf, Cees; Smeets, Paul A M

    2015-01-01

    A food's reward value is dependent on its caloric content. Furthermore, a food's acute reward value also depends on hunger state. The drive to obtain rewards (reward sensitivity), however, differs between individuals. Here, we assessed the association between brain responses to calories in the mouth and trait reward sensitivity in different hunger states. Firstly, we assessed this in data from a functional neuroimaging study (van Rijn et al., 2015), in which participants (n = 30) tasted simple solutions of a non-caloric sweetener with or without a non-sweet carbohydrate (maltodextrin) during hunger and satiety. Secondly, we expanded these analyses to regular drinks by assessing the same relationship in data from a study in which soft drinks sweetened with either sucrose or a non-caloric sweetener were administered during hunger (n = 18) (Griffioen-Roose et al., 2013). First, taste activation by the non-caloric solution/soft drink was subtracted from that by the caloric solution/soft drink to eliminate sweetness effects and retain activation induced by calories. Subsequently, this difference in taste activation was correlated with reward sensitivity as measured with the BAS drive subscale of the Behavioral Activation System (BAS) questionnaire. When participants were hungry and tasted calories from the simple solution, brain activation in the right ventral striatum (caudate), right amygdala and anterior cingulate cortex (bilaterally) correlated negatively with BAS drive scores. In contrast, when participants were satiated, taste responses correlated positively with BAS drive scores in the left caudate. These results were not replicated for soft drinks. Thus, neural responses to oral calories from maltodextrin were modulated by reward sensitivity in reward-related brain areas. This was not the case for sucrose. This may be due to the direct detection of maltodextrin, but not sucrose in the oral cavity. Also, in a familiar beverage, detection of calories per se may be

  8. Reward deficiency and anti-reward in pain chronification

    OpenAIRE

    Borsook, D.; Linnman, C.; Faria, Vanda; Strassman, A. M.; Becerra, L.; Elman, I.

    2016-01-01

    Converging lines of evidence suggest that the pathophysiology of pain is mediated to a substantial degree via allostatic neuroadaptations in reward- and stress-related brain circuits. Thus, reward deficiency (RD) represents a within-system neuroadaptation to pain-induced protracted activation of the reward circuits that leads to depletion-like hypodopaminergia, clinically manifested anhedonia, and diminished motivation for natural reinforcers. Anti-reward (AR) conversely pertains to a between...

  9. Variational Infinite Hidden Conditional Random Fields

    NARCIS (Netherlands)

    Bousmalis, Konstantinos; Zafeiriou, Stefanos; Morency, Louis-Philippe; Pantic, Maja; Ghahramani, Zoubin

    2015-01-01

    Hidden conditional random fields (HCRFs) are discriminative latent variable models which have been shown to successfully learn the hidden structure of a given classification problem. An Infinite hidden conditional random field is a hidden conditional random field with a countably infinite number of

  10. Managing Hidden Costs of Offshoring

    DEFF Research Database (Denmark)

    Larsen, Marcus M.; Pedersen, Torben

    2014-01-01

    This chapter investigates the concept of the ‘hidden costs’ of offshoring, i.e. unexpected offshoring costs exceeding the initially expected costs. Due to the highly undefined nature of these costs, we position our analysis towards the strategic responses of firms’ realisation of hidden costs....... In this regard, we argue that a major response to the hidden costs of offshoring is the identification and utilisation of strategic mechanisms in the organisational design to eventually achieving system integration in a globally dispersed and disaggregated organisation. This is heavily moderated by a learning......-by-doing process, where hidden costs motivate firms and their employees to search for new and better knowledge on how to successfully manage the organisation. We illustrate this thesis based on the case of the LEGO Group....

  11. The Hidden Costs of Offshoring

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Manning, Stephan; Pedersen, Torben

    2011-01-01

    of offshoring. Specifically, we propose that hidden costs can be explained by the combination of increasing structural, operational and social complexity of offshoring activities. In addition, we suggest that firm orientation towards organizational design as part of an offshoring strategy and offshoring......This study seeks to explain hidden costs of offshoring, i.e. unexpected costs resulting from the relocation of business tasks and activities outside the home country. We develop a model that highlights the role of complexity, design orientation and experience in explaining hidden costs...... experience moderate the relationship between complexity and hidden costs negatively i.e. reduces the cost generating impact of complexity. We develop three hypotheses and test them on comprehensive data from the Offshoring Research Network (ORN). In general, we find support for our hypotheses. A key result...

  12. Child Abuse: The Hidden Bruises

    Science.gov (United States)

    ... for Families - Vietnamese Spanish Facts for Families Guide Child Abuse - The Hidden Bruises No. 5; Updated November 2014 The statistics on physical child abuse are alarming. It is estimated hundreds of thousands ...

  13. Working memory and reward association learning impairments in obesity.

    Science.gov (United States)

    Coppin, Géraldine; Nolan-Poupart, Sarah; Jones-Gotman, Marilyn; Small, Dana M

    2014-12-01

    Obesity has been associated with impaired executive functions including working memory. Less explored is the influence of obesity on learning and memory. In the current study we assessed stimulus reward association learning, explicit learning and memory and working memory in healthy weight, overweight and obese individuals. Explicit learning and memory did not differ as a function of group. In contrast, working memory was significantly and similarly impaired in both overweight and obese individuals compared to the healthy weight group. In the first reward association learning task the obese, but not healthy weight or overweight participants consistently formed paradoxical preferences for a pattern associated with a negative outcome (fewer food rewards). To determine if the deficit was specific to food reward a second experiment was conducted using money. Consistent with Experiment 1, obese individuals selected the pattern associated with a negative outcome (fewer monetary rewards) more frequently than healthy weight individuals and thus failed to develop a significant preference for the most rewarded patterns as was observed in the healthy weight group. Finally, on a probabilistic learning task, obese compared to healthy weight individuals showed deficits in negative, but not positive outcome learning. Taken together, our results demonstrate deficits in working memory and stimulus reward learning in obesity and suggest that obese individuals are impaired in learning to avoid negative outcomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Hidden Statistics of Schroedinger Equation

    Science.gov (United States)

    Zak, Michail

    2011-01-01

    Work was carried out in determination of the mathematical origin of randomness in quantum mechanics and creating a hidden statistics of Schr dinger equation; i.e., to expose the transitional stochastic process as a "bridge" to the quantum world. The governing equations of hidden statistics would preserve such properties of quantum physics as superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods.

  15. Hidden Curriculum: An Analytical Definition

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Andarvazh

    2018-03-01

    Full Text Available Background: The concept of hidden curriculum was first used by Philip Jackson in 1968, and Hafferty brought this concept to the medical education. Many of the subjects that medical students learn are attributed to this curriculum. So far several definitions have been presented for the hidden curriculum, which on the one hand made this concept richer, and on the other hand, led to confusion and ambiguity.This paper tries to provide a clear and comprehensive definition of it.Methods: In this study, concept analysis of McKenna method was used. Using keywords and searching in the databases, 561 English and 26 Persian references related to the concept was found, then by limitingthe research scope, 125 abstracts and by finding more relevant references, 55 articles were fully studied.Results: After analyzing the definitions by McKenna method, the hidden curriculum is defined as follows: The hidden curriculum is a hidden, powerful, intrinsic in organizational structure and culture and sometimes contradictory message, conveyed implicitly and tacitly in the learning environment by structural and human factors and its contents includes cultural habits and customs, norms, values, belief systems, attitudes, skills, desires and behavioral and social expectations can have a positive or negative effect, unplanned, neither planners nor teachers, nor learners are aware of it. The ultimate consequence of the hidden curriculum includes reproducing the existing class structure, socialization, and familiarizing learners for transmission and joining the professional world.Conclusion: Based on the concept analysis, we arrived at an analytical definition of the hidden curriculum that could be useful for further studies in this area.Keywords: CONCEPT ANALYSIS, HIDDEN CURRICULUM, MCKENNA’S METHOD

  16. Bribes or Rewards.

    Science.gov (United States)

    Megyeri, Kathy A.

    Small tangible rewards for student progress, such as candy bars, pens, or ribbons, add potency to the verbal and written praise offered by the teacher, thus increasing student motivation. Giving students small prizes enhances the cooperative atmosphere of learning, especially for those who do not normally do well. Research indicates that low…

  17. Mexico City normal weight children exposed to high concentrations of ambient PM2.5 show high blood leptin and endothelin-1, vitamin D deficiency, and food reward hormone dysregulation versus low pollution controls. Relevance for obesity and Alzheimer disease.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Franco-Lira, Maricela; D'Angiulli, Amedeo; Rodríguez-Díaz, Joel; Blaurock-Busch, Eleonore; Busch, Yvette; Chao, Chih-kai; Thompson, Charles; Mukherjee, Partha S; Torres-Jardón, Ricardo; Perry, George

    2015-07-01

    Millions of Mexico, US and across the world children are overweight and obese. Exposure to fossil-fuel combustion sources increases the risk for obesity and diabetes, while long-term exposure to fine particulate matter (PM2.5) and ozone (O3) above US EPA standards is associated with increased risk of Alzheimer's disease (AD). Mexico City Metropolitan Area children are chronically exposed to PM2.5 and O3 concentrations above the standards and exhibit systemic, brain and intrathecal inflammation, cognitive deficits, and Alzheimer disease neuropathology. We investigated adipokines, food reward hormones, endothelial dysfunction, vitamin D and apolipoprotein E (APOE) relationships in 80 healthy, normal weight 11.1±3.2 year olds matched by age, gender, BMI and SES, low (n: 26) versus high (n:54) PM2.5 exposures. Mexico City children had higher leptin and endothelin-1 (pMexico City APOE 4 versus 3 children had higher glucose (p=0.009). Serum 25-hydroxyvitamin DMexico City children. Leptin is strongly positively associated to PM 2.5 cumulative exposures. Residing in a high PM2.5 and O3 environment is associated with 12h fasting hyperleptinemia, altered appetite-regulating peptides, vitamin D deficiency, and increases in ET-1 in clinically healthy children. These changes could signal the future trajectory of urban children towards the development of insulin resistance, obesity, type II diabetes, premature cardiovascular disease, addiction-like behavior, cognitive impairment and Alzheimer's disease. Increased efforts should be made to decrease pediatric PM2.5 exposures, to deliver health interventions prior to the development of obesity and to identify and mitigate environmental factors influencing obesity and Alzheimer disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Sensitivity to reward: implications for overeating and overweight.

    Science.gov (United States)

    Davis, Caroline; Strachan, Shaelyn; Berkson, Marni

    2004-04-01

    Sensitivity to reward (STR)-a personality trait firmly rooted in the neurobiology of the mesolimbic dopamine system-has been strongly implicated in the risk for addiction. This construct describes the ability to derive pleasure or reward from natural reinforcers like food, and from pharmacologic rewards like addictive drugs. Recently experts in the field of addiction research have acknowledged that psychomotor stimulant drugs are no longer at the heart of all addictions, and that brain circuits can also be deranged with natural rewards like food. The present study tested a model in which STR was expected to relate positively to overeating, which in turn would be associated with higher body weight in woman aged 25-45 years. As predicted, STR was correlated positively with measures of emotional overeating. Also, overweight woman were significantly more sensitive to reward than those of normal weight. Interestingly, however, the obese woman (Body Mass Index>30) were more anhedonic than the overweight woman (Body Mass Index>25reward circuits. Results also indicate that STR may serve as a risk factor for overeating and overweight, especially in cultures such as ours where palatable, calorically-dense food is plentiful.

  19. Reward positivity: Reward prediction error or salience prediction error?

    Science.gov (United States)

    Heydari, Sepideh; Holroyd, Clay B

    2016-08-01

    The reward positivity is a component of the human ERP elicited by feedback stimuli in trial-and-error learning and guessing tasks. A prominent theory holds that the reward positivity reflects a reward prediction error signal that is sensitive to outcome valence, being larger for unexpected positive events relative to unexpected negative events (Holroyd & Coles, 2002). Although the theory has found substantial empirical support, most of these studies have utilized either monetary or performance feedback to test the hypothesis. However, in apparent contradiction to the theory, a recent study found that unexpected physical punishments also elicit the reward positivity (Talmi, Atkinson, & El-Deredy, 2013). The authors of this report argued that the reward positivity reflects a salience prediction error rather than a reward prediction error. To investigate this finding further, in the present study participants navigated a virtual T maze and received feedback on each trial under two conditions. In a reward condition, the feedback indicated that they would either receive a monetary reward or not and in a punishment condition the feedback indicated that they would receive a small shock or not. We found that the feedback stimuli elicited a typical reward positivity in the reward condition and an apparently delayed reward positivity in the punishment condition. Importantly, this signal was more positive to the stimuli that predicted the omission of a possible punishment relative to stimuli that predicted a forthcoming punishment, which is inconsistent with the salience hypothesis. © 2016 Society for Psychophysiological Research.

  20. Dietary phytate, zinc and hidden zinc deficiency.

    Science.gov (United States)

    Sandstead, Harold H; Freeland-Graves, Jeanne H

    2014-10-01

    Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

  1. Hidden ion population: Revisited

    International Nuclear Information System (INIS)

    Olsen, R.C.; Chappell, C.R.; Gallagher, D.L.; Green, J.L.; Gurnett, D.A.

    1985-01-01

    Satellite potentials in the outer plasmasphere range from near zero to +5 to +10 V. Under such conditions ion measurements may not include the low energy core of the plasma population. In eclipse, the photoelectron current drops to zero, and the spacecraft potential can drop to near zero volts. In regions where the ambient plasma density is below 100 cm -3 , previously unobserved portions of the ambient plasma distribution function can become visible in eclipse. A survey of the data obtained from the retarding ion mass spectrometer (RIMS) on Dynamics Explorer 1 shows that the RIMS detector generally measured the isotropic background in both sunlight and eclipse in the plasma-sphere. Absolute density measurements for the ''hidden'' ion population are obtained for the first time using the plasma wave instrument observations of the upper hybrid resonance. Agreement in total density is found in sunlight and eclipse measurements at densities above 80 cm -3 . In eclipse, agreement is found at densities as low as 20 cm -3 . The isotropic plasma composition is primarily H + , with approx.10% He + , and 0.1 to 1.0% O + . A low energy field-aligned ion population appears in eclipse measurements outside the plasmasphere, which is obscured in sunlight. These field-aligned ions can be interpreted as field-aligned flows with densities of a few particles per cubic centimeter, flowing at 5-20 km/s. The problem in measuring these field-aligned flows in sunlight is the masking of the high energy tail of the field-aligned distribution by the isotropic background. Effective measurement of the core of the magnetospheric plasma distribution awaits satellites with active means of controlling the satellite potential

  2. Commitment to Self-Rewards

    OpenAIRE

    Koch, Alexander K.; Nafziger, Julia

    2009-01-01

    Self-administered rewards are ubiquitous. They serve as incentives for personal accomplish¬ments and are widely recommended as tools for overcoming self-control problems. However, it seems puzzling why self-rewards can work: the prospect of a reward has a motivating force only if the threat of self-denial of the reward after low performance is credible. We explain how a rational forward-looking individual may achieve commitment to self-rewards, by applying Köszegi and Rabin's (2006) model of ...

  3. The amygdala, reward and emotion.

    Science.gov (United States)

    Murray, Elisabeth A

    2007-11-01

    Recent research provides new insights into amygdala contributions to positive emotion and reward. Studies of neuronal activity in the monkey amygdala and of autonomic responses mediated by the monkey amygdala show that, contrary to a widely held view, the amygdala is just as important for processing positive reward and reinforcement as it is for negative. In addition, neuropsychological studies reveal that the amygdala is essential for only a fraction of what might be considered 'stimulus-reward processing', and that the neural substrates for emotion and reward are partially nonoverlapping. Finally, evidence suggests that two systems within the amygdala, operating in parallel, enable reward-predicting cues to influence behavior; one mediates a general, arousing effect of reward and the other links the sensory properties of reward to emotion.

  4. Reward and punishment

    OpenAIRE

    Sigmund, Karl; Hauert, Christoph; Nowak, Martin A.

    2001-01-01

    Minigames capturing the essence of Public Goods experiments show that even in the absence of rationality assumptions, both punishment and reward will fail to bring about prosocial behavior. This result holds in particular for the well-known Ultimatum Game, which emerges as a special case. But reputation can induce fairness and cooperation in populations adapting through learning or imitation. Indeed, the inclusion of reputation effects in the corresponding dynamical models leads to the evolut...

  5. Stargate of the Hidden Multiverse

    Directory of Open Access Journals (Sweden)

    Alexander Antonov

    2016-02-01

    Full Text Available Concept of Monoverse, which corresponds to the existing broad interpretation of the second postulate of the special theory of relativity, is not consistent with the modern astrophysical reality — existence of the dark matter and the dark energy, the total mass-energy of which is ten times greater than the mass-energy of the visible universe (which has been considered as the entire universe until very recent . This concept does not allow to explain their rather unusual properties — invisibility and lack of baryon content — which would seem to even destroy the very modern understanding of the term ‘matter’. However, all numerous alternative concepts of Multiverses, which have been proposed until today, are unable to explain these properties of the dark matter and dark energy. This article describes a new concept: the concept of the hidden Multiverse and hidden Supermultiverse, which mutual invisibility of parallel universes is explained by the physical reality of imaginary numbers. This concept completely explains the phenomenon of the dark matter and the dark energy. Moreover, it is shown that the dark matter and the dark energy are the experimental evidence for the existence of the hidden Multiverse. Described structure of the hidden Multiverse is fully consistent with the data obtained by the space stations WMAP and Planck. An extremely important property of the hidden Multiverse is an actual possibility of its permeation through stargate located on the Earth.

  6. Hidden photons in connection to dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Andreas, Sarah; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Goodsell, Mark D. [CPhT, Ecole Polytechnique, Palaiseau (France)

    2013-06-15

    Light extra U(1) gauge bosons, so called hidden photons, which reside in a hidden sector have attracted much attention since they are a well motivated feature of many scenarios beyond the Standard Model and furthermore could mediate the interaction with hidden sector dark matter.We review limits on hidden photons from past electron beam dump experiments including two new limits from such experiments at KEK and Orsay. In addition, we study the possibility of having dark matter in the hidden sector. A simple toy model and different supersymmetric realisations are shown to provide viable dark matter candidates in the hidden sector that are in agreement with recent direct detection limits.

  7. Hidden photons in connection to dark matter

    International Nuclear Information System (INIS)

    Andreas, Sarah; Ringwald, Andreas; Goodsell, Mark D.

    2013-06-01

    Light extra U(1) gauge bosons, so called hidden photons, which reside in a hidden sector have attracted much attention since they are a well motivated feature of many scenarios beyond the Standard Model and furthermore could mediate the interaction with hidden sector dark matter.We review limits on hidden photons from past electron beam dump experiments including two new limits from such experiments at KEK and Orsay. In addition, we study the possibility of having dark matter in the hidden sector. A simple toy model and different supersymmetric realisations are shown to provide viable dark matter candidates in the hidden sector that are in agreement with recent direct detection limits.

  8. Temporal framing and the hidden-zero effect: rate-dependent outcomes on delay discounting.

    Science.gov (United States)

    Naudé, Gideon P; Kaplan, Brent A; Reed, Derek D; Henley, Amy J; DiGennaro Reed, Florence D

    2018-05-01

    Recent research suggests that presenting time intervals as units (e.g., days) or as specific dates, can modulate the degree to which humans discount delayed outcomes. Another framing effect involves explicitly stating that choosing a smaller-sooner reward is mutually exclusive to receiving a larger-later reward, thus presenting choices as an extended sequence. In Experiment 1, participants (N = 201) recruited from Amazon Mechanical Turk completed the Monetary Choice Questionnaire in a 2 (delay framing) by 2 (zero framing) design. Regression suggested a main effect of delay, but not zero, framing after accounting for other demographic variables and manipulations. We observed a rate-dependent effect for the date-framing group, such that those with initially steep discounting exhibited greater sensitivity to the manipulation than those with initially shallow discounting. Subsequent analyses suggest these effects cannot be explained by regression to the mean. Experiment 2 addressed the possibility that the null effect of zero framing was due to within-subject exposure to the hidden- and explicit-zero conditions. A new Amazon Mechanical Turk sample completed the Monetary Choice Questionnaire in either hidden- or explicit-zero formats. Analyses revealed a main effect of reward magnitude, but not zero framing, suggesting potential limitations to the generality of the hidden-zero effect. © 2018 Society for the Experimental Analysis of Behavior.

  9. Hidden worlds in quantum physics

    CERN Document Server

    Gouesbet, Gérard

    2014-01-01

    The past decade has witnessed a resurgence in research and interest in the areas of quantum computation and entanglement. This new book addresses the hidden worlds or variables of quantum physics. Author Gérard Gouesbet studied and worked with a former student of Louis de Broglie, a pioneer of quantum physics. His presentation emphasizes the history and philosophical foundations of physics, areas that will interest lay readers as well as professionals and advanced undergraduate and graduate students of quantum physics. The introduction is succeeded by chapters offering background on relevant concepts in classical and quantum mechanics, a brief history of causal theories, and examinations of the double solution, pilot wave, and other hidden-variables theories. Additional topics include proofs of possibility and impossibility, contextuality, non-locality, classification of hidden-variables theories, and stochastic quantum mechanics. The final section discusses how to gain a genuine understanding of quantum mec...

  10. Alleviating hidden hunger. Approaches that work

    International Nuclear Information System (INIS)

    Kennedy, E.; Mannar, V.; Iyengar, V.

    2003-01-01

    The world has come a long way in understanding the nature, magnitude and range of solutions to micronutrient malnutrition - often called 'hidden hunger'. The most sustainable solutions - that is those that are likely to be maintained in the long term - almost surely will include food-based approaches including diet diversity, food fortification and biofortification. Food fortification and biofortification could be some of the most cost-effective of all public health interventions and thus within the economic reach of even the world's poorest. In order to implement them in a sustainable manner, a combination of technical, operational, economic, behavioural and political factors need to be addressed. In some ways the technological issues are the easiest. Because of attention to research, we now have a variety of ways for both single and multiple micronutrients to reach the target population. We also know what is needed in order to ensure delivery systems. The key factor for continued success in reducing micronutrient malnutrition through fortification is a political commitment at the national and international level and creating effective public-private partnerships at the national level. The payoff for eliminating hidden hunger through nutrient fortification is enormous and few other public health interventions offer such a promising health, nutrition and economic success story. Nuclear and isotopic techniques are valuable tools in helping to meet the multifaceted challenges posed by nutritional disorders affecting the entire human life span (embryonic to elderly). Among the numerous applications available, isotopic techniques are uniquely well suited for targeting and tracking progress in food and nutrition development programmes (See box: How Nutrients are Tracked). These include: use of the stable isotopes of iron (Fe) and zinc (Zn) as a kind of gold standard in studies of their bioavailability from foods; trace element bioavailability and pool sizes for

  11. Aversive counterconditioning attenuates reward signalling in the ventral striatum

    Directory of Open Access Journals (Sweden)

    Anne Marije Kaag

    2016-08-01

    Full Text Available Appetitive conditioning refers to the process of learning cue-reward associations and is mediated by the mesocorticolimbic system. Appetitive conditioned responses are difficult to extinguish, especially for highly salient rewards such as food and drugs. We investigate whether aversive counterconditioning can alter reward reinstatement in the ventral striatum in healthy volunteers using functional Magnetic Resonance Imaging (fMRI. In the initial conditioning phase, two different stimuli were reinforced with a monetary reward. In the subsequent counterconditioning phase, one of these stimuli was paired with an aversive shock to the wrist. In the following extinction phase, none of the stimuli were reinforced. In the final reinstatement phase, reward was reinstated by informing the participants that the monetary gain could be doubled. Our fMRI data revealed that reward signalling in the ventral striatum and ventral tegmental area following reinstatement was smaller for the stimulus that was counterconditioned with an electrical shock, compared to the non-counterconditioned stimulus. A functional connectivity analysis showed that aversive counterconditioning strengthened striatal connectivity with the hippocampus and insula. These results suggest that reward signalling in the ventral striatum can be attenuated through aversive counterconditioning, possibly by concurrent retrieval of the aversive association through enhanced connectivity with hippocampus and insula.

  12. Results-based Rewards - Leveraging Wage Increases?

    DEFF Research Database (Denmark)

    Bregn, Kirsten

    2005-01-01

    A good seven years ago, as a part of a large-scale pay reform, the Danish public sector introduced results-based rewards (RBR), i.e. a pay component awarded for achieving or exceeding targets set in advance. RBR represent a possibility for combining wage-earners interests in higher wages with a g......A good seven years ago, as a part of a large-scale pay reform, the Danish public sector introduced results-based rewards (RBR), i.e. a pay component awarded for achieving or exceeding targets set in advance. RBR represent a possibility for combining wage-earners interests in higher wages...... limited use of RBR, illustrated with examples. The Danish experiences should give food for thought, given that pay systems used by the public sector are currently under transformation in practically all OECD countries....

  13. Detecting hidden particles with MATHUSLA

    Science.gov (United States)

    Evans, Jared A.

    2018-03-01

    A hidden sector containing light long-lived particles provides a well-motivated place to find new physics. The recently proposed MATHUSLA experiment has the potential to be extremely sensitive to light particles originating from rare meson decays in the very long lifetime region. In this work, we illustrate this strength with the specific example of a light scalar mixed with the standard model-like Higgs boson, a model where MATHUSLA can further probe unexplored parameter space from exotic Higgs decays. Design augmentations should be considered in order to maximize the ability of MATHUSLA to discover very light hidden sector particles.

  14. Risk, reward, and decision-making in a rodent model of cognitive aging.

    Science.gov (United States)

    Gilbert, Ryan J; Mitchell, Marci R; Simon, Nicholas W; Bañuelos, Cristina; Setlow, Barry; Bizon, Jennifer L

    2011-01-01

    Impaired decision-making in aging can directly impact factors (financial security, health care) that are critical to maintaining quality of life and independence at advanced ages. Naturalistic rodent models mimic human aging in other cognitive domains, and afford the opportunity to parse the effects of age on discrete aspects of decision-making in a manner relatively uncontaminated by experiential factors. Young adult (5-7 months) and aged (23-25 months) male F344 rats were trained on a probability discounting task in which they made discrete-trial choices between a small certain reward (one food pellet) and a large but uncertain reward (two food pellets with varying probabilities of delivery ranging from 100 to 0%). Young rats chose the large reward when it was associated with a high probability of delivery and shifted to the small but certain reward as probability of the large reward decreased. As a group, aged rats performed comparably to young, but there was significantly greater variance among aged rats. One subgroup of aged rats showed strong preference for the small certain reward. This preference was maintained under conditions in which large reward delivery was also certain, suggesting decreased sensitivity to reward magnitude. In contrast, another subgroup of aged rats showed strong preference for the large reward at low probabilities of delivery. Interestingly, this subgroup also showed elevated preference for probabilistic rewards when reward magnitudes were equalized. Previous findings using this same aged study population described strongly attenuated discounting of delayed rewards with age, together suggesting that a subgroup of aged rats may have deficits associated with accounting for reward costs (i.e., delay or probability). These deficits in cost-accounting were dissociable from the age-related differences in sensitivity to reward magnitude, suggesting that aging influences multiple, distinct mechanisms that can impact cost-benefit decision-making.

  15. Hidden Crises and Communication: An Interactional Analysis of Hidden Crises

    NARCIS (Netherlands)

    dr. Annette Klarenbeek

    2011-01-01

    In this paper I describe the ways in which the communication discipline can make a hidden crisis transparent. For this purpose I examine the concept of crisis entrepreneurship from a communication point of view. Using discourse analysis, I analyse the discursive practices of crisis entrepreneurs in

  16. Hidden Crises and Communication : An Interactional Analysis of Hidden Crises

    NARCIS (Netherlands)

    dr. Annette Klarenbeek

    2011-01-01

    In this paper I describe the ways in which the communication discipline can make a hidden crisis transparent. For this purpose I examine the concept of crisis entrepreneurship from a communication point of view. Using discourse analysis, I analyse the discursive practices of crisis entrepreneurs in

  17. A balance of activity in brain control and reward systems predicts self-regulatory outcomes

    OpenAIRE

    Lopez, Richard B.; Chen, Pin-Hao A.; Huckins, Jeremy F.; Hofmann, Wilhelm; Kelley, William M.; Heatherton, Todd F.

    2017-01-01

    Abstract Previous neuroimaging work has shown that increased reward-related activity following exposure to food cues is predictive of self-control failure. The balance model suggests that self-regulation failures result from an imbalance in reward and executive control mechanisms. However, an open question is whether the relative balance of activity in brain systems associated with executive control (vs reward) supports self-regulatory outcomes when people encounter tempting cues in daily lif...

  18. Food advertising and eating behavior in children

    NARCIS (Netherlands)

    Folkvord, F.; Anschutz, D.J.; Boyland, E.J.; Kelly, B.; Buijzen, M.A.

    2016-01-01

    Systematic research reviews have repeatedly shown that food advertising affects children's eating behavior. Given that most food advertising promotes unhealthy, palatable, and rewarding food products, it is considered to be a significant contributor to the current obesity epidemic. This review

  19. Monetary rewards modulate inhibitory control

    Directory of Open Access Journals (Sweden)

    Paula Marcela Herrera

    2014-05-01

    Full Text Available The ability to override a dominant response, often referred to as behavioural inhibiton, is considered a key element of executive cognition. Poor behavioural inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioural inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/Nogo and Stop Signal Tasks. Several studies have reported a positive modulatory effect of reward on the performance of such tasks in pathological conditions such as substance abuse, pathological gambling, and ADHD. However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory paradigms are rare and consequently, little is known about the finer grained relationship between motivation and self-control. Here, we probed the effect of reward and reward magnitude on behavioural inhibition using two modified version of the widely used Stop Signal Task. The first task compared no reward with reward, whilst the other compared two different reward magnitudes. The reward magnitude effect was confirmed by the second study, whereas it was less compelling in the first study, possibly due to the effect of having no reward in some conditions. In addition, our results showed a kick start effect over global performance measures. More specifically, there was a long lasting improvement in performance throughout the task, when participants received the highest reward magnitudes at the beginning of the protocol. These results demonstrate that individuals’ behavioural inhibition capacities are dynamic not static because they are modulated by the reward magnitude and initial reward history of the task at hand.

  20. Impaired reward responsiveness in schizophrenia.

    Science.gov (United States)

    Taylor, Nicholas; Hollis, Jeffrey P; Corcoran, Sarah; Gross, Robin; Cuthbert, Bruce; Swails, Lisette W; Duncan, Erica

    2018-03-08

    Anhedonia is a core negative symptom of schizophrenia. Schizophrenia patients report largely intact pleasure in consuming rewards, but have impairments in generating motivated behavior to pursue rewards, and show reduced fMRI activation of the reward pathway during presentation of rewarded stimuli. A computer based task measuring the development of a response bias in favor of rewarded stimuli permits assessment of reward-induced motivation. We hypothesized that subjects with schizophrenia would be impaired on this task. 58 schizophrenia subjects (SCZ) and 52 healthy controls (CON) were studied with a signal detection task to assess reward responsiveness. In multiple trials over three blocks subjects were asked to correctly identify two stimuli that were paired with unequal chance of monetary reward. The critical outcome variable was response bias, the development of a greater percent correct identification of the stimulus that was rewarded more often. An ANOVA on response bias with Block as a repeated-measures factor and Diagnosis as a between-group factor indicated that SCZ subjects achieved a lower bias to rewarded stimuli than CON subjects (F(1,105)=8.82, p=0.004, η 2 =0.078). Post hoc tests indicated that SCZ subjects had significantly impaired bias in Block 1 (p=0.002) and Block 2 (p=0.05), indicating that SCZ were slower to achieve normal levels of bias during the session. SCZ subjects were slower to develop response bias to rewarded stimuli than CON subjects. This finding is consonant with the hypothesis that people with schizophrenia have a blunted capacity to modify behavior in response to reward. Copyright © 2018. Published by Elsevier B.V.

  1. A Fly’s Eye View of Natural and Drug Reward

    Science.gov (United States)

    Lowenstein, Eve G.; Velazquez-Ulloa, Norma A.

    2018-01-01

    Animals encounter multiple stimuli each day. Some of these stimuli are innately appetitive or aversive, while others are assigned valence based on experience. Drugs like ethanol can elicit aversion in the short term and attraction in the long term. The reward system encodes the predictive value for different stimuli, mediating anticipation for attractive or punishing stimuli and driving animal behavior to approach or avoid conditioned stimuli. The neurochemistry and neurocircuitry of the reward system is partly evolutionarily conserved. In both vertebrates and invertebrates, including Drosophila melanogaster, dopamine is at the center of a network of neurotransmitters and neuromodulators acting in concert to encode rewards. Behavioral assays in D. melanogaster have become increasingly sophisticated, allowing more direct comparison with mammalian research. Moreover, recent evidence has established the functional modularity of the reward neural circuits in Drosophila. This functional modularity resembles the organization of reward circuits in mammals. The powerful genetic and molecular tools for D. melanogaster allow characterization and manipulation at the single-cell level. These tools are being used to construct a detailed map of the neural circuits mediating specific rewarding stimuli and have allowed for the identification of multiple genes and molecular pathways that mediate the effects of reinforcing stimuli, including their rewarding effects. This report provides an overview of the research on natural and drug reward in D. melanogaster, including natural rewards such as sugar and other food nutrients, and drug rewards including ethanol, cocaine, amphetamine, methamphetamine, and nicotine. We focused mainly on the known genetic and neural mechanisms underlying appetitive reward for sugar and reward for ethanol. We also include genes, molecular pathways, and neural circuits that have been identified using assays that test the palatability of the rewarding

  2. Palatable Food Consumption in Children

    DEFF Research Database (Denmark)

    De Decker, Annelies; Verbeken, Sandra; Sioen, Isabelle

    2017-01-01

    To understand the importance of the home food environment on unhealthy food consumption in children high in reward sensitivity, this study tested the hypothesis that the home availability of unhealthy food moderates the effect of reward sensitivity on children’s fast-food consumption frequency......, exerted via food cue responsiveness. Children between 7.5 and 14 years (n = 174, 50.6% boys) reported on reward sensitivity and food cue responsiveness (by means of the subscale ‘external eating’). Their height and weight were measured. Parents reported on their children’s fast-food consumption frequency......, food cue responsiveness (by means of the subscale ‘food responsiveness’), and on the home availability of unhealthy foods. Two moderated mediation models were conducted, one with the parent- and one with the child-reported food cue responsiveness as mediator. Findings suggested that with a high home...

  3. Commitment to self-rewards

    DEFF Research Database (Denmark)

    Koch, Alexander; Nafziger, Julia

    People often overcome self-control problems by promising to reward themselves for accomplishing a task. Such strategies based on self-administered rewards however require the person to believe that she would indeed deny herself the reward if she should fail to achieve the desired outcome. Drawing...... on Koszegi and Rabin's (2006) model of endogenous reference point formation, we show how a rational forward-looking individual can achieve such internal commitment. But our results also demonstrate the limitations of self regulation based on self-rewards....

  4. Entry deterrence and hidden competition

    NARCIS (Netherlands)

    Lavrutich, Maria; Huisman, Kuno; Kort, Peter

    This paper studies strategic investment behavior of firms facing an uncertain demand in a duopoly setting. Firms choose both investment timing and the capacity level while facing additional uncertainty about market participants, which is introduced via the concept of hidden competition. We focus on

  5. Adaptive Partially Hidden Markov Models

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Rasmussen, Tage

    1996-01-01

    Partially Hidden Markov Models (PHMM) have recently been introduced. The transition and emission probabilities are conditioned on the past. In this report, the PHMM is extended with a multiple token version. The different versions of the PHMM are applied to bi-level image coding....

  6. The Hidden Dimensions of Databases.

    Science.gov (United States)

    Jacso, Peter

    1994-01-01

    Discusses methods of evaluating commercial online databases and provides examples that illustrate their hidden dimensions. Topics addressed include size, including the number of records or the number of titles; the number of years covered; and the frequency of updates. Comparisons of Readers' Guide Abstracts and Magazine Article Summaries are…

  7. Reward sensitivity predicts ice cream-related attentional bias assessed by inattentional blindness.

    Science.gov (United States)

    Li, Xiaoming; Tao, Qian; Fang, Ya; Cheng, Chen; Hao, Yangyang; Qi, Jianjun; Li, Yu; Zhang, Wei; Wang, Ying; Zhang, Xiaochu

    2015-06-01

    The cognitive mechanism underlying the association between individual differences in reward sensitivity and food craving is unknown. The present study explored the mechanism by examining the role of reward sensitivity in attentional bias toward ice cream cues. Forty-nine college students who displayed high level of ice cream craving (HICs) and 46 who displayed low level of ice cream craving (LICs) performed an inattentional blindness (IB) task which was used to assess attentional bias for ice cream. In addition, reward sensitivity and coping style were assessed by the Behavior Inhibition System/Behavior Activation System Scales and Simplified Coping Style Questionnaire. Results showed significant higher identification rate of the critical stimulus in the HICs than LICs, suggesting greater attentional bias for ice cream in the HICs. It was indicated that attentional bias for food cues persisted even under inattentional condition. Furthermore, a significant correlation was found between the attentional bias and reward sensitivity after controlling for coping style, and reward sensitivity predicted attentional bias for food cues. The mediation analyses showed that attentional bias mediated the relationship between reward sensitivity and food craving. Those findings suggest that the association between individual differences in reward sensitivity and food craving may be attributed to attentional bias for food-related cues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Multi-layer network utilizing rewarded spike time dependent plasticity to learn a foraging task.

    Directory of Open Access Journals (Sweden)

    Pavel Sanda

    2017-09-01

    Full Text Available Neural networks with a single plastic layer employing reward modulated spike time dependent plasticity (STDP are capable of learning simple foraging tasks. Here we demonstrate advanced pattern discrimination and continuous learning in a network of spiking neurons with multiple plastic layers. The network utilized both reward modulated and non-reward modulated STDP and implemented multiple mechanisms for homeostatic regulation of synaptic efficacy, including heterosynaptic plasticity, gain control, output balancing, activity normalization of rewarded STDP and hard limits on synaptic strength. We found that addition of a hidden layer of neurons employing non-rewarded STDP created neurons that responded to the specific combinations of inputs and thus performed basic classification of the input patterns. When combined with a following layer of neurons implementing rewarded STDP, the network was able to learn, despite the absence of labeled training data, discrimination between rewarding patterns and the patterns designated as punishing. Synaptic noise allowed for trial-and-error learning that helped to identify the goal-oriented strategies which were effective in task solving. The study predicts a critical set of properties of the spiking neuronal network with STDP that was sufficient to solve a complex foraging task involving pattern classification and decision making.

  9. Monetary rewards influence retrieval orientations.

    Science.gov (United States)

    Halsband, Teresa M; Ferdinand, Nicola K; Bridger, Emma K; Mecklinger, Axel

    2012-09-01

    Reward anticipation during learning is known to support memory formation, but its role in retrieval processes is so far unclear. Retrieval orientations, as a reflection of controlled retrieval processing, are one aspect of retrieval that might be modulated by reward. These processes can be measured using the event-related potentials (ERPs) elicited by retrieval cues from tasks with different retrieval requirements, such as via changes in the class of targeted memory information. To determine whether retrieval orientations of this kind are modulated by reward during learning, we investigated the effects of high and low reward expectancy on the ERP correlates of retrieval orientation in two separate experiments. The reward manipulation at study in Experiment 1 was associated with later memory performance, whereas in Experiment 2, reward was directly linked to accuracy in the study task. In both studies, the participants encoded mixed lists of pictures and words preceded by high- or low-reward cues. After 24 h, they performed a recognition memory exclusion task, with words as the test items. In addition to a previously reported material-specific effect of retrieval orientation, a frontally distributed, reward-associated retrieval orientation effect was found in both experiments. These findings suggest that reward motivation during learning leads to the adoption of a reward-associated retrieval orientation to support the retrieval of highly motivational information. Thus, ERP retrieval orientation effects not only reflect retrieval processes related to the sought-for materials, but also relate to the reward conditions with which items were combined during encoding.

  10. Risk, reward, and decision-making in a rodent model of cognitive aging

    Directory of Open Access Journals (Sweden)

    Ryan J Gilbert

    2012-01-01

    Full Text Available Impaired decision-making in aging can directly impact factors (financial security, quality of healthcare that are critical to maintaining quality of life and independence at advanced ages. Naturalistic rodent models mimic human aging in other cognitive domains, and afford the opportunity to parse the effects of age on discrete aspects of decision-making in a manner relatively uncontaminated by experiential factors. Young adult (5-7 mo. and aged (23-25 mo. male F344 rats were trained on a probability discounting task in which they made discrete-trial choices between a small certain reward (1 food pellet and a large but uncertain reward (2 food pellets with varying probabilities of delivery ranging from 100% to 0%. Young rats chose the large reward when it was associated with a high probability of delivery and shifted to the smaller but certain reward as probability of the large reward decreased. As a group, aged rats performed comparably to young, but there was significantly greater variance among aged rats. One subgroup of aged rats showed strong preference for the small certain reward. This preference was maintained under conditions in which large reward delivery was certain, suggesting decreased sensitivity to reward magnitude. In contrast, another subgroup of aged rats showed strong preference for the large reward at low probabilities of delivery. Interestingly, this subgroup also showed elevated preference for probabilistic rewards when reward magnitudes were equalized. Previous findings using this same aged study population described strongly attenuated discounting of delayed rewards with age, together suggesting that a subgroup of aged rats may have deficits associated with accounting for costs (i.e., delay, probability. These deficits in cost-accounting were dissociable from the age-related differences in sensitivity to reward magnitude, suggesting that aging influences multiple, distinct neural mechanisms that can impact cost

  11. Molecular role of dopamine in anhedonia linked to reward deficiency syndrome (RDS) and anti- reward systems.

    Science.gov (United States)

    Gold, Mark S; Blum, Kenneth; Febo, Marcelo; Baron, David; Modestino, Edward Justin; Elman, Igor; Badgaiyan, Rajendra D

    2018-03-01

    Anhedonia is a condition that leads to the loss of feelings pleasure in response to natural reinforcers like food, sex, exercise, and social activities. This disorder occurs in addiction, and an array of related neuropsychiatric syndromes, including schizophrenia, depression, and Post Traumatic Stress Disorder (PTSD). Anhedonia may by due to derangements in mesolimbic dopaminergic pathways and their terminal fields (e.g., striatum, amygdala, and prefrontal cortex) that persist long after the traces of the causative drugs are eliminated (pharmacokinetically). Here we postulate that anhedonia is not a distinct entity but is rather an epiphenomenon of hypodopaminergic states and traits arising from the interaction of genetic traits and epigenetic neurobiological alterations in response to environmental influences. Moreover, dopaminergic activity is rather complex, and so it may give rise to differential pathophysiological processes such as incentive sensitization, aberrant learning and stress-like "anti-reward" phenomena. These processes may have additive, synergistic or antagonistic interactions with the concurrent reward deficiency states leading in some instances to more severe and long-lasting symptoms. Operant understanding of the neurogenetic antecedents to reward deficiency syndrome (RDS) and the elucidation of reward gene polymorphisms may provide a map for accessing an individual's genetic risk for developing Anhedonia. Prevention techniques that can restore homeostatic balance via physiological activation of dopaminergic receptors (D2/D3) may be instrumental for targeting not only anhedonia per se but also drug craving and relapse.

  12. Model Checking Multivariate State Rewards

    DEFF Research Database (Denmark)

    Nielsen, Bo Friis; Nielson, Flemming; Nielson, Hanne Riis

    2010-01-01

    We consider continuous stochastic logics with state rewards that are interpreted over continuous time Markov chains. We show how results from multivariate phase type distributions can be used to obtain higher-order moments for multivariate state rewards (including covariance). We also generalise...

  13. Increased Capacity to Delay Reward in Anorexia Nervosa

    NARCIS (Netherlands)

    Steinglass, J.E.; Figner, B.; Berkowitz, S.; Simpson, H.B.; Weber, E.U.; Walsh, B.T.

    2012-01-01

    Individuals with anorexia nervosa (AN) are often characterized as possessing excessive self-control and are unusual in their ability to reduce or avoid the consumption of palatable foods. This behavior promotes potentially life-threatening weight loss and suggests disturbances in reward processing.

  14. Rats prefer mutual rewards in a prosocial choice task.

    Science.gov (United States)

    Hernandez-Lallement, Julen; van Wingerden, Marijn; Marx, Christine; Srejic, Milan; Kalenscher, Tobias

    2014-01-01

    Pro-sociality, i.e., the preference for outcomes that produce benefits for other individuals, is ubiquitous in humans. Recently, cross-species comparisons of social behavior have offered important new insights into the evolution of pro-sociality. Here, we present a rodent analog of the Pro-social Choice Task that controls strategic components, de-confounds other-regarding choice motives from the animals' natural tendencies to maximize own food access and directly tests the effect of social context on choice allocation. We trained pairs of rats-an actor and a partner rat-in a double T-maze task where actors decided between two alternatives only differing in the reward delivered to the partner. The "own reward" choice yielded a reward only accessible to the actor whereas the "both reward" choice produced an additional reward for a partner (partner condition) or an inanimate toy (toy Condition), located in an adjacent compartment. We found that actors chose "both reward" at levels above chance and more often in the partner than in the toy condition. Moreover, we show that this choice pattern adapts to the current social context and that the observed behavior is stable over time.

  15. Risk and reward

    International Nuclear Information System (INIS)

    Kellas, G.K.; Hodgshon, S.G.

    1992-01-01

    This paper looks at the problems facing the international oil explorationist and host Governments in 1992, under a cloud of low oil prices and falling company profits, yet with more quality acreage available worldwide than for many years, especially with the emergence of the CIS states as prospective hunting grounds for the western oil company. Given the extent of the spread of opportunities available to companies and recognition of the increasing need to justify, on economic grounds, progress with any licence application this paper suggests two approaches that companies can adopt to rank the opportunities available, and maximize the value, on an after risk basis, of their (limited) international exploration budget : subjective rating by factor or the Risk/Reward balance. Both of these approaches include measures of prospectivity and measures of local cost and fiscal effects in providing an overall exploration rating which can be used by companies to rank the available opportunities

  16. ATLAS rewards industry

    CERN Multimedia

    2006-01-01

    Showing excellence in mechanics, electronics and cryogenics, three industries are honoured for their contributions to the ATLAS experiment. Representatives of the three award-wining companies after the ceremony. For contributing vital pieces to the ATLAS puzzle, three industries were recognized on Friday 5 May during a supplier awards ceremony. After a welcome and overview of the ATLAS experiment by spokesperson Peter Jenni, CERN Secretary-General Maximilian Metzger stressed the importance of industry to CERN's scientific goals. Close interaction with CERN was a key factor in the selection of each rewarded company, in addition to the high-quality products they delivered to the experiment. Alu Menziken Industrie AG, of Switzerland, was honoured for the production of 380,000 aluminium tubes for the Monitored Drift Tube Chambers (MDT). As Giora Mikenberg, the Muon System Project Leader stressed, the aluminium tubes were delivered on time with an extraordinary quality and precision. Between October 2000 and Jan...

  17. Reward deficiency and anti-reward in pain chronification.

    Science.gov (United States)

    Borsook, D; Linnman, C; Faria, V; Strassman, A M; Becerra, L; Elman, I

    2016-09-01

    Converging lines of evidence suggest that the pathophysiology of pain is mediated to a substantial degree via allostatic neuroadaptations in reward- and stress-related brain circuits. Thus, reward deficiency (RD) represents a within-system neuroadaptation to pain-induced protracted activation of the reward circuits that leads to depletion-like hypodopaminergia, clinically manifested anhedonia, and diminished motivation for natural reinforcers. Anti-reward (AR) conversely pertains to a between-systems neuroadaptation involving over-recruitment of key limbic structures (e.g., the central and basolateral amygdala nuclei, the bed nucleus of the stria terminalis, the lateral tegmental noradrenergic nuclei of the brain stem, the hippocampus and the habenula) responsible for massive outpouring of stressogenic neurochemicals (e.g., norepinephrine, corticotropin releasing factor, vasopressin, hypocretin, and substance P) giving rise to such negative affective states as anxiety, fear and depression. We propose here the Combined Reward deficiency and Anti-reward Model (CReAM), in which biopsychosocial variables modulating brain reward, motivation and stress functions can interact in a 'downward spiral' fashion to exacerbate the intensity, chronicity and comorbidities of chronic pain syndromes (i.e., pain chronification). Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Ghrelin at the interface of obesity and reward.

    Science.gov (United States)

    Schellekens, Harriët; Dinan, Timothy G; Cryan, John F

    2013-01-01

    The prevalence of obesity continues to increase and has reached epidemic proportions. Accumulating data over the past few decades have given us key insights and broadened our understanding of the peripheral and central regulation of energy homeostasis. Despite this, the currently available pharmacological treatments, reducing body weight, remain limited due to poor efficacy and side effects. The gastric peptide ghrelin has been identified as the only orexigenic hormone from the periphery to act in the hypothalamus to stimulate food intake. Recently, a role for ghrelin and its receptor at the interface between homeostatic control of appetite and reward circuitries modulating the hedonic aspects of food has also emerged. Nonhomeostatic factors such as the rewarding and motivational value of food, which increase with food palatability and caloric content, can override homeostatic control of food intake. This nonhomeostatic decision to eat leads to overconsumption beyond nutritional needs and is being recognized as a key component in the underlying causes for the increase in obesity incidence worldwide. In addition, the hedonic feeding behavior has been linked to food addiction and an important role for ghrelin in the development of addiction has been suggested. Moreover, plasma ghrelin levels are responsive to conditions of stress, and recent evidence has implicated ghrelin in stress-induced food-reward behavior. The prominent role of the ghrelinergic system in the regulation of feeding gives rise to it as an effective target for the development of successful antiobesity pharmacotherapies that not only affect satiety but also selectively modulate the rewarding properties of food and reduce the desire to eat. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Hidden supersymmetry and large N

    International Nuclear Information System (INIS)

    Alfaro, J.

    1988-01-01

    In this paper we present a new method to deal with the leading order in the large-N expansion of a quantum field theory. The method uses explicitly the hidden supersymmetry that is present in the path-integral formulation of a stochastic process. In addition to this we derive a new relation that is valid in the leading order of the large-N expansion of the hermitian-matrix model for any spacetime dimension. (orig.)

  20. Optogenetic excitation of central amygdala amplifies and narrows incentive motivation to pursue one reward above another.

    Science.gov (United States)

    Robinson, Mike J F; Warlow, Shelley M; Berridge, Kent C

    2014-12-10

    Choosing one reward above another is important for achieving adaptive life goals. Yet hijacked into excessive intensity in disorders such as addiction, single-minded pursuit becomes maladaptive. Here, we report that optogenetic channelrhodopsin stimulation of neurons in central nucleus of amygdala (CeA), paired with earning a particular sucrose reward in rats, amplified and narrowed incentive motivation to that single reward target. Therefore, CeA rats chose and intensely pursued only the laser-paired sucrose reward while ignoring an equally good sucrose alternative. In contrast, reward-paired stimulation of basolateral amygdala did not hijack choice. In a separate measure of incentive motivation, CeA stimulation also increased the progressive ratio breakpoint or level of effort exerted to obtain sucrose reward. However, CeA stimulation by itself failed to support behavioral self-stimulation in the absence of any paired external food reward, suggesting that CeA photo-excitation specifically transformed the value of its external reward (rather than adding an internal reinforcement state). Nor did CeA stimulation by itself induce any aversive state that motivated escape. Finally, CeA stimulation also failed to enhance 'liking' reactions elicited by sucrose taste and did not simply increase the general motivation to eat. This pattern suggests that CeA photo-excitation specifically enhances and narrows incentive motivation to pursue an associated external reward at the expense of another comparable reward. Copyright © 2014 the authors 0270-6474/14/3416567-14$15.00/0.

  1. Hunger does not motivate reward in women remitted from anorexia nervosa.

    Science.gov (United States)

    Wierenga, Christina E; Bischoff-Grethe, Amanda; Melrose, A James; Irvine, Zoe; Torres, Laura; Bailer, Ursula F; Simmons, Alan; Fudge, Julie L; McClure, Samuel M; Ely, Alice; Kaye, Walter H

    2015-04-01

    Hunger enhances sensitivity to reward, yet individuals with anorexia nervosa (AN) are not motivated to eat when starved. This study investigated brain response to rewards during hunger and satiated states to examine whether diminished response to reward could underlie food restriction in AN. Using a delay discounting monetary decision task known to discriminate brain regions contributing to processing of immediate rewards and cognitive control important for decision making regarding future rewards, we compared 23 women remitted from AN (RAN group; to reduce the confounding effects of starvation) with 17 healthy comparison women (CW group). Monetary rewards were used because the rewarding value of food may be confounded by anxiety in AN. Interactions of Group (RAN, CW) × Visit (hunger, satiety) revealed that, for the CW group, hunger significantly increased activation in reward salience circuitry (ventral striatum, dorsal caudate, anterior cingulate cortex) during processing of immediate reward, whereas satiety increased activation in cognitive control circuitry (ventrolateral prefrontal cortex, insula) during decision making. In contrast, brain response in reward and cognitive neurocircuitry did not differ during hunger and satiety in the RAN group. A main effect of group revealed elevated response in the middle frontal gyrus for the RAN group compared with the CW group. Women remitted from AN failed to increase activation of reward valuation circuitry when hungry and showed elevated response in cognitive control circuitry independent of metabolic state. Decreased sensitivity to the motivational drive of hunger may explain the ability of individuals with AN to restrict food when emaciated. Difficulties in valuating emotional salience may contribute to inabilities to appreciate the risks inherent in this disorder. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  2. Employee Reward Systems in Organizations

    Directory of Open Access Journals (Sweden)

    Došenović Dragana

    2016-06-01

    Full Text Available Employee rewarding is one of the activities of human resource management concerning the management of money, goods and services that employees receive from their employer in exchange for their work. Given that a properly designed reward system is one of the conditions for a stable business, successful performance of work activities and the achievement of set objectives in each organization, the basic theme of this paper is the employee reward system, with a special focus on different elements of it. The purpose of this paper is to describe the role and significance of the observed system and to draw attention to its role in employee’s motivation.

  3. Mood, food, and obesity

    Directory of Open Access Journals (Sweden)

    Minati eSingh

    2014-09-01

    Full Text Available Food is a potent natural reward and food intake is a complex process. Reward and gratification associated with food consumption leads to dopamine (DA production, which in turn activates reward and pleasure centers in the brain. An individual will repeatedly eat a particular food to experience this positive feeling of gratification. This type of repetitive behavior of food intake leads to the activation of brain reward pathways that eventually overrides other signals of satiety and hunger. Thus, a gratification habit through a favorable food leads to overeating and morbid obesity. Overeating and obesity stems from many biological factors engaging both central and peripheral systems in a bi-directional manner involving mood and emotions. Emotional eating and altered mood can also lead to altered food choice and intake leading to overeating and obesity. Research findings from human and animal studies support a two-way link between three concepts, mood, food, and obesity. The focus of this article is to provide an overview of complex nature of food intake where various biological factors link mood, food intake, and brain signaling that engages both peripheral and central nervous system signaling pathways in a bi-directional manner in obesity.

  4. Mood, food, and obesity.

    Science.gov (United States)

    Singh, Minati

    2014-01-01

    Food is a potent natural reward and food intake is a complex process. Reward and gratification associated with food consumption leads to dopamine (DA) production, which in turn activates reward and pleasure centers in the brain. An individual will repeatedly eat a particular food to experience this positive feeling of gratification. This type of repetitive behavior of food intake leads to the activation of brain reward pathways that eventually overrides other signals of satiety and hunger. Thus, a gratification habit through a favorable food leads to overeating and morbid obesity. Overeating and obesity stems from many biological factors engaging both central and peripheral systems in a bi-directional manner involving mood and emotions. Emotional eating and altered mood can also lead to altered food choice and intake leading to overeating and obesity. Research findings from human and animal studies support a two-way link between three concepts, mood, food, and obesity. The focus of this article is to provide an overview of complex nature of food intake where various biological factors link mood, food intake, and brain signaling that engages both peripheral and central nervous system signaling pathways in a bi-directional manner in obesity.

  5. Mood, food, and obesity

    Science.gov (United States)

    Singh, Minati

    2014-01-01

    Food is a potent natural reward and food intake is a complex process. Reward and gratification associated with food consumption leads to dopamine (DA) production, which in turn activates reward and pleasure centers in the brain. An individual will repeatedly eat a particular food to experience this positive feeling of gratification. This type of repetitive behavior of food intake leads to the activation of brain reward pathways that eventually overrides other signals of satiety and hunger. Thus, a gratification habit through a favorable food leads to overeating and morbid obesity. Overeating and obesity stems from many biological factors engaging both central and peripheral systems in a bi-directional manner involving mood and emotions. Emotional eating and altered mood can also lead to altered food choice and intake leading to overeating and obesity. Research findings from human and animal studies support a two-way link between three concepts, mood, food, and obesity. The focus of this article is to provide an overview of complex nature of food intake where various biological factors link mood, food intake, and brain signaling that engages both peripheral and central nervous system signaling pathways in a bi-directional manner in obesity. PMID:25225489

  6. Hidden particle production at the ILC

    International Nuclear Information System (INIS)

    Fujii, Keisuke; Itoh, Hideo; Okada, Nobuchika; Hano, Hitoshi; Yoshioka, Tamaki

    2008-01-01

    In a class of new physics models, the new physics sector is completely or partly hidden, namely, a singlet under the standard model (SM) gauge group. Hidden fields included in such new physics models communicate with the standard model sector through higher-dimensional operators. If a cutoff lies in the TeV range, such hidden fields can be produced at future colliders. We consider a scalar field as an example of the hidden fields. Collider phenomenology on this hidden scalar is similar to that of the SM Higgs boson, but there are several features quite different from those of the Higgs boson. We investigate productions of the hidden scalar at the International Linear Collider (ILC) and study the feasibility of its measurements, in particular, how well the ILC distinguishes the scalar from the Higgs boson, through realistic Monte Carlo simulations.

  7. Reward components of feeding behavior are preserved during mouse aging

    Directory of Open Access Journals (Sweden)

    Mazen R. Harb

    2014-09-01

    Full Text Available Eating behavior depends on associations between the sensory and energetic properties of foods. Healthful balance of these factors is a challenge for industrialized societies that have an abundance of food, food choices and food-related cues. Here, we were interested in whether appetitive conditioning changes as a function of age. Operant and pavlovian conditioning experiments (rewarding stimulus was a palatable food in male mice (aged 3, 6 and 15 months showed that implicit (non-declarative memory remains intact during aging. Two other essential components of eating behavior, motivation and hedonic preference for rewarding foods, were also found not to be altered in aging mice. Specifically, hedonic responding by satiated mice to isocaloric foods of differing sensory properties (sucrose, milk was similar in all age groups; importantly, however, this paradigm disclosed that older animals adjust their energy intake according to energetic need. Based on the assumption that the mechanisms that control feeding are conserved across species, it would appear that overeating and obesity in humans reflects a mismatch between ancient physiological mechanisms and today’s cue-laden environment. The implication of the present results showing that aging does not impair the ability to learn stimulus-food associations is that the risk of overeating in response to food cues is maintained through to old age.

  8. Reward components of feeding behavior are preserved during mouse aging.

    Science.gov (United States)

    Harb, Mazen R; Sousa, Nuno; Zihl, Joseph; Almeida, Osborne F X

    2014-01-01

    Eating behavior depends on associations between the sensory and energetic properties of foods. Healthful balance of these factors is a challenge for industrialized societies that have an abundance of food, food choices and food-related cues. Here, we were interested in whether appetitive conditioning changes as a function of age. Operant and pavlovian conditioning experiments (rewarding stimulus was a palatable food) in male mice (aged 3, 6, and 15 months) showed that implicit (non-declarative) memory remains intact during aging. Two other essential components of eating behavior, motivation and hedonic preference for rewarding foods, were also found not to be altered in aging mice. Specifically, hedonic responding by satiated mice to isocaloric foods of differing sensory properties (sucrose, milk) was similar in all age groups; importantly, however, this paradigm disclosed that older animals adjust their energy intake according to energetic need. Based on the assumption that the mechanisms that control feeding are conserved across species, it would appear that overeating and obesity in humans reflects a mismatch between ancient physiological mechanisms and today's cue-laden environment. The implication of the present results showing that aging does not impair the ability to learn stimulus-food associations is that the risk of overeating in response to food cues is maintained through to old age.

  9. Random reward priming is task-contingent

    DEFF Research Database (Denmark)

    Ásgeirsson, Árni Gunnar; Kristjánsson, Árni

    2014-01-01

    Consistent financial reward of particular features influences the allocation of visual attention in many ways. More surprising are 1-trial reward priming effects on attention where reward schedules are random and reward on one trial influences attentional allocation on the next. Those findings...

  10. Hidden measurements, hidden variables and the volume representation of transition probabilities

    OpenAIRE

    Oliynyk, Todd A.

    2005-01-01

    We construct, for any finite dimension $n$, a new hidden measurement model for quantum mechanics based on representing quantum transition probabilities by the volume of regions in projective Hilbert space. For $n=2$ our model is equivalent to the Aerts sphere model and serves as a generalization of it for dimensions $n \\geq 3$. We also show how to construct a hidden variables scheme based on hidden measurements and we discuss how joint distributions arise in our hidden variables scheme and th...

  11. Dissipative hidden sector dark matter

    Science.gov (United States)

    Foot, R.; Vagnozzi, S.

    2015-01-01

    A simple way of explaining dark matter without modifying known Standard Model physics is to require the existence of a hidden (dark) sector, which interacts with the visible one predominantly via gravity. We consider a hidden sector containing two stable particles charged under an unbroken U (1 )' gauge symmetry, hence featuring dissipative interactions. The massless gauge field associated with this symmetry, the dark photon, can interact via kinetic mixing with the ordinary photon. In fact, such an interaction of strength ε ˜10-9 appears to be necessary in order to explain galactic structure. We calculate the effect of this new physics on big bang nucleosynthesis and its contribution to the relativistic energy density at hydrogen recombination. We then examine the process of dark recombination, during which neutral dark states are formed, which is important for large-scale structure formation. Galactic structure is considered next, focusing on spiral and irregular galaxies. For these galaxies we modeled the dark matter halo (at the current epoch) as a dissipative plasma of dark matter particles, where the energy lost due to dissipation is compensated by the energy produced from ordinary supernovae (the core-collapse energy is transferred to the hidden sector via kinetic mixing induced processes in the supernova core). We find that such a dynamical halo model can reproduce several observed features of disk galaxies, including the cored density profile and the Tully-Fisher relation. We also discuss how elliptical and dwarf spheroidal galaxies could fit into this picture. Finally, these analyses are combined to set bounds on the parameter space of our model, which can serve as a guideline for future experimental searches.

  12. Premotor and Motor Cortices Encode Reward.

    Directory of Open Access Journals (Sweden)

    Pavan Ramkumar

    Full Text Available Rewards associated with actions are critical for motivation and learning about the consequences of one's actions on the world. The motor cortices are involved in planning and executing movements, but it is unclear whether they encode reward over and above limb kinematics and dynamics. Here, we report a categorical reward signal in dorsal premotor (PMd and primary motor (M1 neurons that corresponds to an increase in firing rates when a trial was not rewarded regardless of whether or not a reward was expected. We show that this signal is unrelated to error magnitude, reward prediction error, or other task confounds such as reward consumption, return reach plan, or kinematic differences across rewarded and unrewarded trials. The availability of reward information in motor cortex is crucial for theories of reward-based learning and motivational influences on actions.

  13. Balancing risk and reward: a rat model of risky decision making.

    Science.gov (United States)

    Simon, Nicholas W; Gilbert, Ryan J; Mayse, Jeffrey D; Bizon, Jennifer L; Setlow, Barry

    2009-09-01

    We developed a behavioral task in rats to assess the influence of risk of punishment on decision making. Male Long-Evans rats were given choices between pressing a lever to obtain a small, 'safe' food reward and a large food reward associated with risk of punishment (footshock). Each test session consisted of 5 blocks of 10 choice trials, with punishment risk increasing with each consecutive block (0, 25, 50, 75, 100%). Preference for the large, 'risky' reward declined with both increased probability and increased magnitude of punishment, and reward choice was not affected by the level of satiation or the order of risk presentation. Performance in this risky decision-making task was correlated with the degree to which the rats discounted the value of probabilistic rewards, but not delayed rewards. Finally, the acute effects of different doses of amphetamine and cocaine on risky decision making were assessed. Systemic amphetamine administration caused a dose-dependent decrease in choice of the large risky reward (ie, it made rats more risk averse). Cocaine did not cause a shift in reward choice, but instead impaired the rats' sensitivity to changes in punishment risk. These results should prove useful for investigating neuropsychiatric disorders in which risk taking is a prominent feature, such as attention deficit/hyperactivity disorder and addiction.

  14. Common and distinct neural correlates of personal and vicarious reward: A quantitative meta-analysis

    Science.gov (United States)

    Morelli, Sylvia A.; Sacchet, Matthew D.; Zaki, Jamil

    2015-01-01

    Individuals experience reward not only when directly receiving positive outcomes (e.g., food or money), but also when observing others receive such outcomes. This latter phenomenon, known as vicarious reward, is a perennial topic of interest among psychologists and economists. More recently, neuroscientists have begun exploring the neuroanatomy underlying vicarious reward. Here we present a quantitative whole-brain meta-analysis of this emerging literature. We identified 25 functional neuroimaging studies that included contrasts between vicarious reward and a neutral control, and subjected these contrasts to an activation likelihood estimate (ALE) meta-analysis. This analysis revealed a consistent pattern of activation across studies, spanning structures typically associated with the computation of value (especially ventromedial prefrontal cortex) and mentalizing (including dorsomedial prefrontal cortex and superior temporal sulcus). We further quantitatively compared this activation pattern to activation foci from a previous meta-analysis of personal reward. Conjunction analyses yielded overlapping VMPFC activity in response to personal and vicarious reward. Contrast analyses identified preferential engagement of the nucleus accumbens in response to personal as compared to vicarious reward, and in mentalizing-related structures in response to vicarious as compared to personal reward. These data shed light on the common and unique components of the reward that individuals experience directly and through their social connections. PMID:25554428

  15. Glutamatergic transmission in drug reward: implications for drug addiction.

    Science.gov (United States)

    D'Souza, Manoranjan S

    2015-01-01

    Individuals addicted to drugs of abuse such as alcohol, nicotine, cocaine, and heroin are a significant burden on healthcare systems all over the world. The positive reinforcing (rewarding) effects of the above mentioned drugs play a major role in the initiation and maintenance of the drug-taking habit. Thus, understanding the neurochemical mechanisms underlying the reinforcing effects of drugs of abuse is critical to reducing the burden of drug addiction in society. Over the last two decades, there has been an increasing focus on the role of the excitatory neurotransmitter glutamate in drug addiction. In this review, pharmacological and genetic evidence supporting the role of glutamate in mediating the rewarding effects of the above described drugs of abuse will be discussed. Further, the review will discuss the role of glutamate transmission in two complex heterogeneous brain regions, namely the nucleus accumbens (NAcc) and the ventral tegmental area (VTA), which mediate the rewarding effects of drugs of abuse. In addition, several medications approved by the Food and Drug Administration that act by blocking glutamate transmission will be discussed in the context of drug reward. Finally, this review will discuss future studies needed to address currently unanswered gaps in knowledge, which will further elucidate the role of glutamate in the rewarding effects of drugs of abuse.

  16. Glutamatergic transmission in drug reward: Implications for drug addiction

    Directory of Open Access Journals (Sweden)

    Manoranjan S Dsouza

    2015-11-01

    Full Text Available Individuals addicted to drugs of abuse such as alcohol, nicotine, cocaine, and heroin are a significant burden on healthcare systems all over the world. The positive reinforcing (rewarding effects of the above mentioned drugs play a major role in the initiation and maintenance of the drug-taking habit. Thus, understanding the neurochemical mechanisms underlying the reinforcing effects of drugs of abuse is critical to reducing the burden of drug addiction in society. Over the last two decades, there has been an increasing focus on the role of the excitatory neurotransmitter glutamate in drug addiction. In this review, pharmacological and genetic evidence supporting the role of glutamate in mediating the rewarding effects of the above described drugs of abuse will be discussed. Further, the review will discuss the role of glutamate transmission in two complex heterogeneous brain regions, namely the nucleus accumbens (NAcc and the ventral tegmental area (VTA, which mediate the rewarding effects of drugs of abuse. In addition, several medications approved by the Food and Drug Administration that act by blocking glutamate transmission will be discussed in the context of drug reward. Finally, this review will discuss future studies needed to address currently unanswered gaps in knowledge, which will further elucidate the role of glutamate in the rewarding effects of drugs of abuse.

  17. Hidden inventory and safety considerations

    International Nuclear Information System (INIS)

    Anderson, A.R.; James, R.H.; Morgan, F.

    1976-01-01

    Preliminary results are described of the evaluation of residual plutonium in a process line used for the production of experimental fast reactor fuel. Initial attention has been focussed on a selection of work boxes used for processing powders and solutions. Amounts of material measured as ''hidden inventory'' are generally less than 0.1 percent of throughput but in one box containing very complex equipment the amount was exceptionally about 0.5 percent. The total surface area of the box and the installed equipment appears to be the most significant factor in determining the amount of plutonium held-up as ''hidden inventory,'' representing an average of about 4 x 10 -4 g cm -2 . Present results are based on gamma spectrometer measurements but neutron techniques are being developed to overcome some of the inherent uncertainties in the gamma method. It is suggested that the routine use of sample plates of known surface area would be valuable in monitoring the deposition of plutonium in work boxes

  18. Hidden costs of nuclear power

    International Nuclear Information System (INIS)

    England, R.W.

    1979-01-01

    Mr. England contends that these hidden costs add up to a figure much higher than those that appear in the electric utilities' profit and loss account - costs that are borne by Federal taxpayers, by nuclear industry workers, and by all those people who must share their environment with nuclear facilities. Costs he details are additional deaths and illnesses resulting from exposure to radiation, and the use of tax dollars to clean up the lethal garbage produced by those activities. He asserts that careless handling of uranium ore and mill tailings in past years has apparently resulted in serious public health problems in those mining communities. In another example, Mr. England states that the failure to isolate uranium tailings physically from their environment has probably contributed to an acute leukemia rate in Mesa County, Colorado. He mentions much of the technology development for power reactors being done by the Federal government, not by private reactor manufacturers - thus, again, hidden costs that do not show up in electric bills of customers. The back end of the nuclear fuel cycle as a place for Federally subsidized research and development is discussed briefly. 1 figure, 2 tables

  19. The Hidden Reason Behind Children's Misbehavior.

    Science.gov (United States)

    Nystul, Michael S.

    1986-01-01

    Discusses hidden reason theory based on the assumptions that: (1) the nature of people is positive; (2) a child's most basic psychological need is involvement; and (3) a child has four possible choices in life (good somebody, good nobody, bad somebody, or severely mentally ill.) A three step approach for implementing hidden reason theory is…

  20. Hidden neural networks: application to speech recognition

    DEFF Research Database (Denmark)

    Riis, Søren Kamaric

    1998-01-01

    We evaluate the hidden neural network HMM/NN hybrid on two speech recognition benchmark tasks; (1) task independent isolated word recognition on the Phonebook database, and (2) recognition of broad phoneme classes in continuous speech from the TIMIT database. It is shown how hidden neural networks...

  1. Insight: Exploring Hidden Roles in Collaborative Play

    Directory of Open Access Journals (Sweden)

    Tricia Shi

    2015-06-01

    Full Text Available This paper looks into interaction modes between players in co-located, collaborative games. In particular, hidden traitor games, in which one or more players is secretly working against the group mission, has the effect of increasing paranoia and distrust between players, so this paper looks into the opposite of a hidden traitor – a hidden benefactor. Rather than sabotaging the group mission, the hidden benefactor would help the group achieve the end goal while still having a reason to stay hidden. The paper explores what games with such a role can look like and how the role changes player interactions. Finally, the paper addresses the divide between video game and board game interaction modes; hidden roles are not common within video games, but they are of growing prevalence in board games. This fact, combined with the exploration of hidden benefactors, reveals that hidden roles is a mechanic that video games should develop into in order to match board games’ complexity of player interaction modes.

  2. Hidden variables and locality in quantum theory

    International Nuclear Information System (INIS)

    Shiva, Vandana.

    1978-12-01

    The status of hidden variables in quantum theory has been debated since the 1920s. The author examines the no-hidden-variable theories of von Neumann, Kochen, Specker and Bell, and finds that they all share one basic assumption: averaging over the hidden variables should reproduce the quantum mechanical probabilities. Von Neumann also makes a linearity assumption, Kochen and Specker require the preservation of certain functional relations between magnitudes, and Bell proposes a locality condition. It has been assumed that the extrastatistical requirements are needed to serve as criteria of success for the introduction of hidden variables because the statistical condition is trivially satisfied, and that Bell's result is based on a locality condition that is physically motivated. The author shows that the requirement of weak locality, which is not physically motivated, is enough to give Bell's result. The proof of Bell's inequality works equally well for any pair of commuting magnitudes satisfying a condition called the degeneracy principle. None of the no-hidden-variable proofs apply to a class of hidden variable theories that are not phase-space reconstructions of quantum mechanics. The author discusses one of these theories, the Bohm-Bub theory, and finds that hidden variable theories that re all the quantum statistics, for single and sequential measurements, must introduce a randomization process for the hidden variables after each measurement. The philosophical significance of this theory lies in the role it can play in solving the conceptual puzzles posed by quantum theory

  3. Hidden supersymmetry and Fermion number fractionalization

    International Nuclear Information System (INIS)

    Akhoury, R.

    1985-01-01

    This paper discusses how a hidden supersymmetry of the underlying field theories can be used to interpret and to calculate fermion number fractionalization in different dimensions. This is made possible by relating it to a corresponding Witten index of the hidden supersymmetry. The closely related anomalies in odd dimensions are also discussed

  4. Neural Mechanisms of Circadian Regulation of Natural and Drug Reward

    Directory of Open Access Journals (Sweden)

    Lauren M. DePoy

    2017-01-01

    Full Text Available Circadian rhythms are endogenously generated near 24-hour variations of physiological and behavioral functions. In humans, disruptions to the circadian system are associated with negative health outcomes, including metabolic, immune, and psychiatric diseases, such as addiction. Animal models suggest bidirectional relationships between the circadian system and drugs of abuse, whereby desynchrony, misalignment, or disruption may promote vulnerability to drug use and the transition to addiction, while exposure to drugs of abuse may entrain, disrupt, or perturb the circadian timing system. Recent evidence suggests natural (i.e., food and drug rewards may influence overlapping neural circuitry, and the circadian system may modulate the physiological and behavioral responses to these stimuli. Environmental disruptions, such as shifting schedules or shorter/longer days, influence food and drug intake, and certain mutations of circadian genes that control cellular rhythms are associated with altered behavioral reward. We highlight the more recent findings associating circadian rhythms to reward function, linking environmental and genetic evidence to natural and drug reward and related neural circuitry.

  5. Enabling food security by verifying agricultural carbon

    DEFF Research Database (Denmark)

    Kahiluoto, H; Smith, P; Moran, D

    2014-01-01

    Rewarding smallholders for sequestering carbon in agricultural land can improve food security while mitigating climate change. Verification of carbon offsets in food-insecure regions is possible and achievable through rigorously controlled monitoring......Rewarding smallholders for sequestering carbon in agricultural land can improve food security while mitigating climate change. Verification of carbon offsets in food-insecure regions is possible and achievable through rigorously controlled monitoring...

  6. Helioscope bounds on hidden sector photons

    International Nuclear Information System (INIS)

    Redondo, J.

    2008-01-01

    The flux of hypothetical ''hidden photons'' from the Sun is computed under the assumption that they interact with normal matter only through kinetic mixing with the ordinary standard model photon. Requiring that the exotic luminosity is smaller than the standard photon luminosity provides limits for the mixing parameter down to χ -14 , depending on the hidden photon mass. Furthermore, it is pointed point out that helioscopes looking for solar axions are also sensitive to hidden photons. The recent results of the CAST collaboration are used to further constrain the mixing parameter χ at low masses (m γ' <1 eV) where the luminosity bound is weaker. In this regime the solar hidden photon ux has a sizable contribution of longitudinally polarized hidden photons of low energy which are invisible for current helioscopes. (orig.)

  7. Evolutionary advantages of adaptive rewarding

    International Nuclear Information System (INIS)

    Szolnoki, Attila; Perc, Matjaž

    2012-01-01

    Our well-being depends on both our personal success and the success of our society. The realization of this fact makes cooperation an essential trait. Experiments have shown that rewards can elevate our readiness to cooperate, but since giving a reward inevitably entails paying a cost for it, the emergence and stability of such behavior remains elusive. Here we show that allowing for the act of rewarding to self-organize in dependence on the success of cooperation creates several evolutionary advantages that instill new ways through which collaborative efforts are promoted. Ranging from indirect territorial battle to the spontaneous emergence and destruction of coexistence, phase diagrams and the underlying spatial patterns reveal fascinatingly rich social dynamics that explain why this costly behavior has evolved and persevered. Comparisons with adaptive punishment, however, uncover an Achilles heel of adaptive rewarding, coming from over-aggression, which in turn hinders optimal utilization of network reciprocity. This may explain why, despite its success, rewarding is not as firmly embedded into our societal organization as punishment. (paper)

  8. Measuring Preference for Supernormal Over Natural Rewards

    Directory of Open Access Journals (Sweden)

    B. C. Goodwin

    2015-10-01

    Full Text Available Supernormal (SN stimuli are artificial products that activate reward pathways and approach behavior more so than naturally occurring stimuli for which these systems were intended. Many modern consumer products (e.g., snack foods, alcohol, and pornography appear to incorporate SN features, leading to excessive consumption, in preference to naturally occurring alternatives. No measure currently exists for the self-report assessment of individual differences or changes in susceptibility to such stimuli. Therefore, an anticipatory pleasure scale was modified to include items that represented both SN and natural (N classes of rewarding stimuli. Exploratory factor analysis yielded a two-factor solution, and as predicted, N and SN items reliably loaded on separate dimensions. Internal reliability for the two scales was high, ρ =.93 and ρ =.90, respectively. The two-dimensional measure was evaluated via regression using the N and SN scale means as predictors and self-reports of daily consumption of 21 products with SN features as outcomes. As expected, SN pleasure ratings were related to higher SN product consumption, while N pleasure ratings had either negative or neutral associations to consumption of these products. We conclude that the resulting two-dimensional measure is a potentially reliable and valid self-report measure of differential preference for SN stimuli. While further evaluation is needed (e.g., using experimental measures, the proposed scale may play a useful role in the study of both trait- and state-based variation in human susceptibility to SN stimuli.

  9. Hidden scale invariance of metals

    DEFF Research Database (Denmark)

    Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.

    2015-01-01

    Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general “hidden” scale invariance...... of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were...... available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant...

  10. Hidden Valley Search at ATLAS

    CERN Document Server

    Verducci, M

    2011-01-01

    A number of extensions of the Standard Model result in neutral and weakly-coupled particles that decay to multi hadrons or multi leptons with macroscopic decay lengths. These particles with decay paths that can be comparable with ATLAS detector dimensions represent, from an experimental point of view, a challenge both for the trigger and for the reconstruction capabilities of the ATLAS detector. We will present a set of signature driven triggers for the ATLAS detector that target such displaced decays and evaluate their performances for some benchmark models and describe analysis strategies and limits on the production of such long-lived particles. A first estimation of the Hidden Valley trigger rates has been evaluated with 6 pb-1 of data collected at ATLAS during the data taking of 2010.

  11. The Social Rewards of Engagement

    DEFF Research Database (Denmark)

    Robison, Joshua

    2017-01-01

    Political interest is a crucial precursor to political engagement, but little is known about how to stimulate greater interest. The article explores the role social motives have in generating interest. A laboratory experiment is used in which it is possible to manipulate beliefs about the social...... rewards of political engagement as well as external efficacy beliefs. Across two types of measures for political interest (self-reports and revealed preferences), connecting political engagement with social rewards led to substantial increases in political interest. Moreover, these effects were...... particularly strong among individuals with low levels of external efficacy. Ultimately, the data provide clear evidence that political interest can be positively stimulated with social rewards mobilisation techniques and that it is rooted in beliefs about the potential motives pursuable through politics...

  12. Memory for multiple cache locations and prey quantities in a food-hoarding songbird

    Directory of Open Access Journals (Sweden)

    Nicola eArmstrong

    2012-12-01

    Full Text Available Most animals can discriminate between pairs of numbers that are each less than four without training. However, North Island robins (Petroica longipes, a food hoarding songbird endemic to New Zealand, can discriminate between quantities of items as high as eight without training. Here we investigate whether robins are capable of other complex quantity discrimination tasks. We test whether their ability to discriminate between small quantities declines with 1. the number of cache sites containing prey rewards and 2. the length of time separating cache creation and retrieval (retention interval. Results showed that subjects generally performed above chance expectations. They were equally able to discriminate between different combinations of prey quantities that were hidden from view in 2, 3 and 4 cache sites from between 1, 10 and 60 seconds. Overall results indicate that North Island robins can process complex quantity information involving more than two discrete quantities of items for up to one minute long retention intervals without training.

  13. Introduction: Addiction and Brain Reward and Anti-Reward Pathways

    Science.gov (United States)

    Gardner, Eliot L.

    2013-01-01

    Addictive drugs have in common that they are voluntarily self-administered by laboratory animals (usually avidly) and that they enhance the functioning of the reward circuitry of the brain (producing the “high” that the drug-user seeks). The core reward circuitry consists of an “in series” circuit linking the ventral tegmental area, nucleus accumbens, and ventral pallidum - via the medial forebrain bundle. Although originally believed to encode simply the set-point of hedonic tone, these circuits are now believed to be functionally far more complex - also encoding attention, expectancy of reward, disconfirmation of reward expectancy, and incentive motivation. “Hedonic dysregulation” within these circuits may lead to addiction. The “second-stage” dopaminergic component in this reward circuitry is the crucial addictive-drug-sensitive component. All addictive drugs have in common that they enhance (directly or indirectly or even transsynaptically) dopaminergic reward synaptic function in the nucleus accumbens. Drug self-administration is regulated by nucleus accumbens dopamine levels, and is done to keep nucleus accumbens dopamine within a specific elevated range (to maintain a desired hedonic level). For some classes of addictive drugs (e.g., opiates), tolerance to the euphoric effects develops with chronic use. Post-use dysphoria then comes to dominate reward circuit hedonic tone, and addicts no longer use drugs to get “high,” but simply to get back to normal (“get straight”). The brain circuits mediating the pleasurable effects of addictive drugs are anatomically, neurophysiologically, and neurochemically different from those mediating physical dependence, and from those mediating craving and relapse. There are important genetic variations in vulnerability to drug addiction, yet environmental factors such as stress and social defeat also alter brain-reward mechanisms in such a manner as to impart vulnerability to addiction. In short, the

  14. A survey of hidden-variables theories

    CERN Document Server

    Belinfante, F J

    1973-01-01

    A Survey of Hidden-Variables Theories is a three-part book on the hidden-variable theories, referred in this book as """"theories of the first kind"""". Part I reviews the motives in developing different types of hidden-variables theories. The quest for determinism led to theories of the first kind; the quest for theories that look like causal theories when applied to spatially separated systems that interacted in the past led to theories of the second kind. Parts II and III further describe the theories of the first kind and second kind, respectively. This book is written to make the literat

  15. A classification of hidden-variable properties

    International Nuclear Information System (INIS)

    Brandenburger, Adam; Yanofsky, Noson

    2008-01-01

    Hidden variables are extra components added to try to banish counterintuitive features of quantum mechanics. We start with a quantum-mechanical model and describe various properties that can be asked of a hidden-variable model. We present six such properties and a Venn diagram of how they are related. With two existence theorems and three no-go theorems (EPR, Bell and Kochen-Specker), we show which properties of empirically equivalent hidden-variable models are possible and which are not. Formally, our treatment relies only on classical probability models, and physical phenomena are used only to motivate which models to choose

  16. Adult neurogenesis affects motivation to obtain weak, but not strong, reward in operant tasks.

    Science.gov (United States)

    Karlsson, Rose-Marie; Wang, Alice S; Sonti, Anup N; Cameron, Heather A

    2018-04-16

    Decreased motivation to seek rewards is a key feature of mood disorders that correlates with severity and treatment outcome. This anhedonia, or apathy, likely reflects impairment in reward circuitry, but the specific neuronal populations controlling motivation are unclear. Granule neurons generated in the adult hippocampus have been implicated in mood disorders, but are not generally considered as part of reward circuits. We investigated a possible role of these new neurons in motivation to work for food and sucrose rewards in operant conditioning tasks using GFAP-TK pharmacogenetic ablation of adult neurogenesis in both rats and mice. Rats and mice lacking adult neurogenesis showed normal lever press responding during fixed ratio training, reward devaluation, and Pavlovian Instrumental Transfer, suggesting no impairment in learning. However, on an exponentially progressive ratio schedule, or when regular chow was freely available in the testing chamber, TK rats and mice showed less effort to gain sucrose tablets. When working for balanced food tablets, which rats and mice of both genotypes strongly preferred over sucrose, the genotype effects on behavior were lost. This decrease in effort under conditions of low reward suggests that loss of adult neurogenesis decreases motivation to seek reward in a manner that may model behavioral apathy. © 2018 Wiley Periodicals, Inc.

  17. A novel operant task to assess social reward and motivation in rodents.

    Science.gov (United States)

    Borland, Johnathan M; Frantz, Kyle J; Aiani, Lauren M; Grantham, Kymberly N; Song, Zhimin; Albers, H Elliott

    2017-08-01

    Social reward plays a critical role in the development of beneficial social relationships, and disorders of the mechanisms controlling social reward are involved in the etiology of many psychiatric diseases. We present a novel operant social preference task to quantify social reward in rodents using an apparatus with three chambers separated by one-way vertical-swing doors. The experimental animal is placed in the larger chamber while the two smaller chambers either remain empty or contain a stimulus animal or other potential reward stimulus. Adding weights to the door can alter effort required for rewards. Hamsters (Mesocricetus auratus) entered the chamber containing a stimulus hamster significantly more frequently than an empty chamber. When the reinforcing effects of social interactions were compared to food reward under progressive cost requirements, the reinforcing effects of social interaction and sunflower seeds were similar. Progressively increasing the door weight decreased number of entries, but increased time spent attempting to open the doors. The quantification of the rewarding properties of social interactions has almost exclusively used the conditioned place preference (CPP) paradigm. Although robust and reliable, CPP includes a memory component, because it relies on the association of place with the social interaction while the operant task presented here does not. This task allows for detailed and direct assessment of social and non-social rewards that may serve as effective behavioral reinforcers in this operant conditioning model, and it can be used to investigate the neural mechanisms regulating motivation. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Belief reward shaping in reinforcement learning

    CSIR Research Space (South Africa)

    Marom, O

    2018-02-01

    Full Text Available A key challenge in many reinforcement learning problems is delayed rewards, which can significantly slow down learning. Although reward shaping has previously been introduced to accelerate learning by bootstrapping an agent with additional...

  19. Addiction: beyond dopamine reward circuitry.

    Science.gov (United States)

    Volkow, Nora D; Wang, Gene-Jack; Fowler, Joanna S; Tomasi, Dardo; Telang, Frank

    2011-09-13

    Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction is much less clear. This review focuses on studies that used PET to characterize the brain DA system in addicted subjects. These studies have corroborated in humans the relevance of drug-induced fast DA increases in striatum [including nucleus accumbens (NAc)] in their rewarding effects but have unexpectedly shown that in addicted subjects, drug-induced DA increases (as well as their subjective reinforcing effects) are markedly blunted compared with controls. In contrast, addicted subjects show significant DA increases in striatum in response to drug-conditioned cues that are associated with self-reports of drug craving and appear to be of a greater magnitude than the DA responses to the drug. We postulate that the discrepancy between the expectation for the drug effects (conditioned responses) and the blunted pharmacological effects maintains drug taking in an attempt to achieve the expected reward. Also, whether tested during early or protracted withdrawal, addicted subjects show lower levels of D2 receptors in striatum (including NAc), which are associated with decreases in baseline activity in frontal brain regions implicated in salience attribution (orbitofrontal cortex) and inhibitory control (anterior cingulate gyrus), whose disruption results in compulsivity and impulsivity. These results point to an imbalance between dopaminergic circuits that underlie reward and conditioning and those that underlie executive function (emotional control and decision making), which we postulate contributes to the compulsive drug use and loss of control in addiction.

  20. Addiction: Beyond dopamine reward circuitry

    International Nuclear Information System (INIS)

    Volkow, N.D.; Wang, G.-J.; Fowler, J.S.; Tomasi, D.; Telang, F.

    2011-01-01

    Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction is much less clear. This review focuses on studies that used PET to characterize the brain DA system in addicted subjects. These studies have corroborated in humans the relevance of drug-induced fast DA increases in striatum [including nucleus accumbens (NAc)] in their rewarding effects but have unexpectedly shown that in addicted subjects, drug-induced DA increases (as well as their subjective reinforcing effects) are markedly blunted compared with controls. In contrast, addicted subjects show significant DA increases in striatum in response to drug-conditioned cues that are associated with self-reports of drug craving and appear to be of a greater magnitude than the DA responses to the drug. We postulate that the discrepancy between the expectation for the drug effects (conditioned responses) and the blunted pharmacological effects maintains drug taking in an attempt to achieve the expected reward. Also, whether tested during early or protracted withdrawal, addicted subjects show lower levels of D2 receptors in striatum (including NAc), which are associated with decreases in baseline activity in frontal brain regions implicated in salience attribution (orbitofrontal cortex) and inhibitory control (anterior cingulate gyrus), whose disruption results in compulsivity and impulsivity. These results point to an imbalance between dopaminergic circuits that underlie reward and conditioning and those that underlie executive function (emotional control and decision making), which we postulate contributes to the compulsive drug use and loss of control in addiction.

  1. Addiction: Beyond dopamine reward circuitry

    Energy Technology Data Exchange (ETDEWEB)

    Volkow, N.D.; Wang, G.; Volkow, N.D.; Wang, G.-J.; Fowler, J.S.; Tomasi, D.; Telang, F.

    2011-09-13

    Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction is much less clear. This review focuses on studies that used PET to characterize the brain DA system in addicted subjects. These studies have corroborated in humans the relevance of drug-induced fast DA increases in striatum [including nucleus accumbens (NAc)] in their rewarding effects but have unexpectedly shown that in addicted subjects, drug-induced DA increases (as well as their subjective reinforcing effects) are markedly blunted compared with controls. In contrast, addicted subjects show significant DA increases in striatum in response to drug-conditioned cues that are associated with self-reports of drug craving and appear to be of a greater magnitude than the DA responses to the drug. We postulate that the discrepancy between the expectation for the drug effects (conditioned responses) and the blunted pharmacological effects maintains drug taking in an attempt to achieve the expected reward. Also, whether tested during early or protracted withdrawal, addicted subjects show lower levels of D2 receptors in striatum (including NAc), which are associated with decreases in baseline activity in frontal brain regions implicated in salience attribution (orbitofrontal cortex) and inhibitory control (anterior cingulate gyrus), whose disruption results in compulsivity and impulsivity. These results point to an imbalance between dopaminergic circuits that underlie reward and conditioning and those that underlie executive function (emotional control and decision making), which we postulate contributes to the compulsive drug use and loss of control in addiction.

  2. Virtual Rewards for Driving Green

    Science.gov (United States)

    Pritchard, Josh

    2010-01-01

    Carbon dioxide from automobiles is a major contributor to global climate change. In "Virtual Rewards for Driving Green," Josh Pritchard proposes a computer application that will enable fuel-efficient drivers to earn "green" dollars with which to buy digital merchandise on the Web. Can getting items that exist only in cyberspace actually change a…

  3. Video game training and the reward system

    OpenAIRE

    Lorenz, R.; Gleich, T.; Gallinat, J.; Kühn, S.

    2015-01-01

    Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual toward playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors ...

  4. BOLD responses in reward regions to hypothetical and imaginary monetary rewards.

    Science.gov (United States)

    Miyapuram, Krishna P; Tobler, Philippe N; Gregorios-Pippas, Lucy; Schultz, Wolfram

    2012-01-16

    Monetary rewards are uniquely human. Because money is easy to quantify and present visually, it is the reward of choice for most fMRI studies, even though it cannot be handed over to participants inside the scanner. A typical fMRI study requires hundreds of trials and thus small amounts of monetary rewards per trial (e.g. 5p) if all trials are to be treated equally. However, small payoffs can have detrimental effects on performance due to their limited buying power. Hypothetical monetary rewards can overcome the limitations of smaller monetary rewards but it is less well known whether predictors of hypothetical rewards activate reward regions. In two experiments, visual stimuli were associated with hypothetical monetary rewards. In Experiment 1, we used stimuli predicting either visually presented or imagined hypothetical monetary rewards, together with non-rewarding control pictures. Activations to reward predictive stimuli occurred in reward regions, namely the medial orbitofrontal cortex and midbrain. In Experiment 2, we parametrically varied the amount of visually presented hypothetical monetary reward keeping constant the amount of actually received reward. Graded activation in midbrain was observed to stimuli predicting increasing hypothetical rewards. The results demonstrate the efficacy of using hypothetical monetary rewards in fMRI studies. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. A correction term for the covariance of renewal-reward processes with multivariate rewards

    NARCIS (Netherlands)

    Patch, B.; Nazarathy, Y.; Taimre, T.

    We consider a renewal-reward process with multivariate rewards. Such a process is constructed from an i.i.d. sequence of time periods, to each of which there is associated a multivariate reward vector. The rewards in each time period may depend on each other and on the period length, but not on the

  6. Hidden Benefits of Reward : A Field Experiment on Motivation and Monetary Incentives

    OpenAIRE

    Kvaløy, Ola; Nieken, Petra; Schöttner, Anja

    2013-01-01

    We conducted a field experiment in a controlled work environment to investigate the effect of motivational talk and its interaction with monetary incentives. We find that motivational talk significantly improves performance only when accompanied by performance pay. Moreover, performance pay slightly reduces performance unless it is accompanied by motivational talk. These effects also carry over to the quality of work. Performance pay alone leads to more mistakes. Adding motivational talk make...

  7. Discrete-time rewards model-checked

    NARCIS (Netherlands)

    Larsen, K.G.; Andova, S.; Niebert, Peter; Hermanns, H.; Katoen, Joost P.

    2003-01-01

    This paper presents a model-checking approach for analyzing discrete-time Markov reward models. For this purpose, the temporal logic probabilistic CTL is extended with reward constraints. This allows to formulate complex measures – involving expected as well as accumulated rewards – in a precise and

  8. Renewal processes with costs and rewards

    NARCIS (Netherlands)

    Vlasiou, M.; Cochran, J.J.; Cox, L.A.; Keskinocak, P.; Kharoufeh, J.P.; Smith, J.C.

    2011-01-01

    We review the theory of renewal reward processes, which describes renewal processes that have some cost or reward associated with each cycle. We present a new simplified proof of the renewal reward theorem that mimics the proof of the Elementary Renewal Theorem and avoids the technicalities in the

  9. Reward, Distraction, and the Overjustification Effect

    Science.gov (United States)

    Smith, Timothy W.; Pittman, Thane S.

    1978-01-01

    This study tests two differing hypotheses: the competing response hypothesis, which states that both reward and non-reward distractions produce decreases in interest which weaken over repeated trials, and the attribution/overjustification hypothesis, which maintains that rewards produce a decrease in interest that does not weaken over trials.…

  10. A Fly’s Eye View of Natural and Drug Reward

    Directory of Open Access Journals (Sweden)

    Eve G. Lowenstein

    2018-04-01

    Full Text Available Animals encounter multiple stimuli each day. Some of these stimuli are innately appetitive or aversive, while others are assigned valence based on experience. Drugs like ethanol can elicit aversion in the short term and attraction in the long term. The reward system encodes the predictive value for different stimuli, mediating anticipation for attractive or punishing stimuli and driving animal behavior to approach or avoid conditioned stimuli. The neurochemistry and neurocircuitry of the reward system is partly evolutionarily conserved. In both vertebrates and invertebrates, including Drosophila melanogaster, dopamine is at the center of a network of neurotransmitters and neuromodulators acting in concert to encode rewards. Behavioral assays in D. melanogaster have become increasingly sophisticated, allowing more direct comparison with mammalian research. Moreover, recent evidence has established the functional modularity of the reward neural circuits in Drosophila. This functional modularity resembles the organization of reward circuits in mammals. The powerful genetic and molecular tools for D. melanogaster allow characterization and manipulation at the single-cell level. These tools are being used to construct a detailed map of the neural circuits mediating specific rewarding stimuli and have allowed for the identification of multiple genes and molecular pathways that mediate the effects of reinforcing stimuli, including their rewarding effects. This report provides an overview of the research on natural and drug reward in D. melanogaster, including natural rewards such as sugar and other food nutrients, and drug rewards including ethanol, cocaine, amphetamine, methamphetamine, and nicotine. We focused mainly on the known genetic and neural mechanisms underlying appetitive reward for sugar and reward for ethanol. We also include genes, molecular pathways, and neural circuits that have been identified using assays that test the palatability of

  11. UV Photography Shows Hidden Sun Damage

    Science.gov (United States)

    ... mcat1=de12", ]; for (var c = 0; c UV photography shows hidden sun damage A UV photograph gives ... developing skin cancer and prematurely aged skin. Normal photography UV photography 18 months of age: This boy's ...

  12. Coding with partially hidden Markov models

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Rissanen, J.

    1995-01-01

    Partially hidden Markov models (PHMM) are introduced. They are a variation of the hidden Markov models (HMM) combining the power of explicit conditioning on past observations and the power of using hidden states. (P)HMM may be combined with arithmetic coding for lossless data compression. A general...... 2-part coding scheme for given model order but unknown parameters based on PHMM is presented. A forward-backward reestimation of parameters with a redefined backward variable is given for these models and used for estimating the unknown parameters. Proof of convergence of this reestimation is given....... The PHMM structure and the conditions of the convergence proof allows for application of the PHMM to image coding. Relations between the PHMM and hidden Markov models (HMM) are treated. Results of coding bi-level images with the PHMM coding scheme is given. The results indicate that the PHMM can adapt...

  13. Hidden costs, value lost: uninsurance in America

    National Research Council Canada - National Science Library

    Committee on the Consequences of Uninsurance

    2003-01-01

    Hidden Cost, Value Lost , the fifth of a series of six books on the consequences of uninsurance in the United States, illustrates some of the economic and social losses to the country of maintaining...

  14. The hidden epidemic: confronting sexually transmitted diseases

    National Research Council Canada - National Science Library

    Eng, Thomas R; Butler, William T

    .... In addition, STDs increase the risk of HIV transmission. The Hidden Epidemic examines the scope of sexually transmitted infections in the United States and provides a critical assessment of the nation's response to this public health crisis...

  15. Perspective: Disclosing hidden sources of funding.

    Science.gov (United States)

    Resnik, David B

    2009-09-01

    In this article, the author discusses ethical and policy issues related to the disclosure of hidden sources of funding in research. The author argues that authors have an ethical obligation to disclose hidden sources of funding and that journals should adopt policies to enforce this obligation. Journal policies should require disclosure of hidden sources of funding that authors know about and that have a direct relation to their research. To stimulate this discussion, the author describes a recent case: investigators who conducted a lung cancer screening study had received funding from a private foundation that was supported by a tobacco company, but they did not disclose this relationship to the journal. Investigators and journal editors must be prepared to deal with these issues in a manner that promotes honesty, transparency, fairness, and accountability in research. The development of well-defined, reasonable policies pertaining to hidden sources of funding can be a step in this direction.

  16. Petro Rents, Political Institutions, and Hidden Wealth

    DEFF Research Database (Denmark)

    Andersen, Jørgen Juel; Johannesen, Niels; Lassen, David Dreyer

    2017-01-01

    Do political institutions limit rent seeking by politicians? We study the transformation of petroleum rents, almost universally under direct government control, into hidden wealth using unique data on bank deposits in offshore financial centers that specialize in secrecy and asset protection. Our...... rulers is diverted to secret accounts. We find very limited evidence that shocks to other types of income not directly controlled by governments affect hidden wealth....

  17. Hidden charm molecules in a finite volume

    International Nuclear Information System (INIS)

    Albaladejo, M.; Hidalgo-Duque, C.; Nieves, J.; Oset, E.

    2014-01-01

    In the present paper we address the interaction of charmed mesons in hidden charm channels in a finite box. We use the interaction from a recent model based on heavy quark spin symmetry that predicts molecules of hidden charm in the infinite volume. The energy levels in the box are generated within this model, and several methods for the analysis of these levels ("inverse problem") are investigated. (author)

  18. Workplace ageism: discovering hidden bias.

    Science.gov (United States)

    Malinen, Sanna; Johnston, Lucy

    2013-01-01

    BACKGROUND/STUDY CONTEXT: Research largely shows no performance differences between older and younger employees, or that older workers even outperform younger employees, yet negative attitudes towards older workers can underpin discrimination. Unfortunately, traditional "explicit" techniques for assessing attitudes (i.e., self-report measures) have serious drawbacks. Therefore, using an approach that is novel to organizational contexts, the authors supplemented explicit with implicit (indirect) measures of attitudes towards older workers, and examined the malleability of both. This research consists of two studies. The authors measured self-report (explicit) attitudes towards older and younger workers with a survey, and implicit attitudes with a reaction-time-based measure of implicit associations. In addition, to test whether attitudes were malleable, the authors measured attitudes before and after a mental imagery intervention, where the authors asked participants in the experimental group to imagine respected and valued older workers from their surroundings. Negative, stable implicit attitudes towards older workers emerged in two studies. Conversely, explicit attitudes showed no age bias and were more susceptible to change intervention, such that attitudes became more positive towards older workers following the experimental manipulation. This research demonstrates the unconscious nature of bias against older workers, and highlights the utility of implicit attitude measures in the context of the workplace. In the current era of aging workforce and skill shortages, implicit measures may be necessary to illuminate hidden workplace ageism.

  19. Hidden slow pulsars in binaries

    Science.gov (United States)

    Tavani, Marco; Brookshaw, Leigh

    1993-01-01

    The recent discovery of the binary containing the slow pulsar PSR 1718-19 orbiting around a low-mass companion star adds new light on the characteristics of binary pulsars. The properties of the radio eclipses of PSR 1718-19 are the most striking observational characteristics of this system. The surface of the companion star produces a mass outflow which leaves only a small 'window' in orbital phase for the detection of PSR 1718-19 around 400 MHz. At this observing frequency, PSR 1718-19 is clearly observable only for about 1 hr out of the total 6.2 hr orbital period. The aim of this Letter is twofold: (1) to model the hydrodynamical behavior of the eclipsing material from the companion star of PSR 1718-19 and (2) to argue that a population of binary slow pulsars might have escaped detection in pulsar surveys carried out at 400 MHz. The possible existence of a population of partially or totally hidden slow pulsars in binaries will have a strong impact on current theories of binary evolution of neutron stars.

  20. Reward value determines memory consolidation in parasitic wasps.

    Science.gov (United States)

    Kruidhof, H Marjolein; Pashalidou, Foteini G; Fatouros, Nina E; Figueroa, Ilich A; Vet, Louise E M; Smid, Hans M; Huigens, Martinus E

    2012-01-01

    Animals can store learned information in their brains through a series of distinct memory forms. Short-lasting memory forms can be followed by longer-lasting, consolidated memory forms. However, the factors determining variation in memory consolidation encountered in nature have thus far not been fully elucidated. Here, we show that two parasitic wasp species belonging to different families, Cotesia glomerata (Hymenoptera: Braconidae) and Trichogramma evanescens (Hymenoptera; Trichogrammatidae), similarly adjust the memory form they consolidate to a fitness-determining reward: egg-laying into a host-insect that serves as food for their offspring. Protein synthesis-dependent long-term memory (LTM) was consolidated after single-trial conditioning with a high-value host. However, single-trial conditioning with a low-value host induced consolidation of a shorter-lasting memory form. For Cotesia glomerata, we subsequently identified this shorter-lasting memory form as anesthesia-resistant memory (ARM) because it was not sensitive to protein synthesis inhibitors or anesthesia. Associative conditioning using a single reward of different value thus induced a physiologically different mechanism of memory formation in this species. We conclude that the memory form that is consolidated does not only change in response to relatively large differences in conditioning, such as the number and type of conditioning trials, but is also sensitive to more subtle differences, such as reward value. Reward-dependent consolidation of exclusive ARM or LTM provides excellent opportunities for within-species comparison of mechanisms underlying memory consolidation.

  1. Dopamine and reward: the anhedonia hypothesis 30 years on.

    Science.gov (United States)

    Wise, Roy A

    2008-10-01

    The anhedonia hypothesis--that brain dopamine plays a critical role in the subjective pleasure associated with positive rewards--was intended to draw the attention of psychiatrists to the growing evidence that dopamine plays a critical role in the objective reinforcement and incentive motivation associated with food and water, brain stimulation reward, and psychomotor stimulant and opiate reward. The hypothesis called to attention the apparent paradox that neuroleptics, drugs used to treat a condition involving anhedonia (schizophrenia), attenuated in laboratory animals the positive reinforcement that we normally associate with pleasure. The hypothesis held only brief interest for psychiatrists, who pointed out that the animal studies reflected acute actions of neuroleptics whereas the treatment of schizophrenia appears to result from neuroadaptations to chronic neuroleptic administration, and that it is the positive symptoms of schizophrenia that neuroleptics alleviate, rather than the negative symptoms that include anhedonia. Perhaps for these reasons, the hypothesis has had minimal impact in the psychiatric literature. Despite its limited heuristic value for the understanding of schizophrenia, however, the anhedonia hypothesis has had major impact on biological theories of reinforcement, motivation, and addiction. Brain dopamine plays a very important role in reinforcement of response habits, conditioned preferences, and synaptic plasticity in cellular models of learning and memory. The notion that dopamine plays a dominant role in reinforcement is fundamental to the psychomotor stimulant theory of addiction, to most neuroadaptation theories of addiction, and to current theories of conditioned reinforcement and reward prediction. Properly understood, it is also fundamental to recent theories of incentive motivation.

  2. Hidden Costs of Hospital Based Delivery from Two Tertiary Hospitals in Western Nepal.

    Science.gov (United States)

    Acharya, Jeevan; Kaehler, Nils; Marahatta, Sujan Babu; Mishra, Shiva Raj; Subedi, Sudarshan; Adhikari, Bipin

    2016-01-01

    Hospital based delivery has been an expensive experience for poor households because of hidden costs which are usually unaccounted in hospital costs. The main aim of this study was to estimate the hidden costs of hospital based delivery and determine the factors associated with the hidden costs. A hospital based cross-sectional study was conducted among 384 post-partum mothers with their husbands/house heads during the discharge time in Manipal Teaching Hospital and Western Regional Hospital, Pokhara, Nepal. A face to face interview with each respondent was conducted using a structured questionnaire. Hidden costs were calculated based on the price rate of the market during the time of the study. The total hidden costs for normal delivery and C-section delivery were 243.4 USD (US Dollar) and 321.6 USD respectively. Of the total maternity care expenditures; higher mean expenditures were found for food & drinking (53.07%), clothes (9.8%) and transport (7.3%). For postpartum women with their husband or house head, the total mean opportunity cost of "days of work loss" were 84.1 USD and 81.9 USD for normal delivery and C-section respectively. Factors such as literate mother (p = 0.007), employed house head (p = 0.011), monthly family income more than 25,000 NRs (Nepalese Rupees) (p = 0.014), private hospital as a place of delivery (p = 0.0001), C-section as a mode of delivery (p = 0.0001), longer duration (>5days) of stay in hospital (p = 0.0001), longer distance (>15km) from house to hospital (p = 0.0001) and longer travel time (>240 minutes) from house to hospital (p = 0.007) showed a significant association with the higher hidden costs (>25000 NRs). Experiences of hidden costs on hospital based delivery and opportunity costs of days of work loss were found high. Several socio-demographic factors, delivery related factors (place and mode of delivery, length of stay, distance from hospital and travel time) were associated with hidden costs. Hidden costs can be a

  3. Hidden Costs of Hospital Based Delivery from Two Tertiary Hospitals in Western Nepal.

    Directory of Open Access Journals (Sweden)

    Jeevan Acharya

    Full Text Available Hospital based delivery has been an expensive experience for poor households because of hidden costs which are usually unaccounted in hospital costs. The main aim of this study was to estimate the hidden costs of hospital based delivery and determine the factors associated with the hidden costs.A hospital based cross-sectional study was conducted among 384 post-partum mothers with their husbands/house heads during the discharge time in Manipal Teaching Hospital and Western Regional Hospital, Pokhara, Nepal. A face to face interview with each respondent was conducted using a structured questionnaire. Hidden costs were calculated based on the price rate of the market during the time of the study.The total hidden costs for normal delivery and C-section delivery were 243.4 USD (US Dollar and 321.6 USD respectively. Of the total maternity care expenditures; higher mean expenditures were found for food & drinking (53.07%, clothes (9.8% and transport (7.3%. For postpartum women with their husband or house head, the total mean opportunity cost of "days of work loss" were 84.1 USD and 81.9 USD for normal delivery and C-section respectively. Factors such as literate mother (p = 0.007, employed house head (p = 0.011, monthly family income more than 25,000 NRs (Nepalese Rupees (p = 0.014, private hospital as a place of delivery (p = 0.0001, C-section as a mode of delivery (p = 0.0001, longer duration (>5days of stay in hospital (p = 0.0001, longer distance (>15km from house to hospital (p = 0.0001 and longer travel time (>240 minutes from house to hospital (p = 0.007 showed a significant association with the higher hidden costs (>25000 NRs.Experiences of hidden costs on hospital based delivery and opportunity costs of days of work loss were found high. Several socio-demographic factors, delivery related factors (place and mode of delivery, length of stay, distance from hospital and travel time were associated with hidden costs. Hidden costs can be a

  4. Incremental effects of reward on creativity.

    Science.gov (United States)

    Eisenberger, R; Rhoades, L

    2001-10-01

    The authors examined 2 ways reward might increase creativity. First, reward contingent on creativity might increase extrinsic motivation. Studies 1 and 2 found that repeatedly giving preadolescent students reward for creative performance in 1 task increased their creativity in subsequent tasks. Study 3 reported that reward promised for creativity increased college students' creative task performance. Second, expected reward for high performance might increase creativity by enhancing perceived self-determination and, therefore, intrinsic task interest. Study 4 found that employees' intrinsic job interest mediated a positive relationship between expected reward for high performance and creative suggestions offered at work. Study 5 found that employees' perceived self-determination mediated a positive relationship between expected reward for high performance and the creativity of anonymous suggestions for helping the organization.

  5. Brain Circuits Encoding Reward from Pain Relief.

    Science.gov (United States)

    Navratilova, Edita; Atcherley, Christopher W; Porreca, Frank

    2015-11-01

    Relief from pain in humans is rewarding and pleasurable. Primary rewards, or reward-predictive cues, are encoded in brain reward/motivational circuits. While considerable advances have been made in our understanding of reward circuits underlying positive reinforcement, less is known about the circuits underlying the hedonic and reinforcing actions of pain relief. We review findings from electrophysiological, neuroimaging, and behavioral studies supporting the concept that the rewarding effect of pain relief requires opioid signaling in the anterior cingulate cortex (ACC), activation of midbrain dopamine neurons, and the release of dopamine in the nucleus accumbens (NAc). Understanding of circuits that govern the reward of pain relief may allow the discovery of more effective and satisfying therapies for patients with acute or chronic pain.

  6. Ventral pallidum roles in reward and motivation.

    Science.gov (United States)

    Smith, Kyle S; Tindell, Amy J; Aldridge, J Wayne; Berridge, Kent C

    2009-01-23

    In recent years the ventral pallidum has become a focus of great research interest as a mechanism of reward and incentive motivation. As a major output for limbic signals, the ventral pallidum was once associated primarily with motor functions rather than regarded as a reward structure in its own right. However, ample evidence now suggests that ventral pallidum function is a major mechanism of reward in the brain. We review data indicating that (1) an intact ventral pallidum is necessary for normal reward and motivation, (2) stimulated activation of ventral pallidum is sufficient to cause reward and motivation enhancements, and (3) activation patterns in ventral pallidum neurons specifically encode reward and motivation signals via phasic bursts of excitation to incentive and hedonic stimuli. We conclude that the ventral pallidum may serve as an important 'limbic final common pathway' for mesocorticolimbic processing of many rewards.

  7. Learned reward association improves visual working memory.

    Science.gov (United States)

    Gong, Mengyuan; Li, Sheng

    2014-04-01

    Statistical regularities in the natural environment play a central role in adaptive behavior. Among other regularities, reward association is potentially the most prominent factor that influences our daily life. Recent studies have suggested that pre-established reward association yields strong influence on the spatial allocation of attention. Here we show that reward association can also improve visual working memory (VWM) performance when the reward-associated feature is task-irrelevant. We established the reward association during a visual search training session, and investigated the representation of reward-associated features in VWM by the application of a change detection task before and after the training. The results showed that the improvement in VWM was significantly greater for items in the color associated with high reward than for those in low reward-associated or nonrewarded colors. In particular, the results from control experiments demonstrate that the observed reward effect in VWM could not be sufficiently accounted for by attentional capture toward the high reward-associated item. This was further confirmed when the effect of attentional capture was minimized by presenting the items in the sample and test displays of the change detection task with the same color. The results showed significantly larger improvement in VWM performance when the items in a display were in the high reward-associated color than those in the low reward-associated or nonrewarded colors. Our findings suggest that, apart from inducing space-based attentional capture, the learned reward association could also facilitate the perceptual representation of high reward-associated items through feature-based attentional modulation.

  8. Obesity is associated with high serotonin 4 receptor availability in the brain reward circuitry

    DEFF Research Database (Denmark)

    Haahr, M. E.; Rasmussen, Peter Mondrup; Madsen, K.

    2012-01-01

    in food intake, and that pharmacological or genetic manipulation of the receptor in reward-related brain areas alters food intake.Here, we used positron emission tomography in humans to examine the association between cerebral 5-HT4Rs and common obesity.We found in humans a strong positive association......The neurobiology underlying obesity is not fully understood. The neurotransmitter serotonin (5-HT) is established as a satiety-generating signal, but its rewarding role in feeding is less well elucidated. From animal experiments there is now evidence that the 5-HT4 receptor (5-HT4R) is involved......'s food intake. They also suggest that pharmacological stimulation of the cerebral 5-HT4R may reduce reward-related overeating in humans....

  9. Reward and Punishment in Minigames

    OpenAIRE

    Sigmund, K.; Hauert, C.; Nowak, M.A.

    2001-01-01

    Minigames capturing the essence of Public Goods experiments show that even in the absence of rationality assumptions, both punishment and reward will fail to bring about prosocial behavior. This result holds in particular for the well-known Ultimatum Game, which emerges as a special case. But reputation can induce fairness and cooperation in populations adapting through learning or imitation. Indeed, the inclusion of reputation effects in the corresponding dynamical models leads to the evolut...

  10. On the motivational properties of reward cues: Individual differences.

    Science.gov (United States)

    Robinson, Terry E; Yager, Lindsay M; Cogan, Elizabeth S; Saunders, Benjamin T

    2014-01-01

    Cues associated with rewards, such as food or drugs of abuse, can themselves acquire motivational properties. Acting as incentive stimuli, such cues can exert powerful control over motivated behavior, and in the case of cues associated with drugs, they can goad continued drug-seeking behavior and relapse. However, recent studies reviewed here suggest that there are large individual differences in the extent to which food and drug cues are attributed with incentive salience. Rats prone to approach reward cues (sign-trackers) attribute greater motivational value to discrete localizable cues and interoceptive cues than do rats less prone to approach reward cues (goal-trackers). In contrast, contextual cues appear to exert greater control over motivated behavior in goal-trackers than sign-trackers. It is possible to predict, therefore, before any experience with drugs, in which animals specific classes of drug cues will most likely reinstate drug-seeking behavior. The finding that different individuals may be sensitive to different triggers capable of motivating behavior and producing relapse suggests there may be different pathways to addiction, and has implications for thinking about individualized treatment. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Probing hidden sector photons through the Higgs window

    International Nuclear Information System (INIS)

    Ahlers, M.

    2008-07-01

    We investigate the possibility that a (light) hidden sector extra photon receives its mass via spontaneous symmetry breaking of a hidden sector Higgs boson, the so-called hidden-Higgs. The hidden-photon can mix with the ordinary photon via a gauge kinetic mixing term. The hidden-Higgs can couple to the Standard Model Higgs via a renormalizable quartic term - sometimes called the Higgs Portal. We discuss the implications of this light hidden-Higgs in the context of laser polarization and light-shining-through-the-wall experiments as well as cosmological, astrophysical, and non-Newtonian force measurements. For hidden-photons receiving their mass from a hidden-Higgs we find in the small mass regime significantly stronger bounds than the bounds on massive hidden sector photons alone. (orig.)

  12. Probing hidden sector photons through the Higgs window

    International Nuclear Information System (INIS)

    Ahlers, Markus; Jaeckel, Joerg; Redondo, Javier; Ringwald, Andreas

    2008-01-01

    We investigate the possibility that a (light) hidden sector extra photon receives its mass via spontaneous symmetry breaking of a hidden sector Higgs boson, the so-called hidden-Higgs. The hidden-photon can mix with the ordinary photon via a gauge kinetic mixing term. The hidden-Higgs can couple to the standard model Higgs via a renormalizable quartic term - sometimes called the Higgs portal. We discuss the implications of this light hidden-Higgs in the context of laser polarization and light-shining-through-the-wall experiments as well as cosmological, astrophysical, and non-Newtonian force measurements. For hidden-photons receiving their mass from a hidden-Higgs, we find in the small mass regime significantly stronger bounds than the bounds on massive hidden sector photons alone.

  13. Reward sensitivity is associated with brain activity during erotic stimulus processing.

    Science.gov (United States)

    Costumero, Victor; Barrós-Loscertales, Alfonso; Bustamante, Juan Carlos; Ventura-Campos, Noelia; Fuentes, Paola; Rosell-Negre, Patricia; Ávila, César

    2013-01-01

    The behavioral approach system (BAS) from Gray's reinforcement sensitivity theory is a neurobehavioral system involved in the processing of rewarding stimuli that has been related to dopaminergic brain areas. Gray's theory hypothesizes that the functioning of reward brain areas is modulated by BAS-related traits. To test this hypothesis, we performed an fMRI study where participants viewed erotic and neutral pictures, and cues that predicted their appearance. Forty-five heterosexual men completed the Sensitivity to Reward scale (from the Sensitivity to Punishment and Sensitivity to Reward Questionnaire) to measure BAS-related traits. Results showed that Sensitivity to Reward scores correlated positively with brain activity during reactivity to erotic pictures in the left orbitofrontal cortex, left insula, and right ventral striatum. These results demonstrated a relationship between the BAS and reward sensitivity during the processing of erotic stimuli, filling the gap of previous reports that identified the dopaminergic system as a neural substrate for the BAS during the processing of other rewarding stimuli such as money and food.

  14. Associations Between Neural Reward Processing and Binge Eating Among Adolescent Girls.

    Science.gov (United States)

    Bodell, Lindsay P; Wildes, Jennifer E; Goldschmidt, Andrea B; Lepage, Rachel; Keenan, Kate E; Guyer, Amanda E; Hipwell, Alison E; Stepp, Stephanie D; Forbes, Erika E

    2018-01-01

    Neuroimaging studies suggest that altered brain responses to food-related cues in reward-sensitive regions characterize individuals who experience binge-eating episodes. However, the absence of longitudinal data limits the understanding of whether reward-system alterations increase vulnerability to binge eating, as theorized in models of the development of this behavior. Adolescent girls (N = 122) completed a functional magnetic resonance imaging monetary reward task at age 16 years as part of an ongoing longitudinal study. Self-report of binge eating was assessed using the Eating Attitudes Test at ages 16 and 18 years. Regression analyses examined concurrent and longitudinal associations between the blood-oxygenation-level-dependent response to anticipating and winning monetary rewards and the severity of binge eating while controlling for age 16 depressive symptoms and socioeconomic status. Greater ventromedial prefrontal cortex and caudate responses to winning money were correlated with greater severity of binge eating concurrently but not prospectively. This study is the first to examine longitudinal associations between reward responding and binge eating in community-based, mostly low-socioeconomic status adolescent girls. Ventromedial prefrontal cortex response to reward outcome-possibly reflecting an enhanced subjective reward value-appears to be a state marker of binge-eating severity rather than a predictor of future severity. Copyright © 2017 The Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  15. Brain reward region responsivity of adolescents with and without parental substance use disorders.

    Science.gov (United States)

    Stice, Eric; Yokum, Sonja

    2014-09-01

    The present study tested the competing hypotheses that adolescents at risk for future substance abuse and dependence by virtue of parental substance use disorders show either weaker or stronger responsivity of brain regions implicated in reward relative to youth without parental history of substance use disorders. Adolescents (n = 52) matched on demographics with and without parental substance use disorders, as determined by diagnostic interviews, who denied substance use in the past year were compared on functional MRI (fMRI) paradigms assessing neural response to receipt and anticipated receipt of monetary and food reward. Parental-history-positive versus -negative adolescents showed greater activation in the left dorsolateral prefrontal cortex and bilateral putamen, and less activation in the fusiform gyrus and inferior temporal gyrus in response to anticipating winning money, as well as greater activation in the left midbrain and right paracentral lobule, and less activation in the right middle frontal gyrus in response to milkshake receipt. Results indicate that adolescents at risk for future onset of substance use disorders show elevated responsivity of brain regions implicated in reward, extending results from 2 smaller prior studies that found that individuals with versus without parental alcohol use disorders showed greater reward region response to anticipated monetary reward and pictures of alcohol. Collectively, results provide support for the reward surfeit model of substance use disorders, rather than the reward deficit model.

  16. Different populations of subthalamic neurons encode cocaine vs. sucrose reward and predict future error.

    Science.gov (United States)

    Lardeux, Sylvie; Paleressompoulle, Dany; Pernaud, Remy; Cador, Martine; Baunez, Christelle

    2013-10-01

    The search for treatment of cocaine addiction raises the challenge to find a way to diminish motivation for the drug without decreasing it for natural rewards. Subthalamic nucleus (STN) inactivation decreases motivation for cocaine while increasing motivation for food, suggesting that STN can dissociate different rewards. Here, we investigated how rat STN neurons respond to cues predicting cocaine or sucrose and to reward delivery while rats are performing a discriminative stimuli task. We show that different neuronal populations of STN neurons encode cocaine and sucrose. In addition, we show that STN activity at the cue onset predicts future error. When changing the reward predicted unexpectedly, STN neurons show capacities of adaptation, suggesting a role in reward-prediction error. Furthermore, some STN neurons show a response to executive error (i.e., "oops neurons") that is specific to the missed reward. These results position the STN as a nexus where natural rewards and drugs of abuse are coded differentially and can influence the performance. Therefore, STN can be viewed as a structure where action could be taken for the treatment of cocaine addiction.

  17. Reward sensitivity is associated with brain activity during erotic stimulus processing.

    Directory of Open Access Journals (Sweden)

    Victor Costumero

    Full Text Available The behavioral approach system (BAS from Gray's reinforcement sensitivity theory is a neurobehavioral system involved in the processing of rewarding stimuli that has been related to dopaminergic brain areas. Gray's theory hypothesizes that the functioning of reward brain areas is modulated by BAS-related traits. To test this hypothesis, we performed an fMRI study where participants viewed erotic and neutral pictures, and cues that predicted their appearance. Forty-five heterosexual men completed the Sensitivity to Reward scale (from the Sensitivity to Punishment and Sensitivity to Reward Questionnaire to measure BAS-related traits. Results showed that Sensitivity to Reward scores correlated positively with brain activity during reactivity to erotic pictures in the left orbitofrontal cortex, left insula, and right ventral striatum. These results demonstrated a relationship between the BAS and reward sensitivity during the processing of erotic stimuli, filling the gap of previous reports that identified the dopaminergic system as a neural substrate for the BAS during the processing of other rewarding stimuli such as money and food.

  18. Monetary reward speeds up voluntary saccades.

    Science.gov (United States)

    Chen, Lewis L; Chen, Y Mark; Zhou, Wu; Mustain, William D

    2014-01-01

    Past studies have shown that reward contingency is critical for sensorimotor learning, and reward expectation speeds up saccades in animals. Whether monetary reward speeds up saccades in human remains unknown. Here we addressed this issue by employing a conditional saccade task, in which human subjects performed a series of non-reflexive, visually-guided horizontal saccades. The subjects were (or were not) financially compensated for making a saccade in response to a centrally-displayed visual congruent (or incongruent) stimulus. Reward modulation of saccadic velocities was quantified independently of the amplitude-velocity coupling. We found that reward expectation significantly sped up voluntary saccades up to 30°/s, and the reward modulation was consistent across tests. These findings suggest that monetary reward speeds up saccades in human in a fashion analogous to how juice reward sped up saccades in monkeys. We further noticed that the idiosyncratic nasal-temporal velocity asymmetry was highly consistent regardless of test order, and its magnitude was not correlated with the magnitude of reward modulation. This suggests that reward modulation and the intrinsic velocity asymmetry may be governed by separate mechanisms that regulate saccade generation.

  19. Reward system dysfunction in autism spectrum disorders

    Science.gov (United States)

    Schulte-Rüther, Martin; Nehrkorn, Barbara; Müller, Kristin; Fink, Gereon R.; Kamp-Becker, Inge; Herpertz-Dahlmann, Beate; Schultz, Robert T.; Konrad, Kerstin

    2013-01-01

    Although it has been suggested that social deficits of autism spectrum disorders (ASDs) are related to reward circuitry dysfunction, very little is known about the neural reward mechanisms in ASD. In the current functional magnetic resonance imaging study, we investigated brain activations in response to both social and monetary reward in a group of children with ASD, relative to matched controls. Participants with ASD showed the expected hypoactivation in the mesocorticolimbic circuitry in response to both reward types. In particular, diminished activation in the nucleus accumbens was observed when money, but not when social reward, was at stake, whereas the amygdala and anterior cingulate cortex were hypoactivated within the ASD group in response to both rewards. These data indicate that the reward circuitry is compromised in ASD in social as well as in non-social, i.e. monetary conditions, which likely contributes to atypical motivated behaviour. Taken together, with incentives used in this study sample, there is evidence for a general reward dysfunction in ASD. However, more ecologically valid social reward paradigms are needed to fully understand, whether there is any domain specificity to the reward deficit that appears evident in ASD, which would be most consistent with the ASD social phenotype. PMID:22419119

  20. Memory Consolidation and Neural Substrate of Reward

    Directory of Open Access Journals (Sweden)

    Redolar-Ripoll, Diego

    2012-08-01

    Full Text Available The aim of this report is to analyze the relationships between reward and learning and memory processes. Different studies have described how information about rewards influences behavior and how the brain uses this reward information to control learning and memory processes. Reward nature seems to be processed in different ways by neurons in different brain structures, ranging from the detection and perception of rewards to the use of information about predicted rewards for the control of goal-directed behavior. The neural substrate underling this processing of reward information is a reliable way of improving learning and memory processes. Evidence from several studies indicates that this neural system can facilitate memory consolidation in a wide variety of learning tasks. From a molecular perspective, certain cardinal features of reward have been described as forms of memory. Studies of human addicts and studies in animal models of addiction show that chronic drug exposure produces stable changes in the brain at the cellular and molecular levels that underlie the long-lasting behavioral plasticity associated with addiction. These molecular and cellular adaptations involved in addiction are also implicated in learning and memory processes. Dopamine seems to be a critical common signal to activate different genetic mechanisms that ultimately remodel synapses and circuits. Despite memory is an active and complex process mediated by different brain areas, the neural substrate of reward is able to improve memory consolidation in a several paradigms. We believe that there are many equivalent traits between reward and learning and memory processes.

  1. Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting.

    Science.gov (United States)

    Negash, Sesen; Sheppard, Nicole Van Ness; Lambert, Nathaniel M; Fincham, Frank D

    2016-01-01

    Internet pornography is a multi-billion-dollar industry that has grown increasingly accessible. Delay discounting involves devaluing larger, later rewards in favor of smaller, more immediate rewards. The constant novelty and primacy of sexual stimuli as particularly strong natural rewards make Internet pornography a unique activator of the brain's reward system, thereby having implications for decision-making processes. Based on theoretical studies of evolutionary psychology and neuroeconomics, two studies tested the hypothesis that consuming Internet pornography would relate to higher rates of delay discounting. Study 1 used a longitudinal design. Participants completed a pornography use questionnaire and a delay discounting task at Time 1 and then again four weeks later. Participants reporting higher initial pornography use demonstrated a higher delay discounting rate at Time 2, controlling for initial delay discounting. Study 2 tested for causality with an experimental design. Participants were randomly assigned to abstain from either their favorite food or pornography for three weeks. Participants who abstained from pornography use demonstrated lower delay discounting than participants who abstained from their favorite food. The finding suggests that Internet pornography is a sexual reward that contributes to delay discounting differently than other natural rewards. Theoretical and clinical implications of these studies are highlighted.

  2. The habenula governs the attribution of incentive salience to reward predictive cues

    Science.gov (United States)

    Danna, Carey L.; Shepard, Paul D.; Elmer, Greg I.

    2013-01-01

    The attribution of incentive salience to reward associated cues is critical for motivation and the pursuit of rewards. Disruptions in the integrity of the neural systems controlling these processes can lead to avolition and anhedonia, symptoms that cross the diagnostic boundaries of many neuropsychiatric illnesses. Here, we consider whether the habenula (Hb), a region recently demonstrated to encode negatively valenced events, also modulates the attribution of incentive salience to a neutral cue predicting a food reward. The Pavlovian autoshaping paradigm was used in the rat as an investigative tool to dissociate Pavlovian learning processes imparting strictly predictive value from learning that attributes incentive motivational value. Electrolytic lesions of the fasciculus retroflexus (fr), the sole pathway through which descending Hb efferents are conveyed, significantly increased incentive salience as measured by conditioned approaches to a cue light predictive of reward. Conversely, generation of a fictive Hb signal via fr stimulation during CS+ presentation significantly decreased the incentive salience of the predictive cue. Neither manipulation altered the reward predictive value of the cue as measured by conditioned approach to the food. Our results provide new evidence supporting a significant role for the Hb in governing the attribution of incentive motivational salience to reward predictive cues and further imply that pathological changes in Hb activity could contribute to the aberrant pursuit of debilitating goals or avolition and depression-like symptoms. PMID:24368898

  3. The habenula governs the attribution of incentive salience to reward predictive cues.

    Directory of Open Access Journals (Sweden)

    Carey L. Danna

    2013-12-01

    Full Text Available The attribution of incentive salience to reward associated cues is critical for motivation and the pursuit of rewards. Disruptions in the integrity of the neural systems controlling these processes can lead to avolition and anhedonia, symptoms that cross the diagnostic boundaries of many neuropsychiatric illnesses. Here, we consider whether the habenula (Hb, a region recently demonstrated to encode negatively valenced events, also modulates the attribution of incentive salience to a neutral cue predicting a food reward. The Pavlovian autoshaping paradigm was used in the rat as an investigative tool to dissociate Pavlovian learning processes imparting strictly predictive value from learning that attributes incentive motivational value. Electrolytic lesions of the fasciculus retroflexus (fr, the sole pathway through which descending Hb efferents are conveyed, significantly increased incentive salience as measured by conditioned approaches to a cue light predictive of reward. Conversely, generation of a fictive Hb signal via fr stimulation during CS+ presentation significantly decreased the incentive salience of the predictive cue. Neither manipulation altered the reward predictive value of the cue as measured by conditioned approach to the food. Our results provide new evidence supporting a significant role for the Hb in governing the attribution of incentive motivational salience to reward predictive cues and further imply that pathological changes in Hb activity could contribute to the aberrant pursuit of debilitating goals or avolition and depression-like symptoms.

  4. Fitting Hidden Markov Models to Psychological Data

    Directory of Open Access Journals (Sweden)

    Ingmar Visser

    2002-01-01

    Full Text Available Markov models have been used extensively in psychology of learning. Applications of hidden Markov models are rare however. This is partially due to the fact that comprehensive statistics for model selection and model assessment are lacking in the psychological literature. We present model selection and model assessment statistics that are particularly useful in applying hidden Markov models in psychology. These statistics are presented and evaluated by simulation studies for a toy example. We compare AIC, BIC and related criteria and introduce a prediction error measure for assessing goodness-of-fit. In a simulation study, two methods of fitting equality constraints are compared. In two illustrative examples with experimental data we apply selection criteria, fit models with constraints and assess goodness-of-fit. First, data from a concept identification task is analyzed. Hidden Markov models provide a flexible approach to analyzing such data when compared to other modeling methods. Second, a novel application of hidden Markov models in implicit learning is presented. Hidden Markov models are used in this context to quantify knowledge that subjects express in an implicit learning task. This method of analyzing implicit learning data provides a comprehensive approach for addressing important theoretical issues in the field.

  5. Geometric phases and hidden local gauge symmetry

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo

    2005-01-01

    The analysis of geometric phases associated with level crossing is reduced to the familiar diagonalization of the Hamiltonian in the second quantized formulation. A hidden local gauge symmetry, which is associated with the arbitrariness of the phase choice of a complete orthonormal basis set, becomes explicit in this formulation (in particular, in the adiabatic approximation) and specifies physical observables. The choice of a basis set which specifies the coordinate in the functional space is arbitrary in the second quantization, and a subclass of coordinate transformations, which keeps the form of the action invariant, is recognized as the gauge symmetry. We discuss the implications of this hidden local gauge symmetry in detail by analyzing geometric phases for cyclic and noncyclic evolutions. It is shown that the hidden local symmetry provides a basic concept alternative to the notion of holonomy to analyze geometric phases and that the analysis based on the hidden local gauge symmetry leads to results consistent with the general prescription of Pancharatnam. We however note an important difference between the geometric phases for cyclic and noncyclic evolutions. We also explain a basic difference between our hidden local gauge symmetry and a gauge symmetry (or equivalence class) used by Aharonov and Anandan in their definition of generalized geometric phases

  6. Role of ghrelin in drug abuse and reward-relevant behaviors: a burgeoning field and gaps in the literature.

    Science.gov (United States)

    Revitsky, A R; Klein, L C

    2013-09-01

    Ghrelin is a gut-brain hormone that regulates energy balance through food consumption. While ghrelin is well known for its role in hypothalamic activation and homeostatic feeding, more recent evidence suggests that ghrelin also is involved in hedonic feeding through the dopaminergic reward pathway. This paper investigated how ghrelin administration (intraperitoneal, intracerebroventricular, or directly into dopaminergic reward-relevant brain regions) activates the dopaminergic reward pathway and associated reward-relevant behavioral responses in rodents. A total of 19 empirical publications that examined one or more of these variables were included in this review. Overall, ghrelin administration increases dopamine levels in the nucleus accumbens, as well as reward-relevant behaviors such as food (both standard chow and palatable foods) and alcohol consumption. Ghrelin administration also increases operant responding for sucrose, and conditioned place preference. Following a review of the small body of literature examining the effects of ghrelin administration on the dopamine reward pathway, we present a model of the relationship between ghrelin and dopaminergic reward activation. Specifically, ghrelin acts on ghrelin receptors (GHS-R1A) in the ventral tegmental area (VTA) and lateral dorsal tegmental nucleus (LDTg) to stimulate the mesolimbic dopamine reward pathway, which results in increased rewarding behaviors in rodents. Results from this review suggest that selective antagonism of the ghrelin system may serve as potential treatment for addictive drug use. This review highlights gaps in the literature, including a lack of examination of sex- or age-related differences in the effects of ghrelin on dopamine reward processes. In light of vulnerability to drug abuse among female and adolescent populations, future studies should target these individual difference factors.

  7. The reward-based eating drive scale: a self-report index of reward-based eating.

    Directory of Open Access Journals (Sweden)

    Elissa S Epel

    Full Text Available Why are some individuals more vulnerable to persistent weight gain and obesity than are others? Some obese individuals report factors that drive overeating, including lack of control, lack of satiation, and preoccupation with food, which may stem from reward-related neural circuitry. These are normative and common symptoms and not the sole focus of any existing measures. Many eating scales capture these common behaviors, but are confounded with aspects of dysregulated eating such as binge eating or emotional overeating. Across five studies, we developed items that capture this reward-based eating drive (RED. Study 1 developed the items in lean to obese individuals (n = 327 and examined changes in weight over eight years. In Study 2, the scale was further developed and expert raters evaluated the set of items. Study 3 tested psychometric properties of the final 9 items in 400 participants. Study 4 examined psychometric properties and race invariance (n = 80 women. Study 5 examined psychometric properties and age/gender invariance (n = 381. Results showed that RED scores correlated with BMI and predicted earlier onset of obesity, greater weight fluctuations, and greater overall weight gain over eight years. Expert ratings of RED scale items indicated that the items reflected characteristics of reward-based eating. The RED scale evidenced high internal consistency and invariance across demographic factors. The RED scale, designed to tap vulnerability to reward-based eating behavior, appears to be a useful brief tool for identifying those at higher risk of weight gain over time. Given the heterogeneity of obesity, unique brief profiling of the reward-based aspect of obesity using a self-report instrument such as the RED scale may be critical for customizing effective treatments in the general population.

  8. Analysis of changing hidden energy flow in Vietnam

    International Nuclear Information System (INIS)

    Nguyen Thi Anh Tuyet; Ishihara, Keiichi N.

    2006-01-01

    The energy consumption in production process is changing especially in developing countries by substituting technology. Input-output analysis for energy flows has been developing and is one of the best solutions for investigating macroscopic exchanges of both economy and energy. Since each element in the Leontief inverse contains both direct and indirect effects of any change in final demand, to separate those direct and indirect effects, the power series expansion is available. In this work, the changes of embodied energy intensity in Vietnam from 1996 to 2000 were analyzed using the structural decomposition and its power series expansion. By illustrating the change of causal relationship between direct energy consumption and embodied energy consumption, the change of hidden energy flow, which indicates how the changing embodied energy builds up the change of direct energy consumption in every sector, can be seen. In the case study, the rice processing sector, which is one of the important food processing sectors in Vietnam, is focused. By drawing a diagrammatic map for the change of hidden energy flow, it is clarified that in the case of raising embodied energy intensity, cultivation sector and trade and repaired service sector are the main contributors, and, on the contrary, in the case of reducing embodied energy intensity, paper pulp sector is the main contributor

  9. Massive hidden photons as lukewarm dark matter

    International Nuclear Information System (INIS)

    Redondo, Javier; Postma, Marieke

    2008-11-01

    We study the possibility that a keV-MeV mass hidden photon (HP), i.e. a hidden sector U(1) gauge boson, accounts for the observed amount of dark matter. We focus on the case where the HP interacts with the standard model sector only through kinetic mixing with the photon. The relic abundance is computed including all relevant plasma effects into the photon's self-energy, which leads to a resonant yield almost independent of the HP mass. The HP can decay into three photons. Moreover, if light enough it can be copiously produced in stars. Including bounds from cosmic photon backgrounds and stellar evolution, we find that the hidden photon can only give a subdominant contribution to the dark matter. This negative conclusion may be avoided if another production mechanism besides kinetic mixing is operative. (orig.)

  10. Massive hidden photons as lukewarm dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Postma, Marieke [Nationaal Inst. voor Kernfysica en Hoge-Energiefysica (NIKHEF), Amsterdam (Netherlands)

    2008-11-15

    We study the possibility that a keV-MeV mass hidden photon (HP), i.e. a hidden sector U(1) gauge boson, accounts for the observed amount of dark matter. We focus on the case where the HP interacts with the standard model sector only through kinetic mixing with the photon. The relic abundance is computed including all relevant plasma effects into the photon's self-energy, which leads to a resonant yield almost independent of the HP mass. The HP can decay into three photons. Moreover, if light enough it can be copiously produced in stars. Including bounds from cosmic photon backgrounds and stellar evolution, we find that the hidden photon can only give a subdominant contribution to the dark matter. This negative conclusion may be avoided if another production mechanism besides kinetic mixing is operative. (orig.)

  11. Religious Tolerance in the Hidden Curriculum

    Directory of Open Access Journals (Sweden)

    Kevin Nobel Kurniawan

    2018-03-01

    Full Text Available Religious intolerance is spreading within the Indonesian institution of education. Previous studies have shown that the growth of intolerance is due to the state’s regulation and pedagogical apparatus. In contrast to the previous studies, I argue that the intolerance is related to hidden curriculum applied by the institution of education.  Normatively, the hidden curriculum contains the value of religious tolerance. However, factually, the author found that there are practices of intolerance, through the formal and informal spheres in the school’s structure, within the hidden curriculum. This article applies a qualitative approach with a mixed method research strategy to analyze data collected from students, teachers, and alumnis through field observation, in-depth interview, and survey.

  12. Endogenous nociceptin modulates diet preference independent of motivation and reward.

    Science.gov (United States)

    Koizumi, Miwako; Cagniard, Barbara; Murphy, Niall P

    2009-04-20

    Previous studies show that the opioid peptide nociceptin stimulates food intake. Here, we studied nociceptin receptor knockout (NOP KO) mice in various behavioral paradigms designed to differentiate psychological and physiological loci at which endogenous nociceptin might control feeding. When presented a choice under food restriction, NOP KO mice displayed reduced preference for high sucrose diet, but lower intake of high fat diet under no-choice conditions. These responses were absent under ad libitum feeding conditions. Conditioned place preference to high fat diet under food-deprived conditions was unaltered in NOP KO mice, suggesting no difference in reward responses. Furthermore, operant food self-administration under a variety of conditions showed no genotype-dependent differences, suggesting no differences in the motivational properties of food. Taste reactivity to sucrose was unchanged in NOP KO mice, though NOP KO mice had altered aversive reactions to quinine solutions under ad libitum feeding, suggesting minor differences in the affective impact of palatable and unpalatable tastants. Although NOP KO mice re-fed following food-deprivation showed normal increases in plasma glucose and insulin, multidimensional scaling analysis showed that the relationship between these measures, body weight and plasma leptin was substantially disrupted in NOP KO, particularly in fasted mice. Additionally, the typical positive relationship between body weight and plasma leptin was considerably weaker in NOP KO mice. Together, these findings suggest that endogenous nociceptin differentially modulates diet preference depending on macronutrient content and homeostatic state, independently of the motivating, rewarding or orosensory properties of food, but may involve metabolic or postingestive processes.

  13. Learning Reward Uncertainty in the Basal Ganglia.

    Directory of Open Access Journals (Sweden)

    John G Mikhael

    2016-09-01

    Full Text Available Learning the reliability of different sources of rewards is critical for making optimal choices. However, despite the existence of detailed theory describing how the expected reward is learned in the basal ganglia, it is not known how reward uncertainty is estimated in these circuits. This paper presents a class of models that encode both the mean reward and the spread of the rewards, the former in the difference between the synaptic weights of D1 and D2 neurons, and the latter in their sum. In the models, the tendency to seek (or avoid options with variable reward can be controlled by increasing (or decreasing the tonic level of dopamine. The models are consistent with the physiology of and synaptic plasticity in the basal ganglia, they explain the effects of dopaminergic manipulations on choices involving risks, and they make multiple experimental predictions.

  14. Hidden treasures - 50 km points of interests

    Science.gov (United States)

    Lommi, Matias; Kortelainen, Jaana

    2015-04-01

    Tampere is third largest city in Finland and a regional centre. During 70's there occurred several communal mergers. Nowadays this local area has both strong and diversed identity - from wilderness and agricultural fields to high density city living. Outside the city center there are interesting geological points unknown for modern city settlers. There is even a local proverb, "Go abroad to Teisko!". That is the area the Hidden Treasures -student project is focused on. Our school Tammerkoski Upper Secondary School (or Gymnasium) has emphasis on visual arts. We are going to offer our art students scientific and artistic experiences and knowledge about the hidden treasures of Teisko area and involve the Teisko inhabitants into this project. Hidden treasures - Precambrian subduction zone and a volcanism belt with dense bed of gold (Au) and arsenic (As), operating goldmines and quarries of minerals and metamorphic slates. - North of subduction zone a homogenic precambrian magmastone area with quarries, products known as Kuru Grey. - Former ashores of post-glasial Lake Näsijärvi and it's sediments enabled the developing agriculture and sustained settlement. Nowadays these ashores have both scenery and biodiversity values. - Old cattle sheds and dairy buildings made of local granite stones related to cultural stonebuilding inheritance. - Local active community of Kapee, about 100 inhabitants. Students will discover information of these "hidden" phenomena, and rendering this information trough Enviromental Art Method. Final form of this project will be published in several artistic and informative geocaches. These caches are achieved by a GPS-based special Hidden Treasures Cycling Route and by a website guiding people to find these hidden points of interests.

  15. Reward disrupts reactivated human skill memory

    OpenAIRE

    Dayan, Eran; Laor-Maayany, Rony; Censor, Nitzan

    2016-01-01

    Accumulating evidence across species and memory domains shows that when an existing memory is reactivated, it becomes susceptible to modifications. However, the potential role of reward signals in these mechanisms underlying human memory dynamics is unknown. Leaning on a wealth of findings on the role of reward in reinforcing memory, we tested the impact of reinforcing a skill memory trace with monetary reward following memory reactivation, on strengthening of the memory trace. Reinforcing re...

  16. An expert system for reward systems design.

    OpenAIRE

    Erturk, Alper

    2000-01-01

    Approved for public release; distribution is unlimited Today's business environment is a highly competitive marketplace. In this competition, organizations distribute numerous rewards to motivate, attract and retain employees, such as pay, fringe benefits and promotions. However, not all managers have the necessary knowledge and expertise to effectively decide and structure reward systems. This thesis presents an expert system to assist managers with designing the most appropriate reward s...

  17. The origin of the hidden supersymmetry

    International Nuclear Information System (INIS)

    Jakubsky, Vit; Nieto, Luis-Miguel; Plyushchay, Mikhail S.

    2010-01-01

    The hidden supersymmetry and related tri-supersymmetric structure of the free particle system, the Dirac delta potential problem and the Aharonov-Bohm effect (planar, bound state, and tubule models) are explained by a special nonlocal unitary transformation, which for the usual N=2 supercharges has a nature of Foldy-Wouthuysen transformation. We show that in general case, the bosonized supersymmetry of nonlocal, parity even systems emerges in the same construction, and explain the origin of the unusual N=2 supersymmetry of electron in three-dimensional parity even magnetic field. The observation extends to include the hidden superconformal symmetry.

  18. Signatures of a hidden cosmic microwave background.

    Science.gov (United States)

    Jaeckel, Joerg; Redondo, Javier; Ringwald, Andreas

    2008-09-26

    If there is a light Abelian gauge boson gamma' in the hidden sector its kinetic mixing with the photon can produce a hidden cosmic microwave background (HCMB). For meV masses, resonant oscillations gammagamma' happen after big bang nucleosynthesis (BBN) but before CMB decoupling, increasing the effective number of neutrinos Nnu(eff) and the baryon to photon ratio, and distorting the CMB blackbody spectrum. The agreement between BBN and CMB data provides new constraints. However, including Lyman-alpha data, Nnu(eff) > 3 is preferred. It is tempting to attribute this effect to the HCMB. The interesting parameter range will be tested in upcoming laboratory experiments.

  19. Hidden simplicity of gauge theory amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, J M, E-mail: drummond@lapp.in2p3.f [LAPTH, Universite de Savoie, CNRS, B.P. 110, F-74941 Annecy-le-Vieux, Cedex (France)

    2010-11-07

    These notes were given as lectures at the CERN Winter School on Supergravity, Strings and Gauge Theory 2010. We describe the structure of scattering amplitudes in gauge theories, focussing on the maximally supersymmetric theory to highlight the hidden symmetries which appear. Using the Britto, Cachzo, Feng and Witten (BCFW) recursion relations we solve the tree-level S-matrix in N=4 super Yang-Mills theory and describe how it produces a sum of invariants of a large symmetry algebra. We review amplitudes in the planar theory beyond tree level, describing the connection between amplitudes and Wilson loops, and discuss the implications of the hidden symmetries.

  20. A balance of activity in brain control and reward systems predicts self-regulatory outcomes.

    Science.gov (United States)

    Lopez, Richard B; Chen, Pin-Hao A; Huckins, Jeremy F; Hofmann, Wilhelm; Kelley, William M; Heatherton, Todd F

    2017-05-01

    Previous neuroimaging work has shown that increased reward-related activity following exposure to food cues is predictive of self-control failure. The balance model suggests that self-regulation failures result from an imbalance in reward and executive control mechanisms. However, an open question is whether the relative balance of activity in brain systems associated with executive control (vs reward) supports self-regulatory outcomes when people encounter tempting cues in daily life. Sixty-nine chronic dieters, a population known for frequent lapses in self-control, completed a food cue-reactivity task during an fMRI scanning session, followed by a weeklong sampling of daily eating behaviors via ecological momentary assessment. We related participants' food cue activity in brain systems associated with executive control and reward to real-world eating patterns. Specifically, a balance score representing the amount of activity in brain regions associated with self-regulatory control, relative to automatic reward-related activity, predicted dieters' control over their eating behavior during the following week. This balance measure may reflect individual self-control capacity and be useful for examining self-regulation success in other domains and populations. © The Author (2017). Published by Oxford University Press.

  1. Regulation of brain reward by the endocannabinoid system: a critical review of behavioral studies in animals.

    Science.gov (United States)

    Vlachou, S; Panagis, G

    2014-01-01

    The endocannabinoid system has been implicated in the regulation of a variety of physiological processes, including a crucial involvement in brain reward systems and the regulation of motivational processes. Behavioral studies have shown that cannabinoid reward may involve the same brain circuits and similar brain mechanisms with other drugs of abuse, such as nicotine, cocaine, alcohol and heroin, as well as natural rewards, such as food, water and sucrose, although the conditions under which cannabinoids exert their rewarding effects may be more limited. The purpose of the present review is to briefly describe and evaluate the behavioral and pharmacological research concerning the major components of the endocannabinoid system and reward processes. Special emphasis is placed on data received from four procedures used to test the effects of the endocannabinoid system on brain reward in animals; namely, the intracranial self-stimulation paradigm, the self-administration procedure, the conditioned place preference procedure and the drug-discrimination procedure. The effects of cannabinoid 1 (CB1) and cannabinoid 2 (CB2) receptor agonists, antagonists and endocannabinoid modulators in these procedures are examined. Further, the involvement of CB1 and CB2 receptors, as well the fatty acid amid hydrolase (FAAH) enzyme in reward processes is investigated through presentation of respective genetic ablation studies in mice. We suggest that the endocannabinoid system plays a major role in modulating motivation and reward processes. Further research will provide us with a better understanding of these processes and, thus, could lead to the development of potential therapeutic compounds for the treatment of reward-related disorders.

  2. Self-stimulating rats combine subjective reward magnitude and subjective reward rate multiplicatively.

    Science.gov (United States)

    Leon, M I; Gallistel, C R

    1998-07-01

    For rats that bar pressed for intracranial electrical stimulation in a 2-lever matching paradigm with concurrent variable interval schedules of reward, the authors found that the time allocation ratio is based on a multiplicative combination of the ratio of subjective reward magnitudes and the ratio of the rates of reward. Multiplicative combining was observed in a range covering approximately 2 orders of magnitude in the ratio of the rates of reward from about 1:10 to 10:1) and an order of magnitude change in the size of rewards. After determining the relation between the pulse frequency of stimulation and subjective reward magnitude, the authors were able to predict from knowledge of the subjective magnitudes of the rewards and the obtained relative rates of reward the subject's time allocation ratio over a range in which it varied by more than 3 orders of magnitude.

  3. The role of sweet and savoury taste in food intake and food preferences

    NARCIS (Netherlands)

    Griffioen-Roose, S.

    2012-01-01

    Background and aim

    The sensory attributes of food play a key role in the selection and termination of meals and their rewarding properties. The majority of our foods are either sweet or savoury tasting. In addition, within our food range, savoury-tasting foods contain in

  4. An Expert System for Reward Systems Design

    National Research Council Canada - National Science Library

    Erturk, Alper

    2000-01-01

    Today's business environment is a highly competitive marketplace. In this competition, organizations distribute numerous rewards to motivate, attract and retain employees, such as pay, fringe benefits and promotions...

  5. Neural processing of reward in adolescent rodents

    Directory of Open Access Journals (Sweden)

    Nicholas W. Simon

    2015-02-01

    Full Text Available Immaturities in adolescent reward processing are thought to contribute to poor decision making and increased susceptibility to develop addictive and psychiatric disorders. Very little is known; however, about how the adolescent brain processes reward. The current mechanistic theories of reward processing are derived from adult models. Here we review recent research focused on understanding of how the adolescent brain responds to rewards and reward-associated events. A critical aspect of this work is that age-related differences are evident in neuronal processing of reward-related events across multiple brain regions even when adolescent rats demonstrate behavior similar to adults. These include differences in reward processing between adolescent and adult rats in orbitofrontal cortex and dorsal striatum. Surprisingly, minimal age related differences are observed in ventral striatum, which has been a focal point of developmental studies. We go on to discuss the implications of these differences for behavioral traits affected in adolescence, such as impulsivity, risk-taking, and behavioral flexibility. Collectively, this work suggests that reward-evoked neural activity differs as a function of age and that regions such as the dorsal striatum that are not traditionally associated with affective processing in adults may be critical for reward processing and psychiatric vulnerability in adolescents.

  6. Food-Related Odors Activate Dopaminergic Brain Areas

    OpenAIRE

    Agnieszka Sorokowska; Agnieszka Sorokowska; Katherina Schoen; Cornelia Hummel; Pengfei Han; Jonathan Warr; Thomas Hummel

    2017-01-01

    Food-associated cues of different sensory categories have often been shown to be a potent elicitor of cerebral activity in brain reward circuits. Smells influence and modify the hedonic qualities of eating experience, and in contrast to smells not associated with food, perception of food-associated odors may activate dopaminergic brain areas. In this study, we aimed to verify previous findings related to the rewarding value of food-associated odors by means of an fMRI design involving careful...

  7. Searching for hidden sectors in multiparticle production at the LHC

    CERN Document Server

    Sanchis-Lozano, Miguel-Angel; Moreno-Picot, Salvador

    2016-01-01

    We study the impact of a hidden sector beyond the Standard Model, e.g. a Hidden Valley model, on factorial moments and cumulants of multiplicity distributions in multiparticle production with a special emphasis on the prospects for LHC results.

  8. Social Influences on Creativity: Interactive Effects of Reward and Choice.

    Science.gov (United States)

    Amabile, Teresa M.

    In a test of intrinsic motivation hypothesis of creativity, 60 undergraduate women did an artistic creativity task with either the expectation of receiving a reward or no expectation of reward. Reward was crossed with choice in task engagement, such that half of the reward Ss contracted to do the task in order to receive reward, and half simply…

  9. Neural activation to monetary reward is associated with amphetamine reward sensitivity.

    Science.gov (United States)

    Crane, Natania A; Gorka, Stephanie M; Weafer, Jessica; Langenecker, Scott A; de Wit, Harriet; Phan, K Luan

    2018-03-14

    One known risk factor for drug use and abuse is sensitivity to rewarding effects of drugs. It is not known whether this risk factor extends to sensitivity to non-drug rewards. In this study with healthy young adults, we examined the association between sensitivity to the subjective rewarding effects of amphetamine and a neural indicator of anticipation of monetary reward. We hypothesized that greater euphorigenic response to amphetamine would be associated with greater neural activation to anticipation of monetary reward (Win > Loss). Healthy participants (N = 61) completed four laboratory sessions in which they received d-amphetamine (20 mg) and placebo in alternating order, providing self-report measures of euphoria and stimulation at regular intervals. At a separate visit 1-3 weeks later, participants completed the guessing reward task (GRT) during fMRI in a drug-free state. Participants reporting greater euphoria after amphetamine also exhibited greater neural activation during monetary reward anticipation in mesolimbic reward regions, including the bilateral caudate and putamen. This is the first study to show a relationship between neural correlates of monetary reward and sensitivity to the subjective rewarding effects of amphetamine in humans. These findings support growing evidence that sensitivity to reward in general is a risk factor for drug use and abuse, and suggest that sensitivity of drug-induced euphoria may reflect a general sensitivity to rewards. This may be an index of vulnerability for drug use or abuse.

  10. Major depressive disorder is characterized by greater reward network activation to monetary than pleasant image rewards.

    Science.gov (United States)

    Smoski, Moria J; Rittenberg, Alison; Dichter, Gabriel S

    2011-12-30

    Anhedonia, the loss of interest or pleasure in normally rewarding activities, is a hallmark feature of unipolar Major Depressive Disorder (MDD). A growing body of literature has identified frontostriatal dysfunction during reward anticipation and outcomes in MDD. However, no study to date has directly compared responses to different types of rewards such as pleasant images and monetary rewards in MDD. To investigate the neural responses to monetary and pleasant image rewards in MDD, a modified Monetary Incentive Delay task was used during functional magnetic resonance imaging to assess neural responses during anticipation and receipt of monetary and pleasant image rewards. Participants included nine adults with MDD and 13 affectively healthy controls. The MDD group showed lower activation than controls when anticipating monetary rewards in right orbitofrontal cortex and subcallosal cortex, and when anticipating pleasant image rewards in paracingulate and supplementary motor cortex. The MDD group had relatively greater activation in right putamen when anticipating monetary versus pleasant image rewards, relative to the control group. Results suggest reduced reward network activation in MDD when anticipating rewards, as well as relatively greater hypoactivation to pleasant image than monetary rewards. 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Random reward priming is task-contingent: The robustness of the 1-trial reward priming effect

    Directory of Open Access Journals (Sweden)

    Árni Gunnar Ásgeirsson

    2014-04-01

    Full Text Available Consistent financial reward of particular features influences the allocation of visual attention in many ways. More surprising are 1-trial reward priming effects on attention where reward schedules are random and reward on one trial influences attentional allocation on the next. Those findings are thought to reflect that rewarded features become more salient than unrewarded ones on the subsequent trial. Here we attempt to conceptually replicate this effect, testing its generalizability. In three versions of an analogous paradigm to the additional singleton paradigm involving singleton search for a Gabor patch of odd spatial frequency we found no evidence of reward priming, while we only partially replicate the reward priming in the exact original paradigm tested by Hickey and colleagues. The results cast doubt on the proposal that random reward enhances salience, suggested in the original papers, and highlight the need for a more nuanced account. In many other paradigms reward effects have been found to progress gradually, becoming stronger as they build up, and we argue that for robust reward priming, reward schedules need to be more consistent than in the original 1-trial reward priming paradigm.

  12. Compressing the hidden variable space of a qubit

    OpenAIRE

    Montina, Alberto

    2010-01-01

    In previously exhibited hidden variable models of quantum state preparation and measurement, the number of continuous hidden variables describing the actual state of a single realization is never smaller than the quantum state manifold dimension. We introduce a simple model for a qubit whose hidden variable space is one-dimensional, i.e., smaller than the two-dimensional Bloch sphere. The hidden variable probability distributions associated with the quantum states satisfy reasonable criteria ...

  13. Reward guides vision when it's your thing: trait reward-seeking in reward-mediated visual priming.

    Directory of Open Access Journals (Sweden)

    Clayton Hickey

    Full Text Available Reward-related mesolimbic dopamine is thought to play an important role in guiding animal behaviour, biasing approach towards potentially beneficial environmental stimuli and away from objects unlikely to garner positive outcome. This is considered to result in part from an impact on perceptual and attentional processes: dopamine initiates a series of cognitive events that result in the priming of reward-associated perceptual features. We have provided behavioural and electrophysiological evidence that this mechanism guides human vision in search, an effect we refer to as reward priming. We have also demonstrated that there is substantial individual variability in this effect. Here we show that behavioural differences in reward priming are predicted remarkably well by a personality index that captures the degree to which a person's behaviour is driven by reward outcome. Participants with reward-seeking personalities are found to be those who allocate visual resources to objects characterized by reward-associated visual features. These results add to a rapidly developing literature demonstrating the crucial role reward plays in attentional control. They additionally illustrate the striking impact personality traits can have on low-level cognitive processes like perception and selective attention.

  14. Reward-related behavioral paradigms for addiction research in the mouse: performance of common inbred strains.

    Directory of Open Access Journals (Sweden)

    Lauren Lederle

    2011-01-01

    Full Text Available The mouse has emerged as a uniquely valuable species for studying the molecular and genetic basis of complex behaviors and modeling neuropsychiatric disease states. While valid and reliable preclinical assays for reward-related behaviors are critical to understanding addiction-related processes, and various behavioral procedures have been developed and characterized in rats and primates, there have been relatively few studies using operant-based addiction-relevant behavioral paradigms in the mouse. Here we describe the performance of the C57BL/6J inbred mouse strain on three major reward-related paradigms, and replicate the same procedures in two other commonly used inbred strains (DBA/2J, BALB/cJ. We examined Pavlovian-instrumental transfer (PIT by measuring the ability of an auditory cue associated with food reward to promote an instrumental (lever press response. In a separate experiment, we assessed the acquisition and extinction of a simple stimulus-reward instrumental behavior on a touch screen based task. Reinstatement of this behavior was then examined following either continuous exposure to cues (conditioned reinforcers, CRs associated with reward, brief reward and CR exposure, or brief reward exposure followed by continuous CR exposure. The third paradigm examined sensitivity of an instrumental (lever press response to devaluation of food reward (a probe for outcome insensitive, habitual behavior by repeated pairing with malaise. Results showed that C57BL/6J mice displayed robust PIT, as well as clear extinction and reinstatement, but were insensitive to reinforcer devaluation. DBA/2J mice showed good PIT and (rewarded reinstatement, but were slow to extinguish and did not show reinforcer devaluation or significant CR-reinstatement. BALB/cJ mice also displayed good PIT, extinction and reinstatement, and retained instrumental responding following devaluation, but, unlike the other strains, demonstrated reduced Pavlovian approach

  15. Reward-related behavioral paradigms for addiction research in the mouse: performance of common inbred strains.

    Science.gov (United States)

    Lederle, Lauren; Weber, Susanna; Wright, Tara; Feyder, Michael; Brigman, Jonathan L; Crombag, Hans S; Saksida, Lisa M; Bussey, Timothy J; Holmes, Andrew

    2011-01-10

    The mouse has emerged as a uniquely valuable species for studying the molecular and genetic basis of complex behaviors and modeling neuropsychiatric disease states. While valid and reliable preclinical assays for reward-related behaviors are critical to understanding addiction-related processes, and various behavioral procedures have been developed and characterized in rats and primates, there have been relatively few studies using operant-based addiction-relevant behavioral paradigms in the mouse. Here we describe the performance of the C57BL/6J inbred mouse strain on three major reward-related paradigms, and replicate the same procedures in two other commonly used inbred strains (DBA/2J, BALB/cJ). We examined Pavlovian-instrumental transfer (PIT) by measuring the ability of an auditory cue associated with food reward to promote an instrumental (lever press) response. In a separate experiment, we assessed the acquisition and extinction of a simple stimulus-reward instrumental behavior on a touch screen based task. Reinstatement of this behavior was then examined following either continuous exposure to cues (conditioned reinforcers, CRs) associated with reward, brief reward and CR exposure, or brief reward exposure followed by continuous CR exposure. The third paradigm examined sensitivity of an instrumental (lever press) response to devaluation of food reward (a probe for outcome insensitive, habitual behavior) by repeated pairing with malaise. Results showed that C57BL/6J mice displayed robust PIT, as well as clear extinction and reinstatement, but were insensitive to reinforcer devaluation. DBA/2J mice showed good PIT and (rewarded) reinstatement, but were slow to extinguish and did not show reinforcer devaluation or significant CR-reinstatement. BALB/cJ mice also displayed good PIT, extinction and reinstatement, and retained instrumental responding following devaluation, but, unlike the other strains, demonstrated reduced Pavlovian approach behavior (food

  16. Hidden Markov Models for Human Genes

    DEFF Research Database (Denmark)

    Baldi, Pierre; Brunak, Søren; Chauvin, Yves

    1997-01-01

    We analyse the sequential structure of human genomic DNA by hidden Markov models. We apply models of widely different design: conventional left-right constructs and models with a built-in periodic architecture. The models are trained on segments of DNA sequences extracted such that they cover com...

  17. The Hidden Cost of Buying a Computer.

    Science.gov (United States)

    Johnson, Michael

    1983-01-01

    In order to process data in a computer, application software must be either developed or purchased. Costs for modifications of the software package and maintenance are often hidden. The decision to buy or develop software packages should be based upon factors of time and maintenance. (MLF)

  18. Hidden symmetries in five-dimensional supergravity

    International Nuclear Information System (INIS)

    Poessel, M.

    2003-05-01

    This thesis is concerned with the study of hidden symmetries in supergravity, which play an important role in the present picture of supergravity and string theory. Concretely, the appearance of a hidden G 2(+2) /SO(4) symmetry is studied in the dimensional reduction of d=5, N=2 supergravity to three dimensions - a parallel model to the more famous E 8(+8) /SO(16) case in eleven-dimensional supergravity. Extending previous partial results for the bosonic part, I give a derivation that includes fermionic terms. This sheds new light on the appearance of the local hidden symmetry SO(4) in the reduction, and shows up an unusual feature which follows from an analysis of the R-symmetry associated with N=4 supergravity and of the supersymmetry variations, and which has no parallel in the eleven-dimensional case: The emergence of an additional SO(3) as part of the enhanced local symmetry, invisible in the dimensional reduction of the gravitino, and corresponding to the fact that, of the SO(4) used in the coset model, only the diagonal SO(3) is visible immediately upon dimensional reduction. The uncovering of the hidden symmetries proceeds via the construction of the proper coset gravity in three dimensions, and matching it with the Lagrangian obtained from the reduction. (orig.)

  19. Discovering hidden sectors with monophoton Z' searches

    International Nuclear Information System (INIS)

    Gershtein, Yuri; Petriello, Frank; Quackenbush, Seth; Zurek, Kathryn M.

    2008-01-01

    In many theories of physics beyond the standard model, from extra dimensions to Hidden Valleys and models of dark matter, Z ' bosons mediate between standard model particles and hidden sector states. We study the feasibility of observing such hidden states through an invisibly decaying Z ' at the LHC. We focus on the process pp→γZ ' →γXX † , where X is any neutral, (quasi-) stable particle, whether a standard model neutrino or a new state. This complements a previous study using pp→ZZ ' →l + l - XX † . Only the Z ' mass and two effective charges are needed to describe this process. If the Z ' decays invisibly only to standard model neutrinos, then these charges are predicted by observation of the Z ' through the Drell-Yan process, allowing discrimination between Z ' decays to standard model ν's and invisible decays to new states. We carefully discuss all backgrounds and systematic errors that affect this search. We find that hidden sector decays of a 1 TeV Z ' can be observed at 5σ significance with 50 fb -1 at the LHC. Observation of a 1.5 TeV state requires super-LHC statistics of 1 ab -1 . Control of the systematic errors, in particular, the parton distribution function uncertainty of the dominant Zγ background, is crucial to maximize the LHC search reach.

  20. Hidden Markov models for labeled sequences

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose

    1994-01-01

    A hidden Markov model for labeled observations, called a class HMM, is introduced and a maximum likelihood method is developed for estimating the parameters of the model. Instead of training it to model the statistics of the training sequences it is trained to optimize recognition. It resembles MMI...

  1. Environmental manipulations alter age differences in attribution of incentive salience to reward-paired cues.

    Science.gov (United States)

    Anderson, Rachel I; Bush, Peter C; Spear, Linda P

    2013-11-15

    Cues repeatedly paired with rewards often themselves become imbued with enhanced motivational value, or incentive salience. During Pavlovian conditioned approach procedures, a cue repeatedly preceding reward delivery often elicits conditioned responses at either the reward delivery location ("goal-tracking") or the cue itself ("sign-tracking"). Sign-tracking behavior is thought to reflect the individual differences in attribution of incentive salience to reward-paired cues that may contribute to addiction vulnerability. Adolescent rats typically demonstrate less sign-tracking behavior than adult rats, a surprising finding given that adolescence is hypothesized to be a time of heightened addiction vulnerability. Given evidence that adult sign-tracking behavior can be influenced by environmental conditions, the present study compared the effects of isolate housing and food deprivation on expression of sign-tacking and goal-tracking behavior in adolescent and adult male rats across eight days of a Pavlovian conditioned approach procedure. Pair-housed adults exhibited more sign-tracking behavior than pair-housed adolescents; however, this age difference was not apparent in isolate-housed subjects. Adolescents often appeared more sensitive than adults to both food restriction- and isolate housing-induced changes in behavior, with food restriction promoting an increase in sign-tracking among isolate-housed adolescents and an increase in goal-tracking among pair-housed adolescents. For adults, food restriction resulted in a modest increase in overall expression of both sign- and goal-tracking behavior. To the extent that sign-tracking behavior reflects attribution of incentive salience to reward-paired cues, results from the present study provide evidence that reactivity to rewards during adolescence is strongly related to the nature of the surrounding environment. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Taking two to tango: a role for ghrelin receptor heterodimerization in stress and reward.

    Science.gov (United States)

    Schellekens, Harriët; Dinan, Timothy G; Cryan, John F

    2013-08-30

    The gut hormone, ghrelin, is the only known peripherally derived orexigenic signal. It activates its centrally expressed receptor, the growth hormone secretagogue receptor (GHS-R1a), to stimulate food intake. The ghrelin signaling system has recently been suggested to play a key role at the interface of homeostatic control of appetite and the hedonic aspects of food intake, as a critical role for ghrelin in dopaminergic mesolimbic circuits involved in reward signaling has emerged. Moreover, enhanced plasma ghrelin levels are associated with conditions of physiological stress, which may underline the drive to eat calorie-dense "comfort-foods" and signifies a role for ghrelin in stress-induced food reward behaviors. These complex and diverse functionalities of the ghrelinergic system are not yet fully elucidated and likely involve crosstalk with additional signaling systems. Interestingly, accumulating data over the last few years has shown the GHS-R1a receptor to dimerize with several additional G-protein coupled receptors (GPCRs) involved in appetite signaling and reward, including the GHS-R1b receptor, the melanocortin 3 receptor (MC3), dopamine receptors (D1 and D2), and more recently, the serotonin 2C receptor (5-HT2C). GHS-R1a dimerization was shown to affect downstream signaling and receptor trafficking suggesting a potential novel mechanism for fine-tuning GHS-R1a receptor mediated activity. This review summarizes ghrelin's role in food reward and stress and outlines the GHS-R1a dimer pairs identified to date. In addition, the downstream signaling and potential functional consequences of dimerization of the GHS-R1a receptor in appetite and stress-induced food reward behavior are discussed. The existence of multiple GHS-R1a heterodimers has important consequences for future pharmacotherapies as it significantly increases the pharmacological diversity of the GHS-R1a receptor and has the potential to enhance specificity of novel ghrelin-targeted drugs.

  3. Video game training and the reward system

    Science.gov (United States)

    Lorenz, Robert C.; Gleich, Tobias; Gallinat, Jürgen; Kühn, Simone

    2015-01-01

    Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual toward playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors in relation to video gaming experience as well as functional changes in the brain in response to video game training. Fifty healthy participants were randomly assigned to a video game training (TG) or control group (CG). Before and after training/control period, functional magnetic resonance imaging (fMRI) was conducted using a non-video game related reward task. At pretest, both groups showed strongest activation in ventral striatum (VS) during reward anticipation. At posttest, the TG showed very similar VS activity compared to pretest. In the CG, the VS activity was significantly attenuated. This longitudinal study revealed that video game training may preserve reward responsiveness in the VS in a retest situation over time. We suggest that video games are able to keep striatal responses to reward flexible, a mechanism which might be of critical value for applications such as therapeutic cognitive training. PMID:25698962

  4. Reward eliminates retrieval-induced forgetting.

    Science.gov (United States)

    Imai, Hisato; Kim, Dongho; Sasaki, Yuka; Watanabe, Takeo

    2014-12-02

    Although it is well known that reward enhances learning and memory, how extensively such enhancement occurs remains unclear. To address this question, we examined how reward influences retrieval-induced forgetting (RIF) in which the retrieval of a nonpracticed item under the same category as a practiced item is worse than the retrieval of a nonpracticed item outside the category. Subjects were asked to try to encode category-exemplar pairs (e.g., FISH-salmon). Then, they were presented with a category name and a two-letter word stem (e.g., FISH-sa) and were asked to complete an encoded word (retrieval practice). For a correct response, apple juice was given as a reward in the reward condition and a beeping sound was presented in the no-reward condition. Finally, subjects were asked to report whether each exemplar had been presented in the first phase. RIF was replicated in the no-reward condition. However, in the reward condition, RIF was eliminated. These results suggest that reward enhances processing of retrieval of unpracticed members by mechanisms such as spreading activation within the same category, irrespective of whether items were practiced or not.

  5. Video game training and the reward system.

    Science.gov (United States)

    Lorenz, Robert C; Gleich, Tobias; Gallinat, Jürgen; Kühn, Simone

    2015-01-01

    Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual toward playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors in relation to video gaming experience as well as functional changes in the brain in response to video game training. Fifty healthy participants were randomly assigned to a video game training (TG) or control group (CG). Before and after training/control period, functional magnetic resonance imaging (fMRI) was conducted using a non-video game related reward task. At pretest, both groups showed strongest activation in ventral striatum (VS) during reward anticipation. At posttest, the TG showed very similar VS activity compared to pretest. In the CG, the VS activity was significantly attenuated. This longitudinal study revealed that video game training may preserve reward responsiveness in the VS in a retest situation over time. We suggest that video games are able to keep striatal responses to reward flexible, a mechanism which might be of critical value for applications such as therapeutic cognitive training.

  6. Video Game Training and the Reward System

    Directory of Open Access Journals (Sweden)

    Robert C. Lorenz

    2015-02-01

    Full Text Available Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual towards playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors in relation to video gaming experience as well as functional changes in the brain in response to video game training.Fifty healthy participants were randomly assigned to a video game training (TG or control group (CG. Before and after training/control period, functional magnetic resonance imaging (fMRI was conducted using a non-video game related reward task.At pretest, both groups showed strongest activation in ventral striatum (VS during reward anticipation. At posttest, the TG showed very similar VS activity compared to pretest. In the CG, the VS activity was significantly attenuated.This longitudinal study revealed that video game training may preserve reward responsiveness in the ventral striatum in a retest situation over time. We suggest that video games are able to keep striatal responses to reward flexible, a mechanism which might be of critical value for applications such as therapeutic cognitive training.

  7. Changes in Incentives, Rewards and Sanctions.

    Science.gov (United States)

    Lonsdale, Alan

    1993-01-01

    A review of the literature over the past decade reflects substantial changes in rewards, incentives, and sanctions used with college faculty. These changes parallel changes in the public sector generally. Increasing emphasis on formal evaluation and on use of money as an incentive and reward for performance is noted. (MSE)

  8. Self-rewards and personal motivation

    NARCIS (Netherlands)

    Koch, A.K.; Nafziger, J.; Suvorov, A.; van de Ven, J.

    2014-01-01

    Self-administered rewards are ubiquitous. They serve as incentives for personal accomplishments and are widely recommended to increase personal motivation. We show that in a model with time-inconsistent and reference-dependent preferences, self-rewards can be a credible and effective tool to

  9. Reward modulates perception in binocular rivalry.

    Science.gov (United States)

    Marx, Svenja; Einhäuser, Wolfgang

    2015-01-14

    Our perception does not provide us with an exact imprint of the outside world, but is continuously adapted to our internal expectations, task sets, and behavioral goals. Although effects of reward-or value in general-on perception therefore seem likely, how valuation modulates perception and how such modulation relates to attention is largely unknown. We probed effects of reward on perception by using a binocular-rivalry paradigm. Distinct gratings drifting in opposite directions were presented to each observer's eyes. To objectify their subjective perceptual experience, the optokinetic nystagmus was used as measure of current perceptual dominance. In a first experiment, one of the percepts was either rewarded or attended. We found that reward and attention similarly biased perception. In a second experiment, observers performed an attentionally demanding task either on the rewarded stimulus, the other stimulus, or both. We found that-on top of an attentional effect on perception-at each level of attentional load, reward still modulated perception by increasing the dominance of the rewarded percept. Similarly, penalizing one percept increased dominance of the other at each level of attentional load. In turn, rewarding-and similarly nonpunishing-a percept yielded performance benefits that are typically associated with selective attention. In conclusion, our data show that value modulates perception in a similar way as the volitional deployment of attention, even though the relative effect of value is largely unaffected by an attention task. © 2015 ARVO.

  10. Performance-Based Rewards and Work Stress

    Science.gov (United States)

    Ganster, Daniel C.; Kiersch, Christa E.; Marsh, Rachel E.; Bowen, Angela

    2011-01-01

    Even though reward systems play a central role in the management of organizations, their impact on stress and the well-being of workers is not well understood. We review the literature linking performance-based reward systems to various indicators of employee stress and well-being. Well-controlled experiments in field settings suggest that certain…

  11. Monetary reward activates human prefrontal cortex

    International Nuclear Information System (INIS)

    Thut, G.; Roelcke, U.; Nienhusmeier, M.; Missimer, J.; Maguire, R.P.; Leenders, K.L.; Schultz, W.

    1997-01-01

    We present a rCBF PET activation study, in which we demonstrated that reward processing in humans activates a cortical-subcortical network including dorsolateral prefrontal, orbital frontal, thalamic and midbrain regions. It is suggested that, as found for non-human primates, the basal ganglia-thalamo-cortical system is implicated in reward processing. (author) 1 fig., 3 refs

  12. Self-rewards and personal motivation

    DEFF Research Database (Denmark)

    Koch, Alexander Karl; Nafziger, Julia; Suvorov, Anton

    2014-01-01

    Self-administered rewards are ubiquitous. They serve as incentives for personal accomplishments and are widely recommended to increase personal motivation. We show that in a model with time-inconsistent and reference-dependent preferences, self-rewards can be a credible and effective tool...

  13. Self-Rewards and Personal Motivation

    DEFF Research Database (Denmark)

    Koch, Alexander Karl; Nafziger, Julia; Suvorov, Anton

    Self-administered rewards are ubiquitous. They serve as incentives for personal accomplishments and are widely recommended to increase personal motivation. We show that in a model with time-inconsistent and reference-dependent preferences, self-rewards can be a credible and effective tool...

  14. 'Proactive' use of cue-context congruence for building reinforcement learning's reward function.

    Science.gov (United States)

    Zsuga, Judit; Biro, Klara; Tajti, Gabor; Szilasi, Magdolna Emma; Papp, Csaba; Juhasz, Bela; Gesztelyi, Rudolf

    2016-10-28

    Reinforcement learning is a fundamental form of learning that may be formalized using the Bellman equation. Accordingly an agent determines the state value as the sum of immediate reward and of the discounted value of future states. Thus the value of state is determined by agent related attributes (action set, policy, discount factor) and the agent's knowledge of the environment embodied by the reward function and hidden environmental factors given by the transition probability. The central objective of reinforcement learning is to solve these two functions outside the agent's control either using, or not using a model. In the present paper, using the proactive model of reinforcement learning we offer insight on how the brain creates simplified representations of the environment, and how these representations are organized to support the identification of relevant stimuli and action. Furthermore, we identify neurobiological correlates of our model by suggesting that the reward and policy functions, attributes of the Bellman equitation, are built by the orbitofrontal cortex (OFC) and the anterior cingulate cortex (ACC), respectively. Based on this we propose that the OFC assesses cue-context congruence to activate the most context frame. Furthermore given the bidirectional neuroanatomical link between the OFC and model-free structures, we suggest that model-based input is incorporated into the reward prediction error (RPE) signal, and conversely RPE signal may be used to update the reward-related information of context frames and the policy underlying action selection in the OFC and ACC, respectively. Furthermore clinical implications for cognitive behavioral interventions are discussed.

  15. A focus on reward in anorexia nervosa through the lens of the activity-based anorexia rodent model.

    Science.gov (United States)

    Foldi, C J; Milton, L K; Oldfield, B J

    2017-10-01

    Patients suffering anorexia nervosa (AN) become anhedonic, unable or unwilling to derive normal pleasures and tend to avoid rewarding outcomes, most profoundly in food intake. The activity-based anorexia model recapitulates many of the pathophysiological and behavioural hallmarks of the human condition, including a reduction in food intake, excessive exercise, dramatic weight loss, loss of reproductive cycles, hypothermia and anhedonia, and therefore it allows investigation into the underlying neurobiology of anorexia nervosa. The use of this model has directed attention to disruptions in central reward neurocircuitry, which may contribute to disease susceptibility. The purpose of this review is to demonstrate the utility of this unique model to provide insight into the mechanisms of reward relevant to feeding and weight loss, which may ultimately help to unravel the neurobiology of anorexia nervosa and, in a broader sense, the foundation of reward-based feeding. © 2017 British Society for Neuroendocrinology.

  16. The Dilemmas of Adopting Performance Related Pay as a Reward ...

    African Journals Online (AJOL)

    The Dilemmas of Adopting Performance Related Pay as a Reward Strategy for ... over automatic pay increase (formal and transparent reward systems linked to ... of reward and compensation, and low level of motivation and performance.

  17. Extending Markov Automata with State and Action Rewards

    NARCIS (Netherlands)

    Guck, Dennis; Timmer, Mark; Blom, Stefan; Bertrand, N.; Bortolussi, L.

    This presentation introduces the Markov Reward Automaton (MRA), an extension of the Markov automaton that allows the modelling of systems incorporating rewards in addition to nondeterminism, discrete probabilistic choice and continuous stochastic timing. Our models support both rewards that are

  18. Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats.

    Science.gov (United States)

    Johnson, Paul M; Kenny, Paul J

    2010-05-01

    We found that development of obesity was coupled with emergence of a progressively worsening deficit in neural reward responses. Similar changes in reward homeostasis induced by cocaine or heroin are considered to be crucial in triggering the transition from casual to compulsive drug-taking. Accordingly, we detected compulsive-like feeding behavior in obese but not lean rats, measured as palatable food consumption that was resistant to disruption by an aversive conditioned stimulus. Striatal dopamine D2 receptors (D2Rs) were downregulated in obese rats, as has been reported in humans addicted to drugs. Moreover, lentivirus-mediated knockdown of striatal D2Rs rapidly accelerated the development of addiction-like reward deficits and the onset of compulsive-like food seeking in rats with extended access to palatable high-fat food. These data demonstrate that overconsumption of palatable food triggers addiction-like neuroadaptive responses in brain reward circuits and drives the development of compulsive eating. Common hedonic mechanisms may therefore underlie obesity and drug addiction.

  19. Adolescent cannabinoid exposure effects on natural reward seeking and learning in rats.

    Science.gov (United States)

    Schoch, H; Huerta, M Y; Ruiz, C M; Farrell, M R; Jung, K M; Huang, J J; Campbell, R R; Piomelli, D; Mahler, S V

    2018-01-01

    Adolescence is characterized by endocannabinoid (ECB)-dependent refinement of neural circuits underlying emotion, learning, and motivation. As a result, adolescent cannabinoid receptor stimulation (ACRS) with phytocannabinoids or synthetic agonists like "Spice" cause robust and persistent changes in both behavior and circuit architecture in rodents, including in reward-related regions like medial prefrontal cortex and nucleus accumbens (NAc). Here, we examine persistent effects of ACRS with the cannabinoid receptor 1/2 specific agonist WIN55-212,2 (WIN; 1.2 mg/kg/day, postnatal day (PD) 30-43), on natural reward-seeking behaviors and ECB system function in adult male Long Evans rats (PD 60+). WIN ACRS increased palatable food intake, and altered attribution of incentive salience to food cues in a sign-/goal-tracking paradigm. ACRS also blunted hunger-induced sucrose intake, and resulted in increased anandamide and oleoylethanolamide levels in NAc after acute food restriction not seen in controls. ACRS did not affect food neophobia or locomotor response to a novel environment, but did increase preference for exploring a novel environment. These results demonstrate that ACRS causes long-term increases in natural reward-seeking behaviors and ECB system function that persist into adulthood, potentially increasing liability to excessive natural reward seeking later in life.

  20. Running on Empty: Leptin Signaling in VTA Regulates Reward from Physical Activity.

    Science.gov (United States)

    Chen, Zuxin; Kenny, Paul J

    2015-10-06

    Hunger increases physical activity and stamina to support food-directed foraging behaviors, but underlying mechanisms are unclear. In this issue, Fernandes et al. (2015) show that disruption of leptin-regulated STAT3 signaling in midbrain dopamine neurons increases the rewarding effects of running in mice, which could explain the "high" experienced by endurance runners. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Effect of Replacing Sugar with Non-Caloric Sweeteners in Beverages on the Reward Value after Repeated Exposure

    NARCIS (Netherlands)

    Griffioen-Roose, S.; Smeets, P.A.M.; Weijzen, P.L.G.; Rijn, van I.; Bosch, van den I.; Graaf, de C.

    2013-01-01

    Background: The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. Objective: To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty

  2. Dopamine and glucose, obesity and Reward Deficiency Syndrome

    Directory of Open Access Journals (Sweden)

    Kenneth eBlum

    2014-09-01

    Full Text Available Obesity and many well described eating disorders are accurately considered a global epidemic. The consequences of Reward Deficiency Syndrome, a genetic and epigenetic phenomena that involves the interactions of powerful neurotransmitters, are impairments of brain reward circuitry, hypodopaminergic function and abnormal craving behavior. Numerous sound neurochemical and genetic studies provide strong evidence that food addiction is similar to psychoactive drug addiction. Important facts which could translate to potential therapeutic targets espoused in this review include: 1 brain dopamine (DA production and use is stimulated by consumption of alcohol in large quantities or carbohydrates bingeing; 2 in the mesolimbic system the enkephalinergic neurons are in close proximity, to glucose receptors; 3 highly concentrated glucose activates the calcium channel to stimulate dopamine release from P12 cells; 4 blood glucose and cerebrospinal fluid concentrations of homovanillic acid, the dopamine metabolite, are significantly correlated and 5 2-deoxyglucose the glucose analogue, in pharmacological doses associates with enhanced dopamine turnover and causes acute glucoprivation. Evidence from animal studies and human fMRI support the hypothesis that multiple, but similar brain circuits are disrupted in obesity and drug dependence and DA-modulated reward circuits are involved in pathologic eating behaviors. Treatment for addiction to glucose and drugs alike, based on a consensus of neuroscience research, should incorporate dopamine agonist therapy, in contrast to current theories and practices that use dopamine antagonists. Until now, powerful dopamine-D2 agonists have failed clinically, due to chronic down regulation of D2 receptors instead, consideration of novel less powerful D2 agonists that up-regulate D2 receptors seems prudent. We encourage new strategies targeted at improving DA function in the treatment and prevention of obesity a subtype of

  3. A reward-centred model of anorexia nervosa: a focussed narrative review of the neurological and psychophysiological literature.

    Science.gov (United States)

    O'Hara, Caitlin B; Campbell, Iain C; Schmidt, Ulrike

    2015-05-01

    This focussed narrative review examines neurobiological and psychophysiological evidence supporting a role for altered reward processes in the development and maintenance of anorexia nervosa (AN). In AN, there does not appear to be a generalised inability to experience reward. Rather, data suggest that a reluctance to gain weight leads to an aversive appraisal of food- and taste-related stimuli. As a result, cues compatible with this aberrant mode of thinking become rewarding for the individual. Evidence also suggests that attribution of motivational salience to such cues promotes anorectic behaviours. These findings are consistent with models in which interactions between cognition and reward are important in eliciting the anorectic "habit". A model is proposed which is consistent with elements of other theoretical frameworks, but differs in that its emphasis is towards neural overlaps between AN and addiction. It is consistent with AN being a reward-based learned behaviour in which aberrant cognitions related to eating and shape alter functioning of central reward systems. It proposes that the primary neural problem responsible for the development, maintenance, and treatment resistance is centred in the striatal reward system. This helps shift the emphasis of aetiological models towards reward processing, particularly in the context of illness-compatible cues. Furthermore, it suggests that continuing to explore the utility and valued nature of AN in the patient's life would be a useful inclusion in treatment and prevention models. Copyright © 2015. Published by Elsevier Ltd.

  4. Rats prefer mutual rewards in a ProSocial Choice Task

    Directory of Open Access Journals (Sweden)

    Julen eHernandez-Lallement

    2015-01-01

    Full Text Available Pro-sociality, i.e. the preference for outcomes that produce benefits for other individuals, is ubiquitous in humans. Recently, cross-species comparisons of social behavior have offered important new insights into the evolution of pro-sociality. Here, we present a rodent analog of the Pro-social Choice Task that controls strategic components, de-confounds other-regarding choice motives from the animals’ natural tendencies to maximize own food access and directly tests the effect of social context on choice allocation. We trained pairs of rats – an actor and a partner rat – in a double T-maze task where actors decided between two alternatives only differing in the reward delivered to the partner. The own reward choice yielded a reward only accessible to the actor whereas the both reward choice produced an additional reward for a partner (partner condition or an inanimate toy (toy Condition, located in an adjacent compartment. We found that actors chose both reward at levels above chance and more often in the partner than in the toy condition. Moreover, we show that this choice pattern adapts to the current social context and that the observed behavior is stable over time.

  5. Curiosity and reward: Valence predicts choice and information prediction errors enhance learning.

    Science.gov (United States)

    Marvin, Caroline B; Shohamy, Daphna

    2016-03-01

    Curiosity drives many of our daily pursuits and interactions; yet, we know surprisingly little about how it works. Here, we harness an idea implied in many conceptualizations of curiosity: that information has value in and of itself. Reframing curiosity as the motivation to obtain reward-where the reward is information-allows one to leverage major advances in theoretical and computational mechanisms of reward-motivated learning. We provide new evidence supporting 2 predictions that emerge from this framework. First, we find an asymmetric effect of positive versus negative information, with positive information enhancing both curiosity and long-term memory for information. Second, we find that it is not the absolute value of information that drives learning but, rather, the gap between the reward expected and reward received, an "information prediction error." These results support the idea that information functions as a reward, much like money or food, guiding choices and driving learning in systematic ways. (c) 2016 APA, all rights reserved).

  6. Lipopolysaccharide reduces incentive motivation while boosting preference for high reward in mice.

    Science.gov (United States)

    Vichaya, Elisabeth G; Hunt, Sarah C; Dantzer, Robert

    2014-11-01

    Inflammation has been implicated in the development of various psychiatric disorders, including depression. However, the neurobehavioral mechanism involved in this relationship remains elusive. This gap in knowledge may best be filled by evaluating elementary neurobehavioral units affected by inflammation rather than behavioral changes in conventional animal tests of depression. To this end, the current study used a concurrent choice paradigm to evaluate inflammation-induced motivational changes. Male C57BL/6J mice (n=27) were food restricted to between 85 and 90% of their free-feeding weight and were trained to perform a concurrent choice task where they nose-poked for grain rewards on a fixed ratio (FR) 1 schedule (low effort/low reward) and chocolate-flavored rewards on a FR-10 schedule (high effort/high reward). A counterbalanced-within subjects design was used. A single intraperitoneal injection of 0.33 mg/kg lipopolysaccharide (LPS) was used to induce peripheral inflammation. Twenty-four hours after LPS administration, mice showed a reduction in the total number of nose pokes. A proportionally greater reduction in nose pokes was observed for grain, resulting in an increase in percent chocolate pellets earned. These behavioral changes cannot be explained by reduced appetite as feeding before the test led to a similar increase in percent chocolate pellets earned but without any decrease in responding. These results indicate that inflammation modulates incentive motivation by affecting willingness to exert effort for reward and not by reducing sensitivity to reward.

  7. Macaque monkeys can learn token values from human models through vicarious reward.

    Science.gov (United States)

    Bevacqua, Sara; Cerasti, Erika; Falcone, Rossella; Cervelloni, Milena; Brunamonti, Emiliano; Ferraina, Stefano; Genovesio, Aldo

    2013-01-01

    Monkeys can learn the symbolic meaning of tokens, and exchange them to get a reward. Monkeys can also learn the symbolic value of a token by observing conspecifics but it is not clear if they can learn passively by observing other actors, e.g., humans. To answer this question, we tested two monkeys in a token exchange paradigm in three experiments. Monkeys learned token values through observation of human models exchanging them. We used, after a phase of object familiarization, different sets of tokens. One token of each set was rewarded with a bit of apple. Other tokens had zero value (neutral tokens). Each token was presented only in one set. During the observation phase, monkeys watched the human model exchange tokens and watched them consume rewards (vicarious rewards). In the test phase, the monkeys were asked to exchange one of the tokens for food reward. Sets of three tokens were used in the first experiment and sets of two tokens were used in the second and third experiments. The valuable token was presented with different probabilities in the observation phase during the first and second experiments in which the monkeys exchanged the valuable token more frequently than any of the neutral tokens. The third experiments examined the effect of unequal probabilities. Our results support the view that monkeys can learn from non-conspecific actors through vicarious reward, even a symbolic task like the token-exchange task.

  8. Reward Inference by Primate Prefrontal and Striatal Neurons

    OpenAIRE

    Pan, Xiaochuan; Fan, Hongwei; Sawa, Kosuke; Tsuda, Ichiro; Tsukada, Minoru; Sakagami, Masamichi

    2014-01-01

    The brain contains multiple yet distinct systems involved in reward prediction. To understand the nature of these processes, we recorded single-unit activity from the lateral prefrontal cortex (LPFC) and the striatum in monkeys performing a reward inference task using an asymmetric reward schedule. We found that neurons both in the LPFC and in the striatum predicted reward values for stimuli that had been previously well experienced with set reward quantities in the asymmetric reward task. Im...

  9. Distinct Reward Properties are Encoded via Corticostriatal Interactions

    OpenAIRE

    David V. Smith; Anastasia E. Rigney; Mauricio R. Delgado

    2016-01-01

    The striatum serves as a critical brain region for reward processing. Yet, understanding the link between striatum and reward presents a challenge because rewards are composed of multiple properties. Notably, affective properties modulate emotion while informative properties help obtain future rewards. We approached this problem by emphasizing affective and informative reward properties within two independent guessing games. We found that both reward properties evoked activation within the nu...

  10. Touch massage, a rewarding experience.

    Science.gov (United States)

    Lindgren, Lenita; Jacobsson, Maritha; Lämås, Kristina

    2014-12-01

    This study aims to describe and analyze healthy individuals' expressed experiences of touch massage (TM). Fifteen healthy participants received whole body touch massage during 60 minutes for two separate occasions. Interviews were analyzed by narrative analysis. Four identifiable storyline was found, Touch massage as an essential need, in this storyline the participants talked about a desire and need for human touch and TM. Another storyline was about, Touch massage as a pleasurable experience and the participants talked about the pleasure of having had TM. In the third storyline Touch massage as a dynamic experience, the informants talked about things that could modulate the experience of receiving TM. In the last storyline, Touch massage influences self-awareness, the participants described how TM affected some of their psychological and physical experiences. Experiences of touch massage was in general described as pleasant sensations and the different storylines could be seen in the light of rewarding experiences. © The Author(s) 2014.

  11. International ROR: risk, opportunity, reward

    International Nuclear Information System (INIS)

    Krentz, D.; Gair, J.

    1996-01-01

    Norcen Energy Resources Limited's pursuit of international oil and gas opportunities since the late 1980s were outlined. By 1994 Norcen had exploration and production concessions in 12 countries stretching from Algeria, Russia, Argentina, Indonesia to offshore Australia. The company had seen its share of risks, opportunities and rewards. Since 1994 international efforts of the Company have been focused on lower risk opportunities with exploration upside in defined core areas of South America, particularly in Venezuela, a country with conventional, heavy and ultra-heavy oil resources exceeding that of Saudi Arabia. These, and other similar foreign investments in the formerly closed national oil industries of South America have been greatly facilitated by the political liberalization, economic reforms and stabilization that have taken place there over the past ten years. The story of Norcen's successful bidding on the Oritupano-Leona production block in 1993 and Delta Centro exploration block in 1996 was the subject of this presentation

  12. Floral reward in Ranunculaceae species

    Directory of Open Access Journals (Sweden)

    Bożena Denisow

    2016-04-01

    Full Text Available Floral reward is important in ecological and evolutionary perspectives and essential in pollination biology. For example, floral traits, nectar and pollen features are essential for understanding the functional ecology, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant–pollinator interactions. We believe to present a synthetic description in the field of floral reward in Ranunculaceae family important in pollination biology and indicating connections between ecological and evolutionary approaches. The links between insect visitors’ behaviour and floral reward type and characteristics exist. Ranunculaceae is a family of aboot 1700 species (aboot 60 genera, distributed worldwide, however the most abundant representatives are in temperate and cool regions of the northern and southern hemispheres. The flowers are usually radially symmetric (zygomorphic and bisexual, but in Aconitum, Aquilegia are bilaterally symmetric (zygomorphic. Most Ranunculaceae flowers offer no nectar, only pollen (e.g., Ranunculus, Adonis vernalis, Thalictrum, but numerous species create trophic niches for different wild pollinators (e.g. Osmia, Megachile, Bombus, Andrena (Denisow et al. 2008. Pollen is a source of protein, vitamins, mineral salts, organic acids and hormones, but the nutritional value varies greatly between different plant species. The pollen production can differ significantly between Ranunculacea species. The mass of pollen produced in anthers differ due to variations in the number of developed anthers. For example, interspecies differences are considerable, 49 anthers are noted in Aquilegia vulgaris, 70 anthers in Ranunculus lanuginosus, 120 in Adonis vernalis. A significant intra-species differences’ in the number of anthers are also noted (e.g. 41 to 61 in Aquilegia vulgaris, 23-45 in Ranunculus cassubicus. Pollen production can be up to 62 kg per ha for Ranunculus acer

  13. An Animal Model of Genetic Vulnerability to Behavioral Disinhibition and Responsiveness to Reward-Related Cues: Implications for Addiction

    OpenAIRE

    Flagel, Shelly B; Robinson, Terry E; Clark, Jeremy J; Clinton, Sarah M; Watson, Stanley J; Seeman, Phillip; Phillips, Paul E M; Akil, Huda

    2009-01-01

    Rats selectively bred based on high or low reactivity to a novel environment were characterized for other behavioral and neurobiological traits thought to be relevant to addiction vulnerability. The two lines of animals, which differ in their propensity to self-administer drugs, also differ in the value they attribute to cues associated with reward, in impulsive behavior, and in their dopamine system. When a cue was paired with food or cocaine reward bred high-responder rats (bHRs) learned to...

  14. High temporal discounters overvalue immediate rewards rather than undervalue future rewards: an event-related brain potential study.

    Science.gov (United States)

    Cherniawsky, Avital S; Holroyd, Clay B

    2013-03-01

    Impulsivity is characterized in part by heightened sensitivity to immediate relative to future rewards. Although previous research has suggested that "high discounters" in intertemporal choice tasks tend to prefer immediate over future rewards because they devalue the latter, it remains possible that they instead overvalue immediate rewards. To investigate this question, we recorded the reward positivity, a component of the event-related brain potential (ERP) associated with reward processing, with participants engaged in a task in which they received both immediate and future rewards and nonrewards. The participants also completed a temporal discounting task without ERP recording. We found that immediate but not future rewards elicited the reward positivity. High discounters also produced larger reward positivities to immediate rewards than did low discounters, indicating that high discounters relatively overvalued immediate rewards. These findings suggest that high discounters may be more motivated than low discounters to work for monetary rewards, irrespective of the time of arrival of the incentives.

  15. Hidden hunger or knowledge hunger? Nutritional knowledge, diet diversity and micronutrient intake in Rwanda: The case of Vitamin A

    OpenAIRE

    Okello, Julius J.; Sindi, Kirimi; Low, Jan; Shikuku, Kelvin M.

    2013-01-01

    The problem of hidden hunger has emerged as one of the major development issues alongside food security. This problem highlights the likelihood of households having access to inadequate amount of key micronutrients in a diet despite having access to adequate quantities of food. , This paper uses a recent detailed household consumption data to investigate households’ nutritional knowledge, the diversity of diets consumed, and the micronutrient uptake, focusing specifically on Vitamin A. The st...

  16. Chimpanzees' socially maintained food preferences indicate both conservatism and conformity

    DEFF Research Database (Denmark)

    Hopper, LM; Schapiro, Steve; Lambeth, SP

    2011-01-01

    . This study provides the first evidence that chimpanzees show such conservatism even when the new method employs the identical required behaviour as the first, but for a different reward. Groups of chimpanzees could choose to exchange one of two types of inedible tokens, with each token type being associated...... with a different food reward: one type was rewarded with a highly preferred food (grape) and the other type was rewarded with a less preferred food (carrot). Individuals first observed a model chimpanzee from their social group trained to choose one of the two types of tokens. In one group, this token earned...... a carrot, while in the other, control, group the token earned a grape. In both groups, chimpanzees conformed to the trained model’s choice. This was especially striking for those gaining the pieces of carrot, the less favoured reward. This resulted in a population-level trend of food choices, even when...

  17. The role of intrinsic and extrinsic rewards in committing violence during combat: A cross-sectional study with former combatants in the DR Congo.

    Science.gov (United States)

    Haer, Roos; Hermenau, Katharin; Elbert, Thomas; Moran, James K; Hecker, Tobias

    2017-05-01

    It has been postulated that the violent behavior that characterizes armed conflict is reinforced by the possibility of receiving rewards. The present study examined the potential influence of two types of rewards in an ongoing setting of conflict: extrinsic and intrinsic rewards. Former combatants active in the Democratic Republic of the Congo (N = 198) were interviewed and questioned about the way they were recruited, the offenses they committed during combat, their level of perceived intrinsic rewards (i.e., appetitive perception of violence), and the number of received extrinsic rewards during their time in the armed group (e.g., money, extra food, alcohol, or drugs). A moderated multiple regression analysis showed that the number of received extrinsic rewards and the level of intrinsic rewards were significantly positively related to the number of different types of offenses committed. In contrast to our expectations and previous findings, the recruitment type (forced conscription vs. voluntary enlistment) did not moderate this relation. Our findings suggest that both types of rewards play a role in committing violence during combat. We suggest, therefore, that reintegration programs should not only consider the influence of extrinsic rewards, but also need to address the influence of intrinsic rewards to counter violent behavior among former combatants. Aggr. Behav. 43:241-250, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Managing Food Allergies in School.

    Science.gov (United States)

    Munoz-Furlong, Anne

    1997-01-01

    The number of students with food allergies is increasing, with peanuts the leading culprit. Peer pressure and allergens hidden in baked goods can pose problems for school staff. Children with documented life-threatening allergies are covered by the Americans with Disabilities Act. Principals should reassure parents and use Section 504 guidelines…

  19. Slave to habit? Obesity is associated with decreased behavioural sensitivity to reward devaluation.

    Science.gov (United States)

    Horstmann, Annette; Dietrich, Anja; Mathar, David; Pössel, Maria; Villringer, Arno; Neumann, Jane

    2015-04-01

    The motivational value of food is lower during satiety compared to fasting. Dynamic changes in motivational value promote food seeking or meal cessation. In obesity this mechanism might be compromised since obese subjects ingest energy beyond homeostatic needs. Thus, lower adaptation of eating behaviour with respect to changes in motivational value might cause food overconsumption in obesity. To test this hypothesis, we implemented a selective satiation procedure to investigate the relationship between obesity and the size of the behavioural devaluation effect in humans. Lean to obese men (mean age 25.9, range 19-30 years; mean BMI 29.1, range 19.2-45.1 kg/m(2)) were trained on a free operant paradigm and learned to associate cues with the possibility to win different food rewards by pressing a button. After the initial training phase, one of the rewards was devalued by consumption. Response rates for and wanting of the different rewards were measured pre and post devaluation. Behavioural sensitivity to reward devaluation, measured as the magnitude of difference between pre and post responses, was regressed against BMI. Results indicate that (1) higher BMI compared to lower BMI in men led to an attenuated behavioural adjustment to reward devaluation, and (2) the decrease in motivational value was associated with the decrease in response rate between pre and post. Change in explicitly reported motivational value, however, was not affected by BMI. Thus, we conclude that high BMI in men is associated with lower behavioural adaptation with respect to changes in motivational value of food, possibly resulting in automatic overeating patterns that are hard to control in daily life. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Neuroendocrinology and brain imaging of reward in eating disorders: A possible key to the treatment of anorexia nervosa and bulimia nervosa.

    Science.gov (United States)

    Monteleone, Alessio Maria; Castellini, Giovanni; Volpe, Umberto; Ricca, Valdo; Lelli, Lorenzo; Monteleone, Palmiero; Maj, Mario

    2018-01-03

    Anorexia nervosa and bulimia nervosa are severe eating disorders whose etiopathogenesis is still unknown. Clinical features suggest that eating disorders may develop as reward-dependent syndromes, since eating less food is perceived as rewarding in anorexia nervosa while consumption of large amounts of food during binge episodes in bulimia nervosa aims at reducing the patient's negative emotional states. Therefore, brain reward mechanisms have been a major focus of research in the attempt to contribute to the comprehension of the pathophysiology of these disorders. Structural brain imaging data provided the evidence that brain reward circuits may be altered in patients with anorexia or bulimia nervosa. Similarly, functional brain imaging studies exploring the activation of brain reward circuits by food stimuli as well as by stimuli recognized to be potentially rewarding for eating disordered patients, such as body image cues or stimuli related to food deprivation and physical hyperactivity, showed several dysfunctions in ED patients. Moreover, very recently, it has been demonstrated that some of the biochemical homeostatic modulators of eating behavior are also implicated in the regulation of food-related and non-food-related reward, representing a possible link between the aberrant behaviors of ED subjects and their hypothesized deranged reward processes. In particular, changes in leptin and ghrelin occur in patients with anorexia or bulimia nervosa and have been suggested to represent not only homeostatic adaptations to an altered energy balance but to contribute also to the acquisition and/or maintenance of persistent starvation, binge eating and physical hyperactivity, which are potentially rewarding for ED patients. On the basis of such findings new pathogenetic models of EDs have been proposed, and these models may provide new theoretical basis for the development of innovative treatment strategies, either psychological and pharmacological, with the aim to

  1. Gut peptide GLP-1 and its analogue, Exendin-4, decrease alcohol intake and reward.

    Directory of Open Access Journals (Sweden)

    Rozita H Shirazi

    Full Text Available Glucagon-like-peptide-1 (GLP-1 is a gut- and neuro-peptide with an important role in the regulation of food intake and glucose metabolism. Interestingly, GLP-1 receptors (GLP-1R are expressed in key mesolimbic reward areas (including the ventral tegmental area, VTA, innervated by hindbrain GLP-1 neurons. Recently GLP-1 has emerged as a potential regulator of food reward behavior, an effect driven by the mesolimbic GLP-1Rs. Its role in other reward behaviors remains largely unexplored. Since a considerable overlap has been suggested for circuitry controlling reward behavior derived from food and alcohol we hypothesized that GLP-1 and GLP-1Rs could regulate alcohol intake and alcohol reward. We sought to determine whether GLP-1 or its clinically safe stable analogue, Exendin-4, reduce alcohol intake and reward. To determine the potential role of the endogenous GLP-1 in alcohol intake we evaluated whether GLP-1R antagonist, Exendin 9-39, can increase alcohol intake. Furthermore, we set out to evaluate whether VTA GLP-1R activation is sufficient to reduce alcohol intake. Male Wistar rats injected peripherally with GLP-1 or Exendin-4 reduced their alcohol intake in an intermittent access two bottle free choice drinking model. Importantly, a contribution of endogenously released GLP-1 is highlighted by our observation that blockade of GLP-1 receptors alone resulted in an increased alcohol intake. Furthermore, GLP-1 injection reduced alcohol reward in the alcohol conditioned place preference test in mice. To evaluate the neuroanatomical substrate linking GLP-1 with alcohol intake/reward, we selectively microinjected GLP-1 or Exendin 4 into the VTA. This direct stimulation of the VTA GLP-1 receptors potently reduced alcohol intake. Our findings implicate GLP-1R signaling as a novel modulator of alcohol intake and reward. We show for the first time that VTA GLP-1R stimulation leads to reduced alcohol intake. Considering that GLP-1 analogues are already

  2. Rewards and advancements for clinical pharmacists.

    Science.gov (United States)

    Goodwin, S Diane; Kane-Gill, Sandra L; Ng, Tien M H; Melroy, Joel T; Hess, Mary M; Tallian, Kimberly; Trujillo, Toby C; Vermeulen, Lee C

    2010-01-01

    The American College of Clinical Pharmacy charged the Clinical Practice Affairs Committee to review and update the College's 1995 White Paper, "Rewards and Advancements for Clinical Pharmacy Practitioners." Because of the limited data on the present state of rewards and advancements for clinical pharmacists, an online survey of "front-line" clinical pharmacists and pharmacy managers was conducted (1126 total respondents, 14% response rate). The resulting White Paper discusses motivators and existing systems of rewards and advancements for clinical pharmacists, as well as perceived barriers to implementation of these systems. Clinical pharmacists reported work-life balance, a challenging position, and opportunities for professional advancement as the most important factors for career success. At the time of the survey, financial rewards appeared not to be a major motivator for clinical pharmacists. Managers underestimated the importance that clinical pharmacists place on work-life balance and favorable work schedules. Although almost two thirds of the clinical pharmacists surveyed had not developed a professional development plan, 84% indicated an interest in career planning. Both clinical pharmacists and managers rated the lack of a clear reward and advancement structure as the most important barrier to effective systems of rewards and advancements. Pharmacy managers and administrators are encouraged to develop effective systems of rewards and advancements for clinical pharmacists that positively impact patient care and the institution's mission; these systems will benefit the clinical pharmacist, the health care institution, and the patient.

  3. Prosocial reward learning in children and adolescents

    Directory of Open Access Journals (Sweden)

    Youngbin Kwak

    2016-10-01

    Full Text Available Adolescence is a period of increased sensitivity to social contexts. To evaluate how social context sensitivity changes over development – and influences reward learning – we investigated how children and adolescents perceive and integrate rewards for oneself and others during a dynamic risky-decision-making task. Children and adolescents (N=75, 8-16 yrs performed the Social Gambling Task (SGT, (Kwak et al., 2014 and completed a set of questionnaires measuring other-regarding behavior. In the SGT, participants choose amongst four card decks that have different payout structures for oneself and for a charity. We examined patterns of choices, overall decision strategies, and how reward outcomes led to trial-by-trial adjustments in behavior, as estimated using a reinforcement-learning model. Performance of children and adolescents was compared to data from a previously collected sample of adults (N=102 performing the identical task. We found that that children/adolescents were not only more sensitive to rewards directed to the charity than self but also showed greater prosocial tendencies on independent measures of other-regarding behavior. Children and adolescents also showed less use of a strategy that prioritizes rewards for self at the expense of rewards for others. These results support the conclusion that, compared to adults, children and adolescents show greater sensitivity to outcomes for others when making decisions and learning about potential rewards.

  4. Incidental rewarding cues influence economic decisions in people with obesity

    Science.gov (United States)

    Simmank, Jakob; Murawski, Carsten; Bode, Stefan; Horstmann, Annette

    2015-01-01

    Recent research suggests that obesity is linked to prominent alterations in learning and decision-making. This general difference may also underlie the preference for immediately consumable, highly palatable but unhealthy and high-calorie foods. Such poor food-related inter-temporal decision-making can explain weight gain; however, it is not yet clear whether this deficit can be generalized to other domains of inter-temporal decision-making, for example financial decisions. Further, little is known about the stability of decision-making behavior in obesity, especially in the presence of rewarding cues. To answer these questions, obese and lean participants (n = 52) completed two sessions of a novel priming paradigm including a computerized monetary delay discounting task. In the first session, general differences between groups in financial delay discounting were measured. In the second session, we tested the general stability of discount rates. Additionally, participants were primed by affective visual cues of different contextual categories before making financial decisions. We found that the obese group showed stronger discounting of future monetary rewards than the lean group, but groups did not differ in their general stability between sessions nor in their sensitivity toward changes in reward magnitude. In the obese group, a fast decrease of subjective value over time was directly related to a higher tendency for opportunistic eating. Obese in contrast to lean people were primed by the affective cues, showing a sex-specific pattern of priming direction. Our findings demonstrate that environments rich of cues, aiming at inducing unhealthy consumer decisions, can be highly detrimental for obese people. It also underscores that obesity is not merely a medical condition but has a strong cognitive component, meaning that current dietary and medical treatment strategies may fall too short. PMID:26528158

  5. Incidental rewarding cues influence economic decision-making in obesity

    Directory of Open Access Journals (Sweden)

    Jakob eSimmank

    2015-10-01

    Full Text Available Recent research suggests that obesity is linked to prominent alterations in learning and decision-making. This general difference may also underlie the preference for immediately consumable, highly palatable but unhealthy and high-calorie foods. Such poor food-related inter-temporal decision-making can explain weight gain; however, it is not yet clear whether this deficit can be generalized to other domains of inter-temporal decision-making, for example financial decisions. Further, little is known about the stability of decision-making behavior in obesity, especially in the presence of rewarding cues. To answer these questions, obese and lean participants (n=52 completed two sessions of a novel priming paradigm including a computerized monetary delay discounting task. In the first session, general differences between groups in financial delay discounting were measured. In the second session, we tested the general stability of discounting rates. Additionally, participants were primed by affective visual cues of different contextual categories before the financial decision. We found that the obese group showed stronger discounting of future monetary rewards than the lean group, but groups did not differ in their general stability between sessions nor in their sensitivity towards changes in reward magnitude. In the obese group, a fast decrease of subjective value over time was directly related to a higher tendency for opportunistic eating. Obese in contrast to lean people were primed by the affective cues, showing a sex-specific pattern of priming direction. Our findings demonstrate that environments rich of cues, aiming at inducing unhealthy consumer decisions, can be highly detrimental for obese people. It also underscores that obesity is not merely a medical condition but has a strong cognitive component, meaning that current dietary and medical treatment strategies may fall too short.

  6. Abnormal Striatal BOLD Responses to Reward Anticipation and Reward Delivery in ADHD

    Science.gov (United States)

    Furukawa, Emi; Bado, Patricia; Tripp, Gail; Mattos, Paulo; Wickens, Jeff R.; Bramati, Ivanei E.; Alsop, Brent; Ferreira, Fernanda Meireles; Lima, Debora; Tovar-Moll, Fernanda; Sergeant, Joseph A.; Moll, Jorge

    2014-01-01

    Altered reward processing has been proposed to contribute to the symptoms of attention deficit hyperactivity disorder (ADHD). The neurobiological mechanism underlying this alteration remains unclear. We hypothesize that the transfer of dopamine release from reward to reward-predicting cues, as normally observed in animal studies, may be deficient in ADHD. Functional magnetic resonance imaging (fMRI) was used to investigate striatal responses to reward-predicting cues and reward delivery in a classical conditioning paradigm. Data from 14 high-functioning and stimulant-naïve young adults with elevated lifetime symptoms of ADHD (8 males, 6 females) and 15 well-matched controls (8 males, 7 females) were included in the analyses. During reward anticipation, increased blood-oxygen-level-dependent (BOLD) responses in the right ventral and left dorsal striatum were observed in controls, but not in the ADHD group. The opposite pattern was observed in response to reward delivery; the ADHD group demonstrated significantly greater BOLD responses in the ventral striatum bilaterally and the left dorsal striatum relative to controls. In the ADHD group, the number of current hyperactivity/impulsivity symptoms was inversely related to ventral striatal responses during reward anticipation and positively associated with responses to reward. The BOLD response patterns observed in the striatum are consistent with impaired predictive dopamine signaling in ADHD, which may explain altered reward-contingent behaviors and symptoms of ADHD. PMID:24586543

  7. Adaptive neural reward processing during anticipation and receipt of monetary rewards in mindfulness meditators.

    Science.gov (United States)

    Kirk, Ulrich; Brown, Kirk Warren; Downar, Jonathan

    2015-05-01

    Reward seeking is ubiquitous and adaptive in humans. But excessive reward seeking behavior, such as chasing monetary rewards, may lead to diminished subjective well-being. This study examined whether individuals trained in mindfulness meditation show neural evidence of lower susceptibility to monetary rewards. Seventy-eight participants (34 meditators, 44 matched controls) completed the monetary incentive delay task while undergoing functional magnetic resonance imaging. The groups performed equally on the task, but meditators showed lower neural activations in the caudate nucleus during reward anticipation, and elevated bilateral posterior insula activation during reward anticipation. Meditators also evidenced reduced activations in the ventromedial prefrontal cortex during reward receipt compared with controls. Connectivity parameters between the right caudate and bilateral anterior insula were attenuated in meditators during incentive anticipation. In summary, brain regions involved in reward processing-both during reward anticipation and receipt of reward-responded differently in mindfulness meditators than in nonmeditators, indicating that the former are less susceptible to monetary incentives. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  8. Reward loss and the basolateral amygdala: A function in reward comparisons.

    Science.gov (United States)

    Kawasaki, Katsuyoshi; Annicchiarico, Iván; Glueck, Amanda C; Morón, Ignacio; Papini, Mauricio R

    2017-07-28

    The neural circuitry underlying behavior in reward loss situations is poorly understood. We considered two such situations: reward devaluation (from large to small rewards) and reward omission (from large rewards to no rewards). There is evidence that the central nucleus of the amygdala (CeA) plays a role in the negative emotion accompanying reward loss. However, little is known about the function of the basolateral nucleus (BLA) in reward loss. Two hypotheses of BLA function in reward loss, negative emotion and reward comparisons, were tested in an experiment involving pretraining excitotoxic BLA lesions followed by training in four tasks: consummatory successive negative contrast (cSNC), autoshaping (AS) acquisition and extinction, anticipatory negative contrast (ANC), and open field testing (OF). Cell counts in the BLA (but not in the CeA) were significantly lower in animals with lesions vs. shams. BLA lesions eliminated cSNC and ANC, and accelerated extinction of lever pressing in AS. BLA lesions had no effect on OF testing: higher activity in the periphery than in the central area. This pattern of results provides support for the hypothesis that BLA neurons are important for reward comparison. The three affected tasks (cSNC, ANC, and AS extinction) involve reward comparisons. However, ANC does not seem to involve negative emotions and it was affected, whereas OF activity is known to involve negative emotion, but it was not affected. It is hypothesized that a circuit involving the thalamus, insular cortex, and BLA is critically involved in the mechanism comparing current and expected rewards. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Extended abstract of a hidden agenda

    Energy Technology Data Exchange (ETDEWEB)

    Goguen, J.; Malcolm, G. [Oxford Univ. (United Kingdom)

    1996-12-31

    The initial goal of our hidden research programme was both straightforward and ambitious: give a semantics for software engineering, and in particular for the object paradigm, supporting correctness proofs that are as simple and mechanical as possible. This emphasizes proofs rather than models, and thus suggests an equational approach, rather than one based on higher order logic, denotational semantics, or any kind of model, because equational proofs achieve maximal simplicity and mechanization, and yet are fully expressive. We introduce powerful coinduction techniques for proving behavioral properties of complex systems. We make the no doubt outrageous claim that our hidden approach gives simpler proofs than other formalisms; this is because we exploit algebraic structure that most other approaches discard.

  10. Laser experiments explore the hidden sector

    International Nuclear Information System (INIS)

    Ahlers, M.

    2007-11-01

    Recently, the laser experiments BMV and GammeV, searching for light shining through walls, have published data and calculated new limits on the allowed masses and couplings for axion-like particles. In this note we point out that these experiments can serve to constrain a much wider variety of hidden-sector particles such as, e.g., minicharged particles and hidden-sector photons. The new experiments improve the existing bounds from the older BFRT experiment by a factor of two. Moreover, we use the new PVLAS constraints on a possible rotation and ellipticity of light after it has passed through a strong magnetic field to constrain pure minicharged particle models. For masses -7 times the electron electric charge. This is the best laboratory bound and comparable to bounds inferred from the energy spectrum of the cosmic microwave background. (orig.)

  11. Quantum mechanics and hidden superconformal symmetry

    Science.gov (United States)

    Bonezzi, R.; Corradini, O.; Latini, E.; Waldron, A.

    2017-12-01

    Solvability of the ubiquitous quantum harmonic oscillator relies on a spectrum generating osp (1 |2 ) superconformal symmetry. We study the problem of constructing all quantum mechanical models with a hidden osp (1 |2 ) symmetry on a given space of states. This problem stems from interacting higher spin models coupled to gravity. In one dimension, we show that the solution to this problem is the Vasiliev-Plyushchay family of quantum mechanical models with hidden superconformal symmetry obtained by viewing the harmonic oscillator as a one dimensional Dirac system, so that Grassmann parity equals wave function parity. These models—both oscillator and particlelike—realize all possible unitary irreducible representations of osp (1 |2 ).

  12. Hidden Costs and the Role of Modularity

    DEFF Research Database (Denmark)

    Larsen, Marcus M.

    2013-01-01

    that the inability to effectively estimate the costs of implementing an activity in a foreign location has a negative impact on the process performance of that activity. Performance is deterred as operations are likely to be disrupted by opportunity costs and managerial responses. However, this relationship......This paper addresses estimation errors in strategic decision-making processes due to hidden costs. While previous research has investigated the antecedents of hidden costs, this paper investigates performance consequences. Using unique data on 221 offshoring implementations, it is argued...... is mitigated by the degree of modularity in the activity as it reduces the need for costly coordination in offshoring. This paper contributes to research on offshoring and strategic decision-making by emphasizing the importance of organizational design and of estimating the costs of internal organizational...

  13. Reward and Attentional Control in Visual Search

    Science.gov (United States)

    Anderson, Brian A.; Wampler, Emma K.; Laurent, Patryk A.

    2015-01-01

    It has long been known that the control of attention in visual search depends both on voluntary, top-down deployment according to context-specific goals, and on involuntary, stimulus-driven capture based on the physical conspicuity of perceptual objects. Recent evidence suggests that pairing target stimuli with reward can modulate the voluntary deployment of attention, but there is little evidence that reward modulates the involuntary deployment of attention to task-irrelevant distractors. We report several experiments that investigate the role of reward learning on attentional control. Each experiment involved a training phase and a test phase. In the training phase, different colors were associated with different amounts of monetary reward. In the test phase, color was not task-relevant and participants searched for a shape singleton; in most experiments no reward was delivered in the test phase. We first show that attentional capture by physically salient distractors is magnified by a previous association with reward. In subsequent experiments we demonstrate that physically inconspicuous stimuli previously associated with reward capture attention persistently during extinction—even several days after training. Furthermore, vulnerability to attentional capture by high-value stimuli is negatively correlated across individuals with working memory capacity and positively correlated with trait impulsivity. An analysis of intertrial effects reveals that value-driven attentional capture is spatially specific. Finally, when reward is delivered at test contingent on the task-relevant shape feature, recent reward history modulates value-driven attentional capture by the irrelevant color feature. The influence of learned value on attention may provide a useful model of clinical syndromes characterized by similar failures of cognitive control, including addiction, attention-deficit/hyperactivity disorder, and obesity. PMID:23437631

  14. Reward-dependent modulation of movement variability.

    Science.gov (United States)

    Pekny, Sarah E; Izawa, Jun; Shadmehr, Reza

    2015-03-04

    Movement variability is often considered an unwanted byproduct of a noisy nervous system. However, variability can signal a form of implicit exploration, indicating that the nervous system is intentionally varying the motor commands in search of actions that yield the greatest success. Here, we investigated the role of the human basal ganglia in controlling reward-dependent motor variability as measured by trial-to-trial changes in performance during a reaching task. We designed an experiment in which the only performance feedback was success or failure and quantified how reach variability was modulated as a function of the probability of reward. In healthy controls, reach variability increased as the probability of reward decreased. Control of variability depended on the history of past rewards, with the largest trial-to-trial changes occurring immediately after an unrewarded trial. In contrast, in participants with Parkinson's disease, a known example of basal ganglia dysfunction, reward was a poor modulator of variability; that is, the patients showed an impaired ability to increase variability in response to decreases in the probability of reward. This was despite the fact that, after rewarded trials, reach variability in the patients was comparable to healthy controls. In summary, we found that movement variability is partially a form of exploration driven by the recent history of rewards. When the function of the human basal ganglia is compromised, the reward-dependent control of movement variability is impaired, particularly affecting the ability to increase variability after unsuccessful outcomes. Copyright © 2015 the authors 0270-6474/15/354015-10$15.00/0.

  15. The Hidden Gifts of Quiet Kids

    Science.gov (United States)

    Trierweiler, Hannah

    2006-01-01

    The author relates that she was an introvert child. It has always taken her time and energy to find her place in a group. As a grown-up, she still needed quiet time to regroup during a busy day. In this article, the author presents an interview with Marti Olsen Laney, author of "The Hidden Gifts of the Introverted Child." During the interview,…

  16. Hidden neuronal correlations in cultured networks

    International Nuclear Information System (INIS)

    Segev, Ronen; Baruchi, Itay; Hulata, Eyal; Ben-Jacob, Eshel

    2004-01-01

    Utilization of a clustering algorithm on neuronal spatiotemporal correlation matrices recorded during a spontaneous activity of in vitro networks revealed the existence of hidden correlations: the sequence of synchronized bursting events (SBEs) is composed of statistically distinguishable subgroups each with its own distinct pattern of interneuron spatiotemporal correlations. These findings hint that each of the SBE subgroups can serve as a template for coding, storage, and retrieval of a specific information

  17. A masking index for quantifying hidden glitches

    OpenAIRE

    Berti-Equille, Laure; Loh, J. M.; Dasu, T.

    2015-01-01

    Data glitches are errors in a dataset. They are complex entities that often span multiple attributes and records. When they co-occur in data, the presence of one type of glitch can hinder the detection of another type of glitch. This phenomenon is called masking. In this paper, we define two important types of masking and propose a novel, statistically rigorous indicator called masking index for quantifying the hidden glitches. We outline four cases of masking: outliers masked by missing valu...

  18. Cold dark matter from the hidden sector

    International Nuclear Information System (INIS)

    Arias, Paola; Pontificia Univ. Catolica de Chile, Santiago

    2012-02-01

    Weakly interacting slim particles (WISPs) such as hidden photons (HP) and axion-like particles (ALPs) have been proposed as cold dark matter candidates. They might be produced non-thermally via the misalignment mechanism, similarly to cold axions. In this talk we review the main processes of thermalisation of HP and we compute the parameter space that may survive as cold dark matter population until today. Our findings are quite encouraging for experimental searches in the laboratory in the near future.

  19. Completing Quantum Mechanics with Quantized Hidden Variables

    OpenAIRE

    van Enk, S. J.

    2015-01-01

    I explore the possibility that a quantum system S may be described completely by the combination of its standard quantum state $|\\psi\\rangle$ and a (hidden) quantum state $|\\phi\\rangle$ (that lives in the same Hilbert space), such that the outcome of any standard projective measurement on the system S is determined once the two quantum states are specified. I construct an algorithm that retrieves the standard quantum-mechanical probabilities, which depend only on $|\\psi\\rangle$, by assuming t...

  20. Cold dark matter from the hidden sector

    Energy Technology Data Exchange (ETDEWEB)

    Arias, Paola [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pontificia Univ. Catolica de Chile, Santiago (Chile). Facultad de Fisica

    2012-02-15

    Weakly interacting slim particles (WISPs) such as hidden photons (HP) and axion-like particles (ALPs) have been proposed as cold dark matter candidates. They might be produced non-thermally via the misalignment mechanism, similarly to cold axions. In this talk we review the main processes of thermalisation of HP and we compute the parameter space that may survive as cold dark matter population until today. Our findings are quite encouraging for experimental searches in the laboratory in the near future.

  1. Hidden histories: challenges for pedagogy and participation

    OpenAIRE

    Morrice, Linda

    2013-01-01

    Higher Education has become and an increasingly diverse and globalised system in which the binaries between ‘traditional’ and ‘non-traditional’ students, exclusion and inclusion have less resonance and analytical purchase. Drawing on research with refugees Linda will suggest that higher education can be marked simultaneously by belonging and recognition, deficit and exclusion. Complex differences and inequalities remain hidden and unspoken, raising new questions and challenges for pedagogy an...

  2. Long-term memory of relative reward values.

    Science.gov (United States)

    Soldati, Francesca; Burman, Oliver H P; John, Elizabeth A; Pike, Thomas W; Wilkinson, Anna

    2017-02-01

    Long-term memory can be adaptive as it allows animals to retain information that is crucial for survival, such as the appearance and location of key resources. This is generally examined by comparing choices of stimuli that have value to the animal with those that do not; however, in nature choices are rarely so clear cut. Animals are able to assess the relative value of a resource via direct comparison, but it remains unclear whether they are able to retain this information for a biologically meaningful amount of time. To test this, captive red-footed tortoises (Chelonoidis carbonaria) were first trained to associate visual cues with specific qualities and quantities of food, and their preferences for the different reward values determined. They were then retested after an interval of 18 months. We found that the tortoises were able to retain the information they had learned about the cues as indicators of relative reward values over this interval, demonstrating a memory for the relative quantity and quality of food over an extended period of time. This is likely to impact directly on an animal's foraging decisions, such as the exploitation of seasonally varying resources, with obvious fitness implications for the individual; however, the implications may also extend to the ecological interactions in which the animal is involved, affecting processes such as herbivory and seed dispersal. © 2017 The Author(s).

  3. Overlap of food addiction and substance use disorders definitions: analysis of animal and human studies.

    Science.gov (United States)

    Hone-Blanchet, Antoine; Fecteau, Shirley

    2014-10-01

    Food has both homeostatic and hedonic components, which makes it a potent natural reward. Food related reward could therefore promote an escalation of intake and trigger symptoms associated to withdrawal, suggesting a behavioral parallel with substance abuse. Animal and human theoretical models of food reward and addiction have emerged, raising further interrogations on the validity of a bond between Substance Use Disorders, as clinically categorized in the DSM 5, and food reward. These models propose that highly palatable food items, rich in sugar and/or fat, are overly stimulating to the brain's reward pathways. Moreover, studies have also investigated the possibility of causal link between food reward and the contemporary obesity epidemic, with obesity being potentiated and maintained due to this overwhelming food reward. Although natural rewards are a hot topic in the definition and categorization of Substance Use Disorders, proofs of concept and definite evidence are still inconclusive. This review focuses on available results from experimental studies in animal and human models exploring the concept of food addiction, in an effort to determine if it depicts a specific phenotype and if there is truly a neurobiological similarity between food addiction and Substance Use Disorders. It describes results from sugar, fat and sweet-fat bingeing in rodent models, and behavioral and neurobiological assessments in different human populations. Although pieces of behavioral and neurobiological evidence supporting a food addiction phenotype in animals and humans are interesting, it seems premature to conclude on its validity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Effects of lesions of the nucleus accumbens core on choice between small certain rewards and large uncertain rewards in rats

    Directory of Open Access Journals (Sweden)

    Howes Nathan J

    2005-05-01

    Full Text Available Abstract Background Animals must frequently make choices between alternative courses of action, seeking to maximize the benefit obtained. They must therefore evaluate the magnitude and the likelihood of the available outcomes. Little is known of the neural basis of this process, or what might predispose individuals to be overly conservative or to take risks excessively (avoiding or preferring uncertainty, respectively. The nucleus accumbens core (AcbC is known to contribute to rats' ability to choose large, delayed rewards over small, immediate rewards; AcbC lesions cause impulsive choice and an impairment in learning with delayed reinforcement. However, it is not known how the AcbC contributes to choice involving probabilistic reinforcement, such as between a large, uncertain reward and a small, certain reward. We examined the effects of excitotoxic lesions of the AcbC on probabilistic choice in rats. Results Rats chose between a single food pellet delivered with certainty (p = 1 and four food pellets delivered with varying degrees of uncertainty (p = 1, 0.5, 0.25, 0.125, and 0.0625 in a discrete-trial task, with the large-reinforcer probability decreasing or increasing across the session. Subjects were trained on this task and then received excitotoxic or sham lesions of the AcbC before being retested. After a transient period during which AcbC-lesioned rats exhibited relative indifference between the two alternatives compared to controls, AcbC-lesioned rats came to exhibit risk-averse choice, choosing the large reinforcer less often than controls when it was uncertain, to the extent that they obtained less food as a result. Rats behaved as if indifferent between a single certain pellet and four pellets at p = 0.32 (sham-operated or at p = 0.70 (AcbC-lesioned by the end of testing. When the probabilities did not vary across the session, AcbC-lesioned rats and controls strongly preferred the large reinforcer when it was certain, and strongly

  5. Hidden sector behind the CKM matrix

    Science.gov (United States)

    Okawa, Shohei; Omura, Yuji

    2017-08-01

    The small quark mixing, described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix in the standard model, may be a clue to reveal new physics around the TeV scale. We consider a simple scenario that extra particles in a hidden sector radiatively mediate the flavor violation to the quark sector around the TeV scale and effectively realize the observed CKM matrix. The lightest particle in the hidden sector, whose contribution to the CKM matrix is expected to be dominant, is a good dark matter (DM) candidate. There are many possible setups to describe this scenario, so that we investigate some universal predictions of this kind of model, focusing on the contribution of DM to the quark mixing and flavor physics. In this scenario, there is an explicit relation between the CKM matrix and flavor violating couplings, such as four-quark couplings, because both are radiatively induced by the particles in the hidden sector. Then, we can explicitly find the DM mass region and the size of Yukawa couplings between the DM and quarks, based on the study of flavor physics and DM physics. In conclusion, we show that DM mass in our scenario is around the TeV scale, and the Yukawa couplings are between O (0.01 ) and O (1 ). The spin-independent DM scattering cross section is estimated as O (10-9) [pb]. An extra colored particle is also predicted at the O (10 ) TeV scale.

  6. Regulatory interactions of stress and reward on rat forebrain opioidergic and GABAergic circuitry.

    Science.gov (United States)

    Christiansen, A M; Herman, J P; Ulrich-Lai, Y M

    2011-03-01

    Palatable food intake reduces stress responses, suggesting that individuals may consume such ?comfort? food as self-medication for stress relief. The mechanism by which palatable foods provide stress relief is not known, but likely lies at the intersection of forebrain reward and stress regulatory circuits. Forebrain opioidergic and gamma-aminobutyric acid ergic signaling is critical for both reward and stress regulation, suggesting that these systems are prime candidates for mediating stress relief by palatable foods. Thus, the present study (1) determines how palatable ?comfort? food alters stress-induced changes in the mRNA expression of inhibitory neurotransmitters in reward and stress neurocircuitry and (2) identifies candidate brain regions that may underlie comfort food-mediated stress reduction. We used a model of palatable ?snacking? in combination with a model of chronic variable stress followed by in situ hybridization to determine forebrain levels of pro-opioid and glutamic acid decarboxylase (GAD) mRNA. The data identify regions within the extended amygdala, striatum, and hypothalamus as potential regions for mediating hypothalamic-pituitary-adrenal axis buffering following palatable snacking. Specifically, palatable snacking alone decreased pro-enkephalin-A (ENK) mRNA expression in the anterior bed nucleus of the stria terminalis (BST) and the nucleus accumbens, and decreased GAD65 mRNA in the posterior BST. Chronic stress alone increased ENK mRNA in the hypothalamus, nucleus accumbens, amygdala, and hippocampus; increased dynorphin mRNA in the nucleus accumbens; increased GAD65 mRNA in the anterior hypothalamus and BST; and decreased GAD65 mRNA in the dorsal hypothalamus. Importantly, palatable food intake prevented stress-induced gene expression changes in subregions of the hypothalamus, BST, and nucleus accumbens. Overall, these data suggest that complex interactions exist between brain reward and stress pathways and that palatable snacking can

  7. A Dynamic Hidden Forwarding Path Planning Method Based on Improved Q-Learning in SDN Environments

    Directory of Open Access Journals (Sweden)

    Yun Chen

    2018-01-01

    Full Text Available Currently, many methods are available to improve the target network’s security. The vast majority of them cannot obtain an optimal attack path and interdict it dynamically and conveniently. Almost all defense strategies aim to repair known vulnerabilities or limit services in target network to improve security of network. These methods cannot response to the attacks in real-time because sometimes they need to wait for manufacturers releasing corresponding countermeasures to repair vulnerabilities. In this paper, we propose an improved Q-learning algorithm to plan an optimal attack path directly and automatically. Based on this path, we use software-defined network (SDN to adjust routing paths and create hidden forwarding paths dynamically to filter vicious attack requests. Compared to other machine learning algorithms, Q-learning only needs to input the target state to its agents, which can avoid early complex training process. We improve Q-learning algorithm in two aspects. First, a reward function based on the weights of hosts and attack success rates of vulnerabilities is proposed, which can adapt to different network topologies precisely. Second, we remove the actions and merge them into every state that reduces complexity from O(N3 to O(N2. In experiments, after deploying hidden forwarding paths, the security of target network is boosted significantly without having to repair network vulnerabilities immediately.

  8. Consolidation power of extrinsic rewards: reward cues enhance long-term memory for irrelevant past events.

    Science.gov (United States)

    Murayama, Kou; Kitagami, Shinji

    2014-02-01

    Recent research suggests that extrinsic rewards promote memory consolidation through dopaminergic modulation processes. However, no conclusive behavioral evidence exists given that the influence of extrinsic reward on attention and motivation during encoding and consolidation processes are inherently confounded. The present study provides behavioral evidence that extrinsic rewards (i.e., monetary incentives) enhance human memory consolidation independently of attention and motivation. Participants saw neutral pictures, followed by a reward or control cue in an unrelated context. Our results (and a direct replication study) demonstrated that the reward cue predicted a retrograde enhancement of memory for the preceding neutral pictures. This retrograde effect was observed only after a delay, not immediately upon testing. An additional experiment showed that emotional arousal or unconscious resource mobilization cannot explain the retrograde enhancement effect. These results provide support for the notion that the dopaminergic memory consolidation effect can result from extrinsic reward.

  9. Extending overjustification: the effect of perceived reward-giver intention on response to rewards.

    Science.gov (United States)

    Forehand, M R

    2000-12-01

    The perceived intention model incorporates a new moderator, beliefs about reward-giver intention, into the overjustification paradigm. In 2 simulated shopping studies featuring products paired with promotional rewards, consumers who believed the marketer was promotion focused (reward used to encourage purchase) reported lower purchase intentions and brand attitudes for promoted products after promotion, whereas consumers who believed the marketer was reward focused (promotion used to distribute the reward) showed no attitude change. Promotion-focus beliefs lowered attitudes by heightening the contingency between the promotion and purchase and thereby increasing the perceived causal role of the reward. This effect was contingent on initial behavior--postpromotion attitude change occurred for consumers who actively engaged in product decisions but not for consumers who passively observed the choice sets.

  10. Ethanol induces impulsive-like responding in a delay-of-reward operant choice procedure: impulsivity predicts autoshaping.

    Science.gov (United States)

    Tomie, A; Aguado, A S; Pohorecky, L A; Benjamin, D

    1998-10-01

    Autoshaping conditioned responses (CRs) are reflexive and targeted motor responses expressed as a result of experience with reward. To evaluate the hypothesis that autoshaping may be a form of impulsive responding, within-subjects correlations between performance on autoshaping and impulsivity tasks were assessed in 15 Long-Evans hooded rats. Autoshaping procedures [insertion of retractable lever conditioned stimulus (CS) followed by the response-independent delivery of food (US)] were followed by testing for impulsive-like responding in a two-choice lever-press operant delay-of-reward procedure (immediate small food reward versus delayed large food reward). Delay-of-reward functions revealed two distinct subject populations. Subjects in the Sensitive group (n=7) were more impulsive-like, increasing immediate reward choices at longer delays for large reward, while those in the Insensitive group (n=8) responded predominantly on only one lever. During the prior autoshaping phase, the Sensitive group had performed more autoshaping CRs, and correlations revealed that impulsive subjects acquired the autoshaping CR in fewer trials. In the Sensitive group, acute injections of ethanol (0, 0.25, 0.50, 1.00, 1.50 g/kg) given immediately before delay-of-reward sessions yielded an inverted U-shaped dose-response curve with increased impulsivity induced by the 0.25, 0.50, and 1.00 g/kg doses of ethanol, while choice strategy of the Insensitive group was not influenced by ethanol dose. Ethanol induced impulsive-like responding only in rats that were flexible in their response strategy (Sensitive group), and this group also performed more autoshaping CRs. Data support the hypothesis that autoshaping and impulsivity are linked.

  11. Expected reward value and reward uncertainty have temporally dissociable effects on memory formation

    OpenAIRE

    Adcock, R; Clement, Nathaniel; Chiew, Kimberly; Dickerson, Kathryn; Stanek, Jessica

    2018-01-01

    Anticipating rewards has been shown to enhance memory formation. While substantial evidence implicates dopamine in this behavioral effect, the precise mechanisms remain ambiguous. Because dopamine nuclei show two distinct physiological signatures of reward prediction, we hypothesized two dissociable effects on memory formation. These two signatures are a phasic dopamine response immediately following a reward cue that encodes its expected value, and a sustained, ramping dopamine response that...

  12. TOTAL REWARDS MODEL IN ROMANIAN COMPANIES

    Directory of Open Access Journals (Sweden)

    Elena-Sabina HODOR

    2014-04-01

    Full Text Available Total Rewards Management is a subject of major importance for companies, because, by using models for this, firms can achieve their objectives of high performance. In order to analyse a validated total rewards model in Romanian Accounting and Consulting Companies, it is used The WorldatWork Total Rewards Model, which depict what contributes to applicant attraction and employee motivation and retention. Thus, the methodology of the previous survey is adjusted to the local context. The conclusions for the methodological aspects illustrate that the present research involves three strategic steps in order to achieve the objectives presented: the analysis of organizational environment of the companies from the sample, checking if Total Rewards Model proposed in the previous research is applicable for the same romanian companies from the previous survey, the analysing of the differences between results, and, if necessary, the adaptation of the model for Romania.

  13. Rewards and Opportunities for Successful Entrepreneurs.

    Science.gov (United States)

    Longenecker, Justin G.

    1983-01-01

    Among the rewards for entrepreneurs are money, independence, and a satisfying way of life. A variety of opportunities exist for those with the vision, ingenuity, and courage to exploit the potential of the market place. (SK)

  14. EuroPlus+ Reward / Alar Hammer

    Index Scriptorium Estoniae

    Hammer, Alar

    2000-01-01

    EuroPlus+ Reward on mitmes versioonis ilmunud inglise keele õppeprogramm, milles on ühendatud multimeedia võimalused ning distantsõpe ning mis loob täiesti uued võimalused keele omandamiseks arvuti abil

  15. Dorsomedial striatum lesions affect adjustment to reward uncertainty, but not to reward devaluation or omission.

    Science.gov (United States)

    Torres, Carmen; Glueck, Amanda C; Conrad, Shannon E; Morón, Ignacio; Papini, Mauricio R

    2016-09-22

    The dorsomedial striatum (DMS) has been implicated in the acquisition of reward representations, a proposal leading to the hypothesis that it should play a role in situations involving reward loss. We report the results of an experiment in which the effects of DMS excitotoxic lesions were tested in consummatory successive negative contrast (reward devaluation), autoshaping training with partial vs. continuous reinforcement (reward uncertainty), and appetitive extinction (reward omission). Animals with DMS lesions exhibited reduced lever pressing responding, but enhanced goal entries, during partial reinforcement training in autoshaping. However, they showed normal negative contrast, acquisition under continuous reinforcement (CR), appetitive extinction, and response facilitation in early extinction trials. Open-field testing also indicated normal motor behavior. Thus, DMS lesions selectively affected the behavioral adjustment to a situation involving reward uncertainty, producing a behavioral reorganization according to which goal tracking (goal entries) became predominant at the expense of sign tracking (lever pressing). This pattern of results shows that the function of the DMS in situations involving reward loss is not general, but restricted to reward uncertainty. We suggest that a nonassociative, drive-related process induced by reward uncertainty requires normal output from DMS neurons. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Individual differences in sensitivity to reward and punishment and neural activity during reward and avoidance learning.

    Science.gov (United States)

    Kim, Sang Hee; Yoon, HeungSik; Kim, Hackjin; Hamann, Stephan

    2015-09-01

    In this functional neuroimaging study, we investigated neural activations during the process of learning to gain monetary rewards and to avoid monetary loss, and how these activations are modulated by individual differences in reward and punishment sensitivity. Healthy young volunteers performed a reinforcement learning task where they chose one of two fractal stimuli associated with monetary gain (reward trials) or avoidance of monetary loss (avoidance trials). Trait sensitivity to reward and punishment was assessed using the behavioral inhibition/activation scales (BIS/BAS). Functional neuroimaging results showed activation of the striatum during the anticipation and reception periods of reward trials. During avoidance trials, activation of the dorsal striatum and prefrontal regions was found. As expected, individual differences in reward sensitivity were positively associated with activation in the left and right ventral striatum during reward reception. Individual differences in sensitivity to punishment were negatively associated with activation in the left dorsal striatum during avoidance anticipation and also with activation in the right lateral orbitofrontal cortex during receiving monetary loss. These results suggest that learning to attain reward and learning to avoid loss are dependent on separable sets of neural regions whose activity is modulated by trait sensitivity to reward or punishment. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  17. The circadian clock, reward and memory

    Directory of Open Access Journals (Sweden)

    Urs eAlbrecht

    2011-11-01

    Full Text Available During our daily activities, we experience variations in our cognitive performance, which is often accompanied by cravings for small rewards, such as consuming coffee or chocolate. This indicates that the time of day, cognitive performance and reward may be related to one another. This review will summarize data that describes the influence of the circadian clock on addiction and mood-related behavior and put the data into perspective in relation to memory processes.

  18. The Influence of Palatable Diets in Reward System Activation: A Mini Review

    Directory of Open Access Journals (Sweden)

    Isabel Cristina de Macedo

    2016-01-01

    Full Text Available The changes in eating patterns that have occurred in recent decades are an important cause of obesity. Food intake and energy expenditure are controlled by a complex neural system involving the hypothalamic centers and peripheral satiety system (gastrointestinal and pancreatic hormones. Highly palatable and caloric food disrupts appetite regulation; however, palatable foods induce pleasure and reward. The cafeteria diet is such a palatable diet and has been shown consistently to increase body weight and induce hyperplasia in animal obesity models. Moreover, palatable high-fat foods (such as those of the cafeteria diet can induce addiction-like deficits in brain reward function and are considered to be an important source of motivation that might drive overeating and contribute to the development of obesity. The mechanism of neural adaptation triggered by palatable foods is similar to those that have been reported for nondrug addictions and long-term drug use. Thus, this review attempts to describe the potential mechanisms that might lead to highly palatable diets, such as the cafeteria diet, triggering addiction, or compulsion through the reward system.

  19. Microwave background constraints on mixing of photons with hidden photons

    International Nuclear Information System (INIS)

    Mirizzi, Alessandro; Redondo, Javier; Sigl, Guenter

    2008-12-01

    Various extensions of the Standard Model predict the existence of hidden photons kinetically mixing with the ordinary photon. This mixing leads to oscillations between photons and hidden photons, analogous to the observed oscillations between different neutrino flavors. In this context, we derive new bounds on the photon-hidden photon mixing parameters using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of the Cosmic Background Explorer. Requiring the distortions of the CMB induced by the photon-hidden photon mixing to be smaller than experimental upper limits, this leads to a bound on the mixing angle χ 0 -7 - 10 -5 for hidden photon masses between 10 -14 eV and 10 -7 eV. This low-mass and low-mixing region of the hidden photon parameter space was previously unconstrained. (orig.)

  20. Microwave background constraints on mixing of photons with hidden photons

    Energy Technology Data Exchange (ETDEWEB)

    Mirizzi, Alessandro [Max-Planck-Institut fuer Physik, Muenchen (Germany); Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Sigl, Guenter [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2008-12-15

    Various extensions of the Standard Model predict the existence of hidden photons kinetically mixing with the ordinary photon. This mixing leads to oscillations between photons and hidden photons, analogous to the observed oscillations between different neutrino flavors. In this context, we derive new bounds on the photon-hidden photon mixing parameters using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of the Cosmic Background Explorer. Requiring the distortions of the CMB induced by the photon-hidden photon mixing to be smaller than experimental upper limits, this leads to a bound on the mixing angle {chi}{sub 0} hidden photon masses between 10{sup -14} eV and 10{sup -7} eV. This low-mass and low-mixing region of the hidden photon parameter space was previously unconstrained. (orig.)

  1. Identity-specific coding of future rewards in the human orbitofrontal cortex.

    Science.gov (United States)

    Howard, James D; Gottfried, Jay A; Tobler, Philippe N; Kahnt, Thorsten

    2015-04-21

    Nervous systems must encode information about the identity of expected outcomes to make adaptive decisions. However, the neural mechanisms underlying identity-specific value signaling remain poorly understood. By manipulating the value and identity of appetizing food odors in a pattern-based imaging paradigm of human classical conditioning, we were able to identify dissociable predictive representations of identity-specific reward in orbitofrontal cortex (OFC) and identity-general reward in ventromedial prefrontal cortex (vmPFC). Reward-related functional coupling between OFC and olfactory (piriform) cortex and between vmPFC and amygdala revealed parallel pathways that support identity-specific and -general predictive signaling. The demonstration of identity-specific value representations in OFC highlights a role for this region in model-based behavior and reveals mechanisms by which appetitive behavior can go awry.

  2. Fat and lean tissue accretion in relation to reward motivation in children.

    Science.gov (United States)

    De Decker, Annelies; De Clercq, Bart; Verbeken, Sandra; Wells, Jonathan C K; Braet, Caroline; Michels, Nathalie; De Henauw, Stefaan; Sioen, Isabelle

    2017-01-01

    'Reward sensitivity' explains inter-individual differences in the motivation to obtain rewards when reward cues are perceived. This psychobiological trait has been linked to higher consumption of palatable food when exposed to palatable food cues. The current study aims to examine if reward sensitivity explains differences in patterns of fat and lean tissue accretion over time in children. A longitudinal observational study with measurement waves in 2011 (baseline), 2012, 2013, and 2015 was conducted. The sample was a population-based Flemish cohort of children (n = 446, 50% boys and 5.5-12 years at baseline; 38.8% of the baseline sample also participated in 2015). Baseline reward sensitivity of the children was assessed by parent ratings on the Drive subscale of the Behavioral Inhibition System/Behavioral Approach System scales. Age- and sex-independent Fat and Lean Mass Index z-scores (zFMI and zLMI respectively) were computed for each study wave based on air-displacement plethysmography. In girls, but not boys, reward sensitivity was positively associated with the baseline zFMI and zLMI (95% confidence intervals of unstandardized estimates: 0.01 to 0.11 and 0.01 to 0.10 respectively, P values 0.01 and 0.02 respectively). Further, reward sensitivity explained 14.8% and 11.6% of the change in girls' zFMI and zLMI respectively over four years: the zFMI and zLMI increased and decreased respectively in high reward sensitive girls (95% confidence intervals of unstandardized estimates: 0.01 to 0.11 and -0.12 to -0.01 respectively, P values 0.01 and 0.02 respectively). Hence, girls high in reward sensitivity had significantly higher adiposity gain over four years parallel with lower increase in lean mass than was expected on the basis of their age and height. These results may help to identify appropriate targets for interventions for obesity prevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. The role of sweet and savoury taste in food intake and food preferences

    OpenAIRE

    Griffioen-Roose, S.

    2012-01-01

    Background and aim The sensory attributes of food play a key role in the selection and termination of meals and their rewarding properties. The majority of our foods are either sweet or savoury tasting. In addition, within our food range, savoury-tasting foods contain in general higher levels of protein. The effect of specific taste modalities on human food intake, however, requires further clarification. The primary aim of this thesis was to investigate the role of sweet and savoury taste ...

  4. Common neuroplasticity mechanisms underlying drugs and food reward

    OpenAIRE

    Guegan, Thomas, 1983-

    2013-01-01

    La adicción a las drogas de abuso y determinados trastornos alimentarios comparten varios síntomas comportamentales. Algunos estudios han sugerido que el consumo excesivo de drogas y de comida palatable podrían producir alteraciones neuronales similares en el circuito cerebral de recompensa. En esta tesis, hemos demostrado que un aprendizaje operante prolongado con comida palatable provoca la aparición de alteraciones comportamentales y cambios de plasticidad estructurales en el circuito meso...

  5. Upregulation of gene expression in reward-modulatory striatal opioid systems by sleep loss.

    Science.gov (United States)

    Baldo, Brian A; Hanlon, Erin C; Obermeyer, William; Bremer, Quentin; Paletz, Elliott; Benca, Ruth M

    2013-12-01

    Epidemiological studies have shown a link between sleep loss and the obesity 'epidemic,' and several observations indicate that sleep curtailment engenders positive energy balance via increased palatable-food 'snacking.' These effects suggest alterations in reward-modulatory brain systems. We explored the effects of 10 days of sleep deprivation in rats on the expression of striatal opioid peptide (OP) genes that subserve food motivation and hedonic reward, and compared effects with those seen in hypothalamic energy balance-regulatory systems. Sleep-deprived (Sleep-Dep) rats were compared with yoked forced-locomotion apparatus controls (App-Controls), food-restricted rats (Food-Restrict), and unmanipulated controls (Home-Cage). Detection of mRNA levels with in situ hybridization revealed a subregion-specific upregulation of striatal preproenkephalin and prodynorhin gene expression in the Sleep-Dep group relative to all other groups. Neuropeptide Y (NPY) gene expression in the hippocampal dentate gyrus and throughout neocortex was also robustly upregulated selectively in the Sleep-Dep group. In contrast, parallel gene expression changes were observed in the Sleep-Dep and Food-Restrict groups in hypothalamic energy-sensing systems (arcuate nucleus NPY was upregulated, and cocaine- and amphetamine-regulated transcript was downregulated), in alignment with leptin suppression in both groups. Together, these results reveal a novel set of sleep deprivation-induced transcriptional changes in reward-modulatory peptide systems, which are dissociable from the energy-balance perturbations of sleep loss or the potentially stressful effects of the forced-locomotion procedure. The recruitment of telencephalic food-reward systems may provide a feeding drive highly resistant to feedback control, which could engender obesity through the enhancement of palatable feeding.

  6. Reward memory relieves anxiety-related behavior through synaptic strengthening and protein kinase C in dentate gyrus.

    Science.gov (United States)

    Lei, Zhuofan; Liu, Bei; Wang, Jin-Hui

    2016-04-01

    Anxiety disorders are presumably associated with negative memory. Psychological therapies are widely used to treat this mental deficit in human beings based on the view that positive memory competes with negative memory and relieves anxiety status. Cellular and molecular processes underlying psychological therapies remain elusive. Therefore, we have investigated its mechanisms based on a mouse model in which food reward at one open-arm of the elevated plus-maze was used for training mice to form reward memory and challenge the open arms. Mice with the reward training showed increased entries and stay time in reward open-arm versus neutral open-arm as well as in open-arms versus closed-arms. Accompanying with reward memory formation and anxiety relief, glutamatergic synaptic transmission in dentate gyrus in vivo and dendritic spines in granule cells became upregulated. This synaptic up-regulation was accompanied by the expression of more protein kinase C (PKC) in the dendritic spines. The inhibition of PKC by chelerythrine impaired the formation of reward memory, the relief of anxiety-related behavior and the up-regulation of glutamate synapses. Our results suggest that reward-induced positive memory relieves mouse anxiety-related behavior by strengthening synaptic efficacy and PKC in the hippocampus, which imply the underlying cellular and molecular processes involved in the beneficial effects of psychological therapies treating anxiety disorders. © 2015 Wiley Periodicals, Inc.

  7. Neural correlates of reward processing in healthy siblings of patients with schizophrenia : Reward processing in schizophrenia siblings

    NARCIS (Netherlands)

    Hanssen, E.M.E.

    2015-01-01

    Deficits in motivational behavior and psychotic symptoms often observed in schizophrenia (SZ) may be driven by dysfunctional reward processing (RP). RP can be divided in two different stages; reward anticipation and reward consumption. Aberrant processing during reward anticipation seems to be

  8. 'Goats that stare at men': dwarf goats alter their behaviour in response to human head orientation, but do not spontaneously use head direction as a cue in a food-related context.

    Science.gov (United States)

    Nawroth, Christian; von Borell, Eberhard; Langbein, Jan

    2015-01-01

    Recently, comparative research on the mechanisms and species-specific adaptive values of attributing attentive states and using communicative cues has gained increased interest, particularly in non-human primates, birds, and dogs. Here, we investigate these phenomena in a farm animal species, the dwarf goat (Capra aegagrus hircus). In the first experiment, we investigated the effects of different human head and body orientations, as well as human experimenter presence/absence, on the behaviour of goats in a food-anticipating paradigm. Over a 30-s interval, the experimenter engaged in one of four different postures or behaviours (head and body towards the subject-'Control', head to the side, head and body away from the subject, or leaving the room) before delivering a reward. We found that the level of subjects' active anticipatory behaviour was highest in the control condition and decreased with a decreasing level of attention paid to the subject by the experimenter. Additionally, goats 'stared' (i.e. stood alert) at the experimental set-up for significantly more time when the experimenter was present but paid less attention to the subject ('Head' and 'Back' condition) than in the 'Control' and 'Out' conditions. In a second experiment, the experimenter provided different human-given cues that indicated the location of a hidden food reward in a two-way object choice task. Goats were able to use both 'Touch' and 'Point' cues to infer the correct location of the reward but did not perform above the level expected by chance in the 'Head only' condition. We conclude that goats are able to differentiate among different body postures of a human, including head orientation; however, despite their success at using multiple physical human cues, they fail to spontaneously use human head direction as a cue in a food-related context.

  9. VISIBLE COSTS AND HIDDEN COSTS IN THE BAKING INDUSTRY

    Directory of Open Access Journals (Sweden)

    Criveanu Maria

    2013-04-01

    Full Text Available Hidden costs are present in the activity of any company, hardly identified in the traditional administrative accounting. The high levels of the hidden costs and their unknown presence have serious consequences on the decisions made by the managers. This paper aims at presenting some aspects related to the hidden costs that occur in the activity of the companies in the baking industry and the possibilities to reduce their level.

  10. The role of rewarding and novel events in facilitating memory persistence in a separate spatial memory task

    Science.gov (United States)

    Salvetti, Beatrice; Morris, Richard G.M.; Wang, Szu-Han

    2014-01-01

    Many insignificant events in our daily life are forgotten quickly but can be remembered for longer when other memory-modulating events occur before or after them. This phenomenon has been investigated in animal models in a protocol in which weak memories persist longer if exploration in a novel context is introduced around the time of memory encoding. This study aims to understand whether other types of rewarding or novel tasks, such as rewarded learning in a T-maze and novel object recognition, can also be effective memory-modulating events. Rats were trained in a delayed matching-to-place task to encode and retrieve food locations in an event arena. Weak encoding with only one food pellet at the sample location induced memory encoding but forgetting over 24 h. When this same weak encoding was followed by a rewarded task in a T-maze, the memory persisted for 24 h. Moreover, the same persistence of memory over 24 h could be achieved by exploration in a novel box or by a rewarded T-maze task after a “non-rewarded” weak encoding. When the one-pellet weak encoding was followed by novel object exploration, the memory did not persist at 24 h. Together, the results confirm that place encoding is possible without explicit reward, and that rewarded learning in a separate task lacking novelty can be an effective memory-modulating event. The behavioral and neurobiological implications are discussed. PMID:24429424

  11. Sensitivity to Temporal Reward Structure in Amygdala Neurons

    OpenAIRE

    Bermudez, Maria A.; Göbel, Carl; Schultz, Wolfram

    2012-01-01

    Summary The time of reward and the temporal structure of reward occurrence fundamentally influence behavioral reinforcement and decision processes [1–11]. However, despite knowledge about timing in sensory and motor systems [12–17], we know little about temporal mechanisms of neuronal reward processing. In this experiment, visual stimuli predicted different instantaneous probabilities of reward occurrence that resulted in specific temporal reward structures. Licking behavior demonstrated that...

  12. The CB1 Receptor as an Important Mediator of Hedonic Reward Processing

    Science.gov (United States)

    Friemel, Chris M; Zimmer, Andreas; Schneider, Miriam

    2014-01-01

    The endocannabinoid (ECB) system has emerged recently as a key mediator for reward processing. It is well known that cannabinoids affect appetitive learning processes and can induce reinforcing and rewarding effects. However, the involvement of the ECB system in hedonic aspects of reward-related behavior is not completely understood. With the present study, we investigated the modulatory role of the ECB system on hedonic perception, measured by the pleasure attenuated startle (PAS) paradigm for a palatable food reward. Here, a conditioned odor is thought to induce a pleasant affective state that attenuates an aversive reflex—the acoustic startle response. Modulatory effects of the CB1 receptor antagonist/inverse agonist SR1411716 and the cannabinoid agonist WIN 55 212-2 on PAS were examined in rats. PAS was also measured in CB1 receptor knockout (KO) and wild-type (WT) mice. Pharmacological inhibition as well as the absence of CB1 receptors was found to reduce PAS, whereas WIN 55 212-2 administration increased PAS. Finally, presentation of a conditioned reward cue was found to induce striatal FosB/ΔFosB expression in WT mice, but not in KO mice, indicating a reduced stimulation of reward-related brain regions in conditioned KO mice by odor presentation. We here show that in addition to our previous studies in rats, PAS may also serve as a valuable and suitable measure to assess hedonic processing in mice. Our data further indicate that the ECB system, and in particular CB1 receptor signaling, appears to be highly important for the mediation of hedonic aspects of reward processing. PMID:24718372

  13. Designing for psychological change: individuals' reward and cost valuations in weight management.

    Science.gov (United States)

    Hsu, Anne; Blandford, Ann

    2014-06-26

    Knowledge of the psychological constructs that underlie behavior offers valuable design opportunities for persuasive systems. We use the decision theory, which describes how behavior is underpinned by reward-cost valuations, as a framework for investigating such psychological constructs to deliver design objectives for weight management technologies. We applied a decision theory-based analysis in the domain of weight management to understand the rewards and costs that surround individuals' weight management behaviors, with the aim of uncovering design opportunities for weight management technologies. We conducted qualitative interviews with 15 participants who were or had been trying to lose weight. Thematic analysis was used to extract themes that covered the rewards and costs surrounding weight management behaviors. We supplemented our qualitative study with a quantitative survey of 100 respondents investigating the extent to which they agreed with statements reflecting themes from the qualitative study. The primary obstacles to weight management were the rewards associated with unhealthy choices, such as the pleasures of unhealthy foods and unrestricted consumption in social situations, and the significant efforts required to change habits, plan, and exercise. Psychological constructs that supported positive weight management included feeling good after making healthy choices, being good to oneself, experiencing healthy yet still delicious foods, and receiving social support and encouraging messages (although opinions about encouraging messages was mixed). A rewards-costs driven enquiry revealed a wide range of psychological constructs that contribute to discouraging and supporting weight management. The constructs extracted from our qualitative study were verified by our quantitative survey, in which the majority of respondents also reported similar thoughts and feelings. This understanding of the rewards and costs surrounding weight management offers a range

  14. Compressing the hidden variable space of a qubit

    International Nuclear Information System (INIS)

    Montina, Alberto

    2011-01-01

    In previously exhibited hidden variable models of quantum state preparation and measurement, the number of continuous hidden variables describing the actual state of single realizations is never smaller than the quantum state manifold dimension. We introduce a simple model for a qubit whose hidden variable space is one-dimensional, i.e., smaller than the two-dimensional Bloch sphere. The hidden variable probability distributions associated with quantum states satisfy reasonable criteria of regularity. Possible generalizations of this shrinking to an N-dimensional Hilbert space are discussed.

  15. Zipf exponent of trajectory distribution in the hidden Markov model

    Science.gov (United States)

    Bochkarev, V. V.; Lerner, E. Yu

    2014-03-01

    This paper is the first step of generalization of the previously obtained full classification of the asymptotic behavior of the probability for Markov chain trajectories for the case of hidden Markov models. The main goal is to study the power (Zipf) and nonpower asymptotics of the frequency list of trajectories of hidden Markov frequencys and to obtain explicit formulae for the exponent of the power asymptotics. We consider several simple classes of hidden Markov models. We prove that the asymptotics for a hidden Markov model and for the corresponding Markov chain can be essentially different.

  16. Zipf exponent of trajectory distribution in the hidden Markov model

    International Nuclear Information System (INIS)

    Bochkarev, V V; Lerner, E Yu

    2014-01-01

    This paper is the first step of generalization of the previously obtained full classification of the asymptotic behavior of the probability for Markov chain trajectories for the case of hidden Markov models. The main goal is to study the power (Zipf) and nonpower asymptotics of the frequency list of trajectories of hidden Markov frequencys and to obtain explicit formulae for the exponent of the power asymptotics. We consider several simple classes of hidden Markov models. We prove that the asymptotics for a hidden Markov model and for the corresponding Markov chain can be essentially different

  17. The Second International Conference on Nutrition: Implications for Hidden Hunger.

    Science.gov (United States)

    Amoroso, Leslie

    2016-01-01

    The Second International Conference on Nutrition (ICN2) was jointly organized by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) and was held at the FAO Headquarters in Rome, Italy, from 19 to 21 November 2014. The ICN2 was a high-level intergovernmental meeting that focused global attention on addressing malnutrition in all its forms: undernutrition, including micronutrient deficiencies, overweight, and obesity. The ICN2 was held to specifically address the persistent and unacceptably high levels of malnutrition. Despite much progress in reducing hunger globally, 795 million people remain undernourished, over 2 billion people suffer from various micronutrient deficiencies, and an estimated 161 million children under 5 years of age are stunted, 99 million underweight, and 51 million wasted. Meanwhile, more than 600 million adults are obese. Global problems require global solutions. The ICN2 brought together national policy-makers from food, agriculture, health, education, social protection and other relevant sectors to address the complex problem of malnutrition through a multi-sectoral approach. Two outcome documents - the Rome Declaration on Nutrition and the Framework for Action - were endorsed by participating governments at the Conference, committing world leaders to establishing national policies aimed at eradicating malnutrition in all its forms and transforming food systems to make nutritious diets available to all. The Rome Declaration on Nutrition is a political statement of 10 commitments for more effective and coordinated action to improve nutrition, while the Framework for Action is a voluntary technical guide of 60 recommendations for the implementation of the political commitments. This chapter provides information on the ICN2 and its outcomes as well as follow-up activities. Emphasis is placed on the Rome Declaration on Nutrition and the Framework for Action, with special focus on hidden

  18. Mechanisms of impulsive choice: III. The role of reward processes

    Science.gov (United States)

    Marshall, Andrew T.

    2015-01-01

    Two experiments examined the relationship between reward processing and impulsive choice. In Experiment 1, rats chose between a smaller-sooner (SS) reward (1 pellet, 10 s) and a larger-later (LL) reward (1, 2, and 4 pellets, 30 s). The rats then experienced concurrent variable-interval 30-s schedules with variations in reward magnitude to evaluate reward magnitude discrimination. LL choice behavior positively correlated with reward magnitude discrimination. In Experiment 2, rats chose between an SS reward (1 pellet, 10 s) and an LL reward (2 and 4 pellets, 30 s). The rats then received either a reward intervention which consisted of concurrent fixed-ratio schedules associated with different magnitudes to improve their reward magnitude discrimination, or a control task. All rats then experienced a post-intervention impulsive choice task followed by a reward magnitude discrimination task to assess intervention efficacy. The rats that received the intervention exhibited increases in post-intervention LL choice behavior, and made more responses for larger-reward magnitudes in the reward magnitude discrimination task, suggesting that the intervention heightened sensitivities to reward magnitude. The results suggest that reward magnitude discrimination plays a key role in individual differences in impulsive choice, and could be a potential target for further intervention developments. PMID:26506254

  19. Reward System Activation in Response to Alcohol Advertisements Predicts College Drinking.

    Science.gov (United States)

    Courtney, Andrea L; Rapuano, Kristina M; Sargent, James D; Heatherton, Todd F; Kelley, William M

    2018-01-01

    In this study, we assess whether activation of the brain's reward system in response to alcohol advertisements is associated with college drinking. Previous research has established a relationship between exposure to alcohol marketing and underage drinking. Within other appetitive domains, the relationship between cue exposure and behavioral enactment is known to rely on activation of the brain's reward system. However, the relationship between neural activation to alcohol advertisements and alcohol consumption has not been studied in a nondisordered population. In this cross-sectional study, 53 college students (32 women) completed a functional magnetic resonance imaging scan while viewing alcohol, food, and control (car and technology) advertisements. Afterward, they completed a survey about their alcohol consumption (including frequency of drinking, typical number of drinks consumed, and frequency of binge drinking) over the previous month. In 43 participants (24 women) meeting inclusion criteria, viewing alcohol advertisements elicited activation in the left orbitofrontal cortex and bilateral ventral striatum-regions of the reward system that typically activate to other appetitive rewards and relate to consumption behaviors. Moreover, the level of self-reported drinking correlated with the magnitude of activation in the left orbitofrontal cortex. Results suggest that alcohol cues are processed within the reward system in a way that may motivate drinking behavior.

  20. Behavioral responses to inequity in reward distribution and working effort in crows and ravens.

    Directory of Open Access Journals (Sweden)

    Claudia A F Wascher

    Full Text Available Sensitivity to inequity is considered to be a crucial cognitive tool in the evolution of human cooperation. The ability has recently been shown also in primates and dogs, raising the question of an evolutionary basis of inequity aversion. We present first evidence that two bird species are sensitive to other individuals' efforts and payoffs. In a token exchange task we tested both behavioral responses to inequity in the quality of reward (preferred versus non-preferred food and to the absence of reward in the presence of a rewarded partner, in 5 pairs of corvids (6 crows, 4 ravens. Birds decreased their exchange performance when the experimental partner received the reward as a gift, which indicates that they are sensitive to other individuals' working effort. They also decreased their exchange performance in the inequity compared with the equity condition. Notably, corvids refused to take the reward after a successful exchange more often in the inequity compared with the other conditions. Our findings indicate that awareness to other individuals' efforts and payoffs may evolve independently of phylogeny in systems with a given degree of social complexity.