WorldWideScience

Sample records for aversive therapy

  1. On Not to be Gay: Aversion therapy and transformation of the self in Postsocialist China

    Directory of Open Access Journals (Sweden)

    H Bao

    2012-11-01

    Full Text Available In this article, through a critical reading of the published diaries written by gay ‘patients’ who received aversion therapy in south China in the 1990s, I examine how the transformation of subjectivities from gay to straight was made possible by such ‘self-technologizing’ practices as writing and communication. I also consider the centrality of the body and affect in the process of subject (transformation, and ask how a new, coherent and authentic ‘self’ was fabricated through bodily and affective experiences. This discussion not only reveals the social construction of the self as central to China’s postsocialist governmentality, but also the central role that gender and sexuality play in processes of self-formation.

  2. Optimizing an Aversion Feeding Therapy Protocol for a Child with Food Protein-Induced Enterocolitis Syndrome (FPIES)

    OpenAIRE

    Mattingly, Rhonda; Mukkada, Vincent; Smith, Alan; Pitts, Teresa

    2015-01-01

    This case study examines the difficulties of treating food aversion in a 9-month old child with a diagnosis of Food Protein-Induced Enterocolitis Syndrome (FPIES). Given the need to first identify a set of “safe foods” with which to work, the twin goals of doing food challenges and minimizing aversion are initially not complimentary, and require an approach outside the standard of care. The chosen plan encouraged flexibility and a positive relationship with feeding-related items, while only i...

  3. Reception of Aversive Taste.

    Science.gov (United States)

    Lunceford, Blair E; Kubanek, Julia

    2015-09-01

    Many organisms encounter noxious or unpalatable compounds in their diets. Thus, a robust reception-system for aversive taste is necessary for an individual's survival; however, mechanisms for perceiving aversive taste vary among organisms. Possession of a system sensitive to aversive taste allows for recognition of a vast array of noxious molecules via membrane-bound receptors, co-receptors, and ion channels. These receptor-ligand interactions trigger signal transduction pathways resulting in activation of nerves and in neural processing, which in turn dictates behavior, including rejection of the noxious item. The impacts of these molecular processes on behavior differ among species, and these differences have impacts at the ecosystem level by driving feeding-behavior, organization of communities, and ultimately, speciation. For example, when comparing mammalian carnivores and herbivores, it is not surprising that herbivores that encounter a variety of toxic plants in their diets express a larger number of aversive taste receptors than carnivores. Comparing the molecular mechanisms and ecological consequences of aversive-taste reception among organisms in a variety of types of ecosystems and ecological niches will illuminate the role of taste in ecology and evolution. PMID:26025470

  4. Loss Aversion and Individual Characteristics

    DEFF Research Database (Denmark)

    Hjorth, Katrine; Fosgerau, Mogens

    2011-01-01

    Many studies have shown that loss aversion affects the valuation of non-market goods. Using stated choice data, this paper presents an empirical investigation of how individual-level loss aversion varies with observable personal characteristics and with the choice context. We investigate loss...

  5. The limits of catastrophe aversion.

    Science.gov (United States)

    Peterson, Martin

    2002-06-01

    We discuss the management of catastrophe-risks from a theoretical point of view. The concept of a catastrophe is informally and formally defined, and a number of desiderata for catastrophe-averse decision rules are introduced. However, the proposed desiderata turn out to be mutually inconsistent. As a consequence of this result, it is argued that the "rigid" form of catastrophe aversion articulated by, for example, the maximin rule, the maximum probable loss rule, (some versions of) the precautionary principle, and the rule proposed in Ekenberg et al. (1997, 2000) should be given up. An alternative form of "non-rigid" catastrophe aversion is considered. PMID:12088231

  6. Lying aversion and prosocial behaviour

    CERN Document Server

    Biziou-van-Pol, Laura; Novaro, Arianna; Liberman, Andrés Occhipinti; Capraro, Valerio

    2015-01-01

    The focus of this paper is the moral conflict between lying aversion and prosociality. What does telling a white lie signal about a person's prosocial tendencies? How does believing a possibly untruthful message signal about a listener's prosocial tendencies? To answer these questions, we conducted a 2x3 experiment. In the first stage we measured altruistic tendencies using a Dictator Game and cooperative tendencies using a Prisoner's dilemma. In the second stage, we used a sender-receiver game to measure aversion to telling a Pareto white lie (i.e., a lie that helps both the liar and the listener), aversion to telling an altruistic white lie (i.e., a lie that helps the listener at the expense of the liar), and skepticism towards believing a possibly untruthful message. We found three major results: (i) both altruism and cooperation are positively correlated with aversion to telling a Pareto white lie; (ii) neither altruism nor cooperation are significantly correlated with aversion to telling an altruistic wh...

  7. Default Risk and Risk Averse International Investors

    OpenAIRE

    Lizarazo, Sandra

    2010-01-01

    This paper develops a quantitative model of debt and default for small open economies that interact with risk averse international investors. The model developed here extends the recent work on the analysis of endogenous default risk to the case in which international investors are risk averse agents with decreasing absolute risk aversion (DARA). By incorporating risk averse investors who trade with a single emerging economy, the present model o ers two main improvements over the standard cas...

  8. Comparative Risk Aversion under Background Risk Revisited

    OpenAIRE

    Masamitsu Ohnishi; Yusuke Osaki

    2010-01-01

    This paper determines a new sufficient condition of the (von Neumann-Morgenstern) utility function that preserves comparative risk aversion under background risk. It is the single crossing condition of risk aversion. Because this condition requires monotonicity in the local sense, it may satisfy the U-shaped risk aversion observed in the recent empirical literature.

  9. Ambiguity aversion in rhesus macaques

    Directory of Open Access Journals (Sweden)

    BenjaminHayden

    2010-09-01

    Full Text Available People generally prefer risky options, which have fully specified outcome probabilities, to ambiguous options, which have unspecified probabilities. This preference, formalized in economics, is strong enough that people will reliably prefer a risky option to an ambiguous option with a greater expected value. Explanations for ambiguity aversion often invoke uniquely human faculties like language, self-justification, or a desire to avoid public embarrassment. Challenging these ideas, here we demonstrate that a preference for unambiguous options is shared with rhesus macaques. We trained four monkeys to choose between pairs of options that both offered explicitly cued probabilities of large and small juice outcomes. We then introduced occasional trials where one of the options was obscured and examined their resulting preferences; we ran humans in a parallel experiment on a nearly identical task. We found that monkeys reliably preferred risky options to ambiguous ones, even when this bias was costly, closely matching the behavior of humans in the analogous task. Notably, ambiguity aversion varied parametrically with the extent of ambiguity. As expected, ambiguity aversion gradually declined as monkeys learned the underlying probability distribution of rewards. These data indicate that ambiguity aversion reflects fundamental cognitive biases shared with other animals rather than uniquely human factors guiding decisions.

  10. On loss aversion in bimatrix games

    OpenAIRE

    Driesen, B.; Perea, A.; Peters, H

    2007-01-01

    In this article three different types of loss aversion equilibria in bimatrix games are studied. Loss aversion equilibria are Nash equilibria of games where players are loss averse and where the reference points—points below which they consider payoffs to be losses—are endogenous to the equilibrium calculation. The first type is the fixed point loss aversion equilibrium, introduced in Shalev (2000; Int. J. Game Theory 29(2):269) under the name of ‘myopic loss aversion equilibrium.’ There, the...

  11. Inequality Aversion and Risk Attitudes

    OpenAIRE

    Ramos Morilla, Xavier; Ferrer-i-Carbonell, Ada

    2010-01-01

    Using self reported measures of life satisfaction and risk attitudes, we empirically test whether there is a relationship between individuals inequality and risk aversion. The empirical analysis uses the German SOEP household panel for the years 1997 to 2007 to conclude that the negative effect of inequality measured by the sample gini coefficient by year and federal state is larger for those individuals who report to be less willing to take risks. Nevertheless, the empirical results suggest ...

  12. Leverage Aversion and Risk Parity

    DEFF Research Database (Denmark)

    Asness, Clifford; Frazzini, Andrea; Heje Pedersen, Lasse

    2012-01-01

    The authors show that leverage aversion changes the predictions of modern portfolio theory: Safer assets must offer higher risk-adjusted returns than riskier assets. Consuming the high risk-adjusted returns of safer assets requires leverage, creating an opportunity for investors with the ability to...... apply leverage. Risk parity portfolios exploit this opportunity by equalizing the risk allocation across asset classes, thus overweighting safer assets relative to their weight in the market portfolio....

  13. Financial Intermediation with Risk Aversion

    OpenAIRE

    Hellwig, Martin

    1998-01-01

    The paper extends Diamond's (1984) analysis of financial intermediation to allow for risk aversion of the intermediary. It shows that, as in the case of risk neutrality, the agency costs of external funds provided to an intermediary are relatively small if the intermediary is financing many entrepreneurs with stochastically independent returns. Even though the intermediary is adding rather than subdividing risks, the underlying large-numbers argument is not invalidated by the presence of risk...

  14. Volatility, Investment and Disappointment Aversion

    OpenAIRE

    Joshua Aizenman; Nancy Marion

    1995-01-01

    This study uncovers a statistically significant negative correlation between volatility and private investment over the 1970-93 period in a set of almost fifty developing countries and provides a possible interpretation of this result by using the disappointment- aversion expected utility framework first described by Gul (1991). We consider a number of different volatility measures related to domestic policies or to external factors. As the various volatility measures tend to be positively co...

  15. Inequality Aversion and Antisocial Punishment

    OpenAIRE

    Thöni, Christian

    2011-01-01

    Antisocial punishment - punishment of pro-social cooperators - has shown to be detrimental for the efficiency of informal punishment mechanisms in public goods games. The motives behind antisocial punishment acts are not yet well understood. This article shows that inequality aversion predicts antisocial punishment in public goods games with punishment. The model by Fehr and Schmidt (1999) allows to derive conditions under which antisocial punishment occurs. With data from three studies on pu...

  16. High salt recruits aversive taste pathways

    OpenAIRE

    Oka, Yuki; Butnaru, Matthew; von Buchholtz, Lars; Ryba, Nicholas J.P.; Zuker, Charles S.

    2013-01-01

    In the tongue, distinct classes of taste receptor cells detect the five basic tastes, sweet, sour, bitter, sodium salt, and umami 1,2 . Among these qualities, bitter and sour stimuli are innately aversive, whereas sweet and umami are appetitive, and generally attractive to animals. In contrast, salty taste is unique in that increasing salt concentration fundamentally transforms an innately appetitive stimulus into a powerfully aversive one 3–7 . This appetitive-aversive balance helps maintain...

  17. Indexation Rules, Risk Aversion, and Imperfect Information

    OpenAIRE

    C. Benassi; A. E. Scorcu

    2003-01-01

    Nominal wage adjustment is modeled as resulting from bargaining between a risk neutral firm and a risk averse worker, in an environment where the rate of inflation is a random variable. Risk aversion makes for endogenous indexation arrangements, which deliver partial indexation as they exploit imperfect inflation indices; risk aversion also generates a positive correlation between indexation and inflation variance. The model suggests a distinction between complete vs incomplete inflation adju...

  18. Recovering risk aversion from options

    OpenAIRE

    Bliss, Robert R.; Nikolaos Panigirtzoglou

    2001-01-01

    Cross-sections of option prices embed the risk-neutral probability densities functions (PDFs) for the future values of the underlying asset. Theory suggests that risk-neutral PDFs differ from market expectations due to risk premia. Using a utility function to adjust the risk-neutral PDF to produce subjective PDFs, we can obtain measures of the risk aversion implied in option prices. Using FTSE 100 and S&P 500 options, and both power and exponential utility functions, we show that subjective P...

  19. Appetitive vs. Aversive conditioning in humans

    OpenAIRE

    Andreatta, Marta; Pauli, Paul

    2015-01-01

    In classical conditioning, an initially neutral stimulus (conditioned stimulus, CS) becomes associated with a biologically salient event (unconditioned stimulus, US), which might be pain (aversive conditioning) or food (appetitive conditioning). After a few associations, the CS is able to initiate either defensive or consummatory responses, respectively. Contrary to aversive conditioning, appetitive conditioning is rarely investigated in humans, although its importance for normal and patholog...

  20. Appetitive vs. Aversive Conditioning in Humans

    OpenAIRE

    Marta Andreatta

    2015-01-01

    In classical conditioning, an initially neutral stimulus (conditioned stimulus, CS) becomes associated with a biologically salient event (unconditioned stimulus, US), which might be pain (aversive conditioning) or food (appetitive conditioning). After a few associations, the CS is able to initiate either defensive or consummatory responses, respectively. Contrary to aversive conditioning, appetitive conditioning is rarely investigated in humans, although its importance for normal and patholog...

  1. Incidental fear cues increase monetary loss aversion.

    Science.gov (United States)

    Schulreich, Stefan; Gerhardt, Holger; Heekeren, Hauke R

    2016-04-01

    In many everyday decisions, people exhibit loss aversion-a greater sensitivity to losses relative to gains of equal size. Loss aversion is thought to be (at least partly) mediated by emotional-in particular, fear-related-processes. Decision research has shown that even incidental emotions, which are unrelated to the decision at hand, can influence decision making. The effect of incidental fear on loss aversion, however, is thus far unclear. In two studies, we experimentally investigated how incidental fear cues, presented during (Study 1) or before (Study 2) choices to accept or reject mixed gambles over real monetary stakes, influence monetary loss aversion. We find that the presentation of fearful faces, relative to the presentation of neutral faces, increased risk aversion-an effect that could be attributed to increased loss aversion. The size of this effect was moderated by psychopathic personality: Fearless dominance, in particular its interpersonal facet, but not self-centered impulsivity, attenuated the effect of incidental fear cues on loss aversion, consistent with reduced fear reactivity. Together, these results highlight the sensitivity of loss aversion to the affective context. (PsycINFO Database Record PMID:26595436

  2. Risk Aversion, Price Uncertainty and Irreversible Investments

    NARCIS (Netherlands)

    van den Goorbergh, R.W.J.; Huisman, K.J.M.; Kort, P.M.

    2003-01-01

    This paper generalizes the theory of irreversible investment under uncertainty by allowing for risk averse investors in the absence of com-plete markets.Until now this theory has only been developed in the cases of risk neutrality, or risk aversion in combination with complete markets.Within a gener

  3. Health Security and Risk Aversion.

    Science.gov (United States)

    Herington, Jonathan

    2016-09-01

    Health security has become a popular way of justifying efforts to control catastrophic threats to public health. Unfortunately, there has been little analysis of the concept of health security, nor the relationship between health security and other potential aims of public health policy. In this paper I develop an account of health security as an aversion to risky policy options. I explore three reasons for thinking risk avoidance is a distinctly worthwhile aim of public health policy: (i) that security is intrinsically valuable, (ii) that it is necessary for social planning and (iii) that it is an appropriate response to decision-making in contexts of very limited information. Striking the right balance between securing and maximizing population health thus requires a substantive, and hitherto unrecognized, value judgment. Finally, I critically evaluate the current health security agenda in light of this new account of the concept and its relationship to the other aims of public health policy. PMID:26990349

  4. High salt recruits aversive taste pathways.

    Science.gov (United States)

    Oka, Yuki; Butnaru, Matthew; von Buchholtz, Lars; Ryba, Nicholas J P; Zuker, Charles S

    2013-02-28

    In the tongue, distinct classes of taste receptor cells detect the five basic tastes; sweet, sour, bitter, sodium salt and umami. Among these qualities, bitter and sour stimuli are innately aversive, whereas sweet and umami are appetitive and generally attractive to animals. By contrast, salty taste is unique in that increasing salt concentration fundamentally transforms an innately appetitive stimulus into a powerfully aversive one. This appetitive-aversive balance helps to maintain appropriate salt consumption, and represents an important part of fluid and electrolyte homeostasis. We have shown previously that the appetitive responses to NaCl are mediated by taste receptor cells expressing the epithelial sodium channel, ENaC, but the cellular substrate for salt aversion was unknown. Here we examine the cellular and molecular basis for the rejection of high concentrations of salts. We show that high salt recruits the two primary aversive taste pathways by activating the sour- and bitter-taste-sensing cells. We also demonstrate that genetic silencing of these pathways abolishes behavioural aversion to concentrated salt, without impairing salt attraction. Notably, mice devoid of salt-aversion pathways show unimpeded, continuous attraction even to very high concentrations of NaCl. We propose that the 'co-opting' of sour and bitter neural pathways evolved as a means to ensure that high levels of salt reliably trigger robust behavioural rejection, thus preventing its potentially detrimental effects on health. PMID:23407495

  5. Risk aversion relates to cognitive ability

    DEFF Research Database (Denmark)

    Andersson, Ola; Holm, Håkan J.; Tyran, Jean-Robert Karl;

    Recent experimental studies suggest that risk aversion is negatively related to cognitive ability. In this paper we report evidence that this relation might be spurious. We recruit a large subject pool drawn from the general Danish population for our experiment. By presenting subjects with choice...... tasks that vary the bias induced by random choices, we are able to generate both negative and positive correlations between risk aversion and cognitive ability. Structural estimation allowing for heterogeneity of noise yields no significant relation between risk aversion and cognitive ability. Our...... results suggest that cognitive ability is related to random decision making rather than to risk preferences....

  6. BEHAVIOR THERAPY FOR TRANSSEXUALISM

    OpenAIRE

    Andrade, A. Chitra; Kumaraiah, V.; Mishra, H.; Chatterji, S.; Andrade, Chittaranjan

    1995-01-01

    Transsexualism is a rare disorder, and there is little literature available on its treatment. A case is presented of transsexualism with homosexual orientation in a 24 year old male. Since the disorder appeared to have behavioral antecedents, it was treated with a behavior therapy package comprising relaxation, aversion therapy with aversion relief, modelling, hypnosis, orgasmic reconditioning, behavioral counselling and sex education. Therapy resulted in normalization of gender identity, but...

  7. Small Stakes Risk Aversion in the Laboratory

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten; Ross, Don;

    all levels of wealth, or over a “sufficiently large” range of wealth. Although this second assumption if often viewed as self-evident from the vast experimental literature showing risk aversion over laboratory stakes, it actually requires that lab wealth be varied for a given subject as one takes......Evidence of risk aversion in laboratory settings over small stakes leads to a priori implausible levels of risk aversion over large stakes under certain assumptions. One core assumption in standard statements of this calibration puzzle is that individuals define utility over terminal wealth......, and that terminal wealth is defined as the sum of extra-lab wealth and any wealth accumulated in the lab. This assumption is often used in Expected Utility Theory, as well as popular alternatives such as RankDependent Utility theory. Another core assumption is that the small-stakes risk aversion is observed over...

  8. Prospective and Pavlovian mechanisms in aversive behaviour.

    Science.gov (United States)

    Rigoli, Francesco; Pezzulo, Giovanni; Dolan, Raymond J

    2016-01-01

    Studying aversive behaviour is critical for understanding negative emotions and associated psychopathologies. However a comprehensive picture of the mechanisms underlying aversion is lacking, with associative learning theories focusing on Pavlovian reactions and decision-making theoretic approaches on prospective functions. We propose a computational model of aversion that combines goal-directed and Pavlovian forms of control into a unifying framework in which their relative importance is regulated by factors such as threat distance and controllability. Using simulations, we test whether the model can reproduce available empirical findings and discuss its relevance to understanding factors underlying negative emotions such as fear and anxiety. Furthermore, the specific method used to construct the model permits a natural mapping from its components to brain structure and function. Our model provides a basis for a unifying account of aversion that can guide empirical and interventional study contexts. PMID:26539969

  9. Pests and pesticides, risk and risk aversion

    OpenAIRE

    Pannell, David J.

    1991-01-01

    Theoretical and applied literature on risk in decision making for agricultural pest control is reviewed. Risk can affect pesticide decision making either because of risk aversion or because of its influence on expected profit. It is concluded that risk does not necessarily lead to increased pesticide use by individual farmers. Uncertainty about some variables, such as pest density and pest mortality, does lead to higher optimal pesticide use under risk aversion. However, uncertainty about oth...

  10. Common Agency with Risk-Averse Agent

    OpenAIRE

    Semenov, Aggey

    2006-01-01

    I consider a common agency model under adverse selection with a risk averse agent. Contracting takes place ex ante when all players have symmetric, although incomplete, information. The coordination problem between principals leads to more distortion in the optimal policy from the first best compared to the case of risk neutrality. In contrast with the risk neutral case the principals are unable to screen completely the agent's preferences if she/he is sufficiently risk averse. However, if th...

  11. Loss Aversion, Stochastic Compensation, and Team Incentives

    OpenAIRE

    Kohei Daido; Takeshi Murooka

    2013-01-01

    We investigate moral-hazard problems with limited liability where agents have expectation-based reference-dependent preferences. We show that stochastic compensation for low performance can be optimal. Because of loss aversion, the agents have first-order risk aversion to wage uncertainty. This causes the agents to work harder when their low performance is stochastically compensated. We also examine team incentives for credibly employing such stochastic compensation. In an optimal contract, l...

  12. Risk aversion in risk acceptance criteria

    International Nuclear Information System (INIS)

    The risk averse attitude that is included in some proposed risk acceptance criteria is examined. It is shown that it is a weaker attitude than risk aversion, as is commonly defined in decision theory. Consequently, the boundary curve separating acceptable and unacceptable regions does not have to be a straight line on the logarithmic frequency-consequence space. A curve of variable slope would express the same attitude as long as the slope is less than -1

  13. Can risk aversion explain stock price volatility?

    OpenAIRE

    Stephen F. LeRoy

    2013-01-01

    Why are the prices of stocks and other assets so volatile? Efficient capital markets theory implies that stock prices should be much less volatile than actually observed, reflecting an unrealistic assumption that investors are risk neutral. If instead investors are assumed to be risk averse, predicted volatility is higher. However, models that incorporate investor avoidance of risk can explain real-world stock price volatility only under levels of risk aversion that are unrealistically high. ...

  14. Ambiguity Aversion in Models of Political Economy

    OpenAIRE

    Sophie Bade

    2013-01-01

    Four papers that use ambiguity aversion in political economy are reviewed. The first two (Bade, 2011a and 2011b) find that two important puzzles (equilibrium existence with multidimensional issue spaces and platform convergence) of the Downs-Hotelling model of electoral competition can be addressed by modeling parties as ambiguity-averse. The second two papers pertain to the Condorcet model of information aggregation. Ghirardato and Katz (2006) explains selective abstention through ambiguity ...

  15. Reference-dependent preferences and loss aversion

    Directory of Open Access Journals (Sweden)

    Einat Neuman

    2008-02-01

    Full Text Available This study employs a Discrete Choice Experiment (DCE in the health-care sector to test the loss aversion theory that is derived from reference-dependent preferences: The absolute subjective value of a deviation from a reference point is generally greater when the deviation represents a loss than when the same-sized change is perceived as a gain. As far as is known, this paper is the first to use a DCE to test the loss aversion theory. A DCE is a highly suitable tool for such testing because it estimates the marginal valuations of attributes, based onextit{ deviations from a reference point} (a constant scenario. Moreover, loss aversion can be examined for extit{each attribute separately}. Another advantage of a DCE is that is can be applied toextit{ non-traded goods with non-tangible attributes}. A health-care event is used for empirical illustration: The loss aversion theory is tested within the context of preference structures for maternity-ward attributes, estimated using data gathered from 3850 observations made by a sample of 542 women who had recently given birth. Seven hypotheses are presented and tested. Overall, significant support for behavioral loss aversion theories was found. %JEL codes: D01, D12, I19

  16. Effective return, risk aversion and drawdowns

    Science.gov (United States)

    Dacorogna, Michel M.; Gençay, Ramazan; Müller, Ulrich A.; Pictet, Olivier V.

    2001-01-01

    We derive two risk-adjusted performance measures for investors with risk averse preferences. Maximizing these measures is equivalent to maximizing the expected utility of an investor. The first measure, Xeff, is derived assuming a constant risk aversion while the second measure, Reff, is based on a stronger risk aversion to clustering of losses than of gains. The clustering of returns is captured through a multi-horizon framework. The empirical properties of Xeff, Reff are studied within the context of real-time trading models for foreign exchange rates and their properties are compared to those of more traditional measures like the annualized return, the Sharpe Ratio and the maximum drawdown. Our measures are shown to be more robust against clustering of losses and have the ability to fully characterize the dynamic behaviour of investment strategies.

  17. A comparison of risk aversion between markets

    OpenAIRE

    Tavares, José Pedro Moura

    2013-01-01

    In this study we perform a comparison between the Dow Jones Industrial Average and the FTSE 100 indexes concerning their estimated risk aversions. Risk neutral densities are calculated for both indexes using a polynomial-lognormal, a GB2 and a mixture of two lognormal distributions; we show that the best fit to observed data is obtained using the latter. For the method of best fit, and assuming a power utility function, the risk aversion of investors is calculated using a maximum likelihood m...

  18. Loss Aversion and Rent-Seeking: An Experimental Study

    OpenAIRE

    Kong, Xiaojing

    2008-01-01

    We report an experiment designed to evaluate the impact of loss aversion on rent-seeking contests. We find, as theoretically predicted, a negative relationship between rent-seeking expenditures and loss aversion. However, for any degree of loss aversion, levels of rent-seeking expenditure are higher than predicted. Moreover, we find that the effect of loss aversion becomes weaker with repetition of the contest.

  19. The Law of Demand and Risk Aversion

    OpenAIRE

    John Quah

    2002-01-01

    This note proposes a necessary and sufficient condition on a preference to guarantee that the demand function it generates satisfies the law of demand. It shows that the law of demand may be succinctly characterized by differences in an agent's level of risk aversion when she is confronted with different lotteries composed of commodity bundles.

  20. Random queues and risk averse users

    DEFF Research Database (Denmark)

    de Palma, André; Fosgerau, Mogens

    2013-01-01

    We analyze Nash equilibrium in time of use of a congested facility. Users are risk averse with general concave utility. Queues are subject to varying degrees of random sorting, ranging from strict queue priority to a completely random queue. We define the key “no residual queue” property, which...

  1. Appetitive vs. Aversive conditioning in humans.

    Science.gov (United States)

    Andreatta, Marta; Pauli, Paul

    2015-01-01

    In classical conditioning, an initially neutral stimulus (conditioned stimulus, CS) becomes associated with a biologically salient event (unconditioned stimulus, US), which might be pain (aversive conditioning) or food (appetitive conditioning). After a few associations, the CS is able to initiate either defensive or consummatory responses, respectively. Contrary to aversive conditioning, appetitive conditioning is rarely investigated in humans, although its importance for normal and pathological behaviors (e.g., obesity, addiction) is undeniable. The present study intents to translate animal findings on appetitive conditioning to humans using food as an US. Thirty-three participants were investigated between 8 and 10 am without breakfast in order to assure that they felt hungry. During two acquisition phases, one geometrical shape (avCS+) predicted an aversive US (painful electric shock), another shape (appCS+) predicted an appetitive US (chocolate or salty pretzel according to the participants' preference), and a third shape (CS-) predicted neither US. In a extinction phase, these three shapes plus a novel shape (NEW) were presented again without US delivery. Valence and arousal ratings as well as startle and skin conductance (SCR) responses were collected as learning indices. We found successful aversive and appetitive conditioning. On the one hand, the avCS+ was rated as more negative and more arousing than the CS- and induced startle potentiation and enhanced SCR. On the other hand, the appCS+ was rated more positive than the CS- and induced startle attenuation and larger SCR. In summary, we successfully confirmed animal findings in (hungry) humans by demonstrating appetitive learning and normal aversive learning. PMID:26042011

  2. Appetitive vs. Aversive Conditioning in Humans

    Directory of Open Access Journals (Sweden)

    Marta eAndreatta

    2015-05-01

    Full Text Available In classical conditioning, an initially neutral stimulus (conditioned stimulus, CS becomes associated with a biologically salient event (unconditioned stimulus, US, which might be pain (aversive conditioning or food (appetitive conditioning. After a few associations, the CS is able to initiate either defensive or consummatory responses, respectively. Contrary to aversive conditioning, appetitive conditioning is rarely investigated in humans, although its importance for normal and pathological behaviors (e.g., obesity, addiction is undeniable. The present study intents to translate animal findings on appetitive conditioning to humans using food as an US. Thirty-three participants were investigated between 8 am and 10 am without breakfast in order to assure that they felt hungry. During two acquisition phases, one geometrical shape (avCS+ predicted an aversive US (painful electric shock, another shape (appCS+ predicted an appetitive US (chocolate or salty pretzel according to the participants’ preference, and a third shape (CS- predicted neither US. In an extinction phase, these three shapes plus a novel shape (NEW were presented again without US delivery. Valence and arousal ratings as well as startle and skin conductance (SCR responses were collected as learning indices. We found successful aversive and appetitive conditioning. On the one hand, the avCS+ was rated as more negative and more arousing than the CS- and induced startle potentiation and enhanced SCR. On the other hand, the appCS+ was rated more positive than the CS- and induced startle attenuation and larger SCR. In summary, we successfully confirmed animal findings in (hungry humans by demonstrating appetitive learning and normal aversive learning

  3. Taste aversions conditioned with partial body radiation exposures

    International Nuclear Information System (INIS)

    Radiation-induced taste aversion was compared in rats which received partial body exposure to the head or abdomen with rats receiving whole body irradiation. Exposure levels ranged from 25 to 300 roentgens (R). In additional groups, saccharin aversion to partial body gamma ray exposures of the abdomen were conditioned in animals which had prior experience with the saccharin solution. Aversion was measured with a single-bottle short-term test, a 23-hour preference test and by the number of days taken to recover from the aversion. Whole-body exposure was most effective in conditioning the aversion, and exposure of the abdominal area was more effective than exposure to the head. Also, the higher the exposure, the stronger the aversion. Rats receiving prior experience with the saccharin did not condition as well as control rats with no prior saccharin experience. The possible role of radiation-induced taste aversion in human radiotherapy patients was discussed. (author)

  4. Deciding for Others Reduces Loss Aversion

    DEFF Research Database (Denmark)

    Andersson, Ola; Holm, Håkan J.; Tyran, Jean-Robert Karl;

    2014-01-01

    We study risk taking on behalf of others, both when choices involve losses and when they do not. A large-scale incentivized experiment with subjects randomly drawn from the Danish population is conducted. We find that deciding for others reduces loss aversion. When choosing between risky prospect...... others when losses loom. This finding is consistent with an interpretation of loss aversion as a bias in decision making driven by emotions and that these emotions are reduced when making decisions for others....... for which losses are ruled out by design, subjects make the same choices for themselves as for others. In contrast, when losses are possible, we find that the two types of choices differ. In particular, we find that subjects who make choices for themselves take less risk than those who decide for...

  5. Inequity aversion and the evolution of cooperation

    Science.gov (United States)

    Ahmed, Asrar; Karlapalem, Kamalakar

    2014-02-01

    Evolution of cooperation is a widely studied problem in biology, social science, economics, and artificial intelligence. Most of the existing approaches that explain cooperation rely on some notion of direct or indirect reciprocity. These reciprocity based models assume agents recognize their partner and know their previous interactions, which requires advanced cognitive abilities. In this paper we are interested in developing a model that produces cooperation without requiring any explicit memory of previous game plays. Our model is based on the notion of inequity aversion, a concept introduced within behavioral economics, whereby individuals care about payoff equality in outcomes. Here we explore the effect of using income inequality to guide partner selection and interaction. We study our model by considering both the well-mixed and the spatially structured population and present the conditions under which cooperation becomes dominant. Our results support the hypothesis that inequity aversion promotes cooperative relationship among nonkin.

  6. Different components of conditioned food aversion memory.

    Science.gov (United States)

    Nikitin, Vladimir P; Solntseva, Svetlana V; Kozyrev, Sergey A; Nikitin, Pavel V; Shevelkin, Alexey V

    2016-07-01

    Memory reconsolidation processes and protein kinase Mzeta (PKMzeta) activity in memory maintenance and reorganization are poorly understood. Therefore, we examined memory reconsolidation and PKMzeta activity during the maintenance and reorganization of a conditioned food aversion memory among snails. These processes were specifically evaluated after administration of a serotonin receptor antagonist (methiothepin), NMDA glutamate receptor antagonist (MK-801), protein synthesis inhibitor (cycloheximide; CYH), or PKMzeta inhibitor (zeta inhibitory peptide; ZIP) either 2 or 10 days after aversion training. Two days post-training, injections of MK-801 or CYH, combined with a conditioned stimulus reminder, caused amnesia development, and a second training 11 days after this induction did not lead to long-term memory formation. Interestingly, MK-801 or CYH injections and the reminder 10 days after training did not affect memory retrieval. Methiothepin and the reminder, or ZIP without the reminder, at 2 and 10 days after training led to memory impairment, while a second training 11 days after amnesia induction resulted in memory formation. These results suggest that the maintenance of a conditioned food aversion involves two different components with variable dynamics. One component could be characterized by memory strengthening over time and involve N-methyl-D-aspartate receptors and protein synthesis reconsolidation at early, but not late, training stages. The other memory component could involve serotonin-dependent reconsolidation and Mzeta-like kinase activity at both early and late stages after learning. Deficiencies within these two components led to various forms of memory impairment, which differed in terms of the formation of a conditioned food aversion during the second training. PMID:27017957

  7. Inflation Aversion and the Optimal Inflation Tax

    OpenAIRE

    Gaowang Wang; Heng-fu Zou

    2011-01-01

    The optimal inflation tax is reexamined in the framework of dynamic second best economy populated by individuals with inflation aversion. A simple formula for the optimal inflation rate is derived. Different from the literature, it is shown that if the marginal excess burden of other distorting taxes approaches zero, Friedman's rule for optimum quantity of money is not optimal, and the optimal inflation tax is negative; if the marginal excess burden of other taxes is nonzero, the optimal infl...

  8. Financial Risk Aversion and Household Asset Diversification

    OpenAIRE

    Barasinska, Nataliya; Schäfer, Dorothea; Stephan, Andreas

    2008-01-01

    This paper explores the relationship between risk attitude and asset diversification in household portfolios. We first examine the impact of manifested risk aversion on the total number of distinct assets held in a portfolio (naive diversification). The second part of the paper focuses on a more sophisticated strategy of diversification and asks whether financial theory is compatible with observed diversification patterns. Based on the German Socioeconomic Panel which provides unique measures...

  9. When does aggregation reduce uncertainty aversion?

    OpenAIRE

    Chambers, Christopher P.; Echenique, Federico

    2009-01-01

    We study the problem of uncertainty sharing within a household: "risk sharing," in a context of Knightian uncertainty. A household shares uncertain prospects using a social welfare function. We characterize the social welfare functions such that the household is collectively less averse to uncertainty than each member, and satises the Pareto principle and an independence axiom. We single out the sum of certainty equivalents as the unique member of this family which provides quasiconcave ranki...

  10. Aversive life events enhance human freezing responses.

    Science.gov (United States)

    Hagenaars, Muriel A; Stins, John F; Roelofs, Karin

    2012-02-01

    In the present study, we investigated the effect of prior aversive life events on freezing-like responses. Fifty healthy females were presented neutral, pleasant, and unpleasant images from the International Affective Picture System while standing on a stabilometric platform and wearing a polar band to assess body sway and heart rate. In the total sample, only unpleasant pictures elicited reduced body sway and reduced heart rate (freezing). Moreover, participants who had experienced 1 or more aversive life events showed greater reductions in heart rate for unpleasant versus pleasant pictures than those who had experienced no such event. In addition, relative to no-event participants, single-event participants showed reduced body sway to unpleasant pictures, while multiple-event participants showed reduced body sway in response to all picture categories. These results indicate that aversive life events affect automatic freezing responses and may indicate the cumulative effect of multiple trauma. The experimental paradigm presented is a promising method to study freezing as a primary defense response in trauma-related disorders. PMID:21767043

  11. A Moist Crevice for Word Aversion: In Semantics Not Sounds.

    Directory of Open Access Journals (Sweden)

    Paul H Thibodeau

    Full Text Available Why do people self-report an aversion to words like "moist"? The present studies represent an initial scientific exploration into the phenomenon of word aversion by investigating its prevalence and cause. Results of five experiments indicate that about 10-20% of the population is averse to the word "moist." This population often speculates that phonological properties of the word are the cause of their displeasure. However, data from the current studies point to semantic features of the word-namely, associations with disgusting bodily functions-as a more prominent source of peoples' unpleasant experience. "Moist," for averse participants, was notable for its valence and personal use, rather than imagery or arousal-a finding that was confirmed by an experiment designed to induce an aversion to the word. Analyses of individual difference measures suggest that word aversion is more prevalent among younger, more educated, and more neurotic people, and is more commonly reported by females than males.

  12. Time-varying risk aversion. An application to energy hedging

    International Nuclear Information System (INIS)

    Risk aversion is a key element of utility maximizing hedge strategies; however, it has typically been assigned an arbitrary value in the literature. This paper instead applies a GARCH-in-Mean (GARCH-M) model to estimate a time-varying measure of risk aversion that is based on the observed risk preferences of energy hedging market participants. The resulting estimates are applied to derive explicit risk aversion based optimal hedge strategies for both short and long hedgers. Out-of-sample results are also presented based on a unique approach that allows us to forecast risk aversion, thereby estimating hedge strategies that address the potential future needs of energy hedgers. We find that the risk aversion based hedges differ significantly from simpler OLS hedges. When implemented in-sample, risk aversion hedges for short hedgers outperform the OLS hedge ratio in a utility based comparison. (author)

  13. Risk Aversion and Incentive Compatibility with Ex Post Information Asymmetry

    OpenAIRE

    Hellwig, Martin

    1998-01-01

    The paper extends Diamond’s (1984) analysis of financial contracting with information asymmetry ex post and endogenous ”bankruptcy penalties” to allow for risk aversion of the borrower. The optimality of debt contracts, which Diamond obtained for the case of risk neutrality, is shown to be nonrobust to the introduction of risk aversion. This contrasts with the costly state verification literature, in which debt contracts are optimal for risk averse as well as risk neutral borrowers.

  14. Burying by rats in response to aversive and nonaversive stimuli

    OpenAIRE

    Poling, Alan; Cleary, James; Monaghan, Michael

    1981-01-01

    Previous investigations have shown that rats bury a variety of conditioned and unconditioned aversive stimuli. Such burying has been considered as a species-typical defensive reaction. In the present studies, rats buried spouts filled with Tabasco sauce, or condensed milk to which a taste aversion was conditioned, but did not bury water-filled spouts or spouts filled with a palatable novel food (apple juice) to which a taste aversion was not conditioned. However, in other experiments rats con...

  15. Risk Aversion and Expected-Utility Theory: A Calibration Theorem

    OpenAIRE

    Rabin, Matthew

    2000-01-01

    Within the expected-utility framework, the only explanation for risk aversion is that the utility function for wealth is concave: A person has lower marginal utility for additional wealth when she is wealthy than when she is poor. This paper provides a theorem showing that expected-utility theory is an utterly implausible explanation for appreciable risk aversion over modest stakes: Within expected-utility theory, for any concave utility function, even very little risk aversion over modest st...

  16. Risk Averse Members Coordination with Extended Buy-Back Contract

    OpenAIRE

    Xiaofeng Xue; Zheng Qin

    2010-01-01

    This paper considers how to coordinate a supply chain (SC) consisted of one supplier and one retailer who possess different risk aversion preference with a contract. Based on the classical buy-back contract, this paper presents an extended buy-back contract. In addition to the member’s objective of maximizing his expected profit, downside risk constraint is used to represent the SC member’s risk aversion preference. Under different risk aversion preference combination, the SC perfect solution...

  17. Spectral Risk Measures and the Choice of Risk Aversion Function

    OpenAIRE

    kevin dowd; john cotter

    2011-01-01

    Spectral risk measures are attractive risk measures as they allow the user to obtain risk measures that reflect their risk-aversion functions. To date there has been very little guidance on the choice of risk-aversion functions underlying spectral risk measures. This paper addresses this issue by examining two popular risk aversion functions, based on exponential and power utility functions respectively. We find that the former yields spectral risk measures with nice intuitive properties, but...

  18. Ambiguity Aversion and Household Portfolio Choice: Empirical Evidence

    OpenAIRE

    Stephen G. Dimmock; Roy Kouwenberg; Mitchell, Olivia S; Kim Peijnenburg

    2013-01-01

    We test the relation between ambiguity aversion and five household portfolio choice puzzles: non- participation, low allocations to equity, home-bias, own-company stock ownership, and portfolio under- diversification. In a representative U.S. household survey, we measure ambiguity aversion using custom- designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial assets in stocks, and fore...

  19. Mechanisms of radiation-induced conditioned taste aversion learning

    International Nuclear Information System (INIS)

    The literature on taste aversion learning is reviewed and discussed, with particular emphasis on those studies that have used exposure to ionizing radiation as an unconditioned stimulus to produce a conditioned taste aversion. The primary aim of the review is to attempt to define the mechanisms that lead to the initiation of the taste aversion response following exposure to ionizing radiation. Studies using drug treatments to produce a taste aversion have been included to the extent that they are relevant to understanding the mechanisms by which exposure to ionizing radiation can affect the behavior of the organism. 141 references

  20. Aversion to radiation: An ethical perspective

    International Nuclear Information System (INIS)

    Information on factors influencing risk perception will improve our understanding of people's attitude to radiation and could also play a significant role in matters of policy and decision making, especially in the management of radiation risks. One might argue that certain psychological, social and ethical values can all give rise to rational aversions to particular types of risk (i.e. reaction that are consistent and attributable to specific factors). Hence this paper will present and discuss some ethical issues that might be taken into consideration when assessing radiation risks. 11 refs

  1. Tax Aversion, Optimal Tax Rates, and Indexation

    OpenAIRE

    Roger N. Waud

    1988-01-01

    Taking account of the costs of tax evasion and avoidance activity together with the government's costs of tax enforcement it is shown that the optimal point on a stylized Laffer curve is located on the positively sloped region, not at the maximum point of the, curve. The analysis eschews the usual supply-side-type rationale for the Laffer curve and shows that such a curve can arise solely as a consequence of the optimizing tax aversion activity of a utility maximizing economic agent. The anal...

  2. Does Conspecific Fighting Yield Conditioned Taste Aversion in Rats?

    Science.gov (United States)

    Nakajima, Sadahiko; Kumazawa, Gaku; Ieki, Hayato; Hashimoto, Aya

    2012-01-01

    Running in an activity wheel yields conditioned aversion to a taste solution consumed before the running, but its underlying physiological mechanism is unknown. According to the claim that energy expenditure or general stress caused by physical exercise is a critical factor for this taste-aversion learning, not only running but also other…

  3. The Case Law on Aversive Interventions for Students with Disabilities.

    Science.gov (United States)

    Lohrmann-O'Rourke, Sharon; Zirkel, Perry A.

    1998-01-01

    This review of case law on aversive interventions for students with disabilities identifies legal boundaries and protections for students in five categories: electric shock, noxious substances, corporal punishment, restraints, and timeout. It finds that, despite the emergence of positive interventions, qualified support for aversive interventions…

  4. Dietary cravings and aversions during pregnancy.

    Science.gov (United States)

    Wijewardene, K; Fonseka, P; Goonaratne, C

    1994-01-01

    Although nausea and vomiting in early pregnancy has been studied in detail, there is little information available regarding dietary aversions and some cravings during pregnancy. To study the prevalence and factors associated with dietary aversions and cravings during pregnancy, a survey was carried out on 1000 randomly selected pregnant women attending antenatal clinics in a district in southern Sri Lanka. In this group 473 (47.3%) had pregnancy cravings for wide variety of foods: sour food 65%, unripe fruits 40%, meat and fish 47%, ripe fruits 30%, food from alms giving 26% and jam and bread fruit 22%. Ninety nine per cent of those who had pregnancy cravings had made special attempt to obtain the food of their choice and all of them had their cravings satisfied by eating the food of their choice. Pregnancy cravings was significantly higher in women who married after a love affair's than in those who had on 'arranged' marriage (p gods) than in those who were not (p < 0.05), and in women with a family income of less than Rs. 2,500 than in those with an income of more than Rs. 2,500 (p < 0.05). PMID:7774976

  5. Loss aversion and 5HTT gene variants in adolescent anxiety

    Directory of Open Access Journals (Sweden)

    Monique Ernst

    2014-04-01

    Full Text Available Loss aversion, a well-documented behavioral phenomenon, characterizes decisions under risk in adult populations. As such, loss aversion may provide a reliable measure of risky behavior. Surprisingly, little is known about loss aversion in adolescents, a group who manifests risk-taking behavior, or in anxiety disorders, which are associated with risk-avoidance. Finally, loss aversion is expected to be modulated by genotype, particularly the serotonin transporter (SERT gene variant, based on its role in anxiety and impulsivity. This genetic modulation may also differ between anxious and healthy adolescents, given their distinct propensities for risk taking. The present work examines the modulation of loss aversion, an index of risk-taking, and reaction-time to decision, an index of impulsivity, by the serotonin-transporter-gene-linked polymorphisms (5HTTLPR in healthy and clinically anxious adolescents. Findings show that loss aversion (1 does manifest in adolescents, (2 does not differ between healthy and clinically anxious participants, and (3, when stratified by SERT genotype, identifies a subset of anxious adolescents who are high SERT-expressers, and show excessively low loss-aversion and high impulsivity. This last finding may serve as preliminary evidence for 5HTTLPR as a risk factor for the development of comorbid disorders associated with risk-taking and impulsivity in clinically anxious adolescents.

  6. Coping with Loss Aversion in the Newsvendor Model

    Directory of Open Access Journals (Sweden)

    Jianwu Sun

    2015-01-01

    Full Text Available We introduce loss aversion into the decision framework of the newsvendor model. By introducing the loss aversion coefficient λ, we propose a novel utility function for the loss-averse newsvendor. First, we obtain the optimal order quantity to maximize the expected utility for the loss-averse newsvendor who is risk-neutral. It is found that this optimal order quantity is smaller than the expected profit maximization order quantity in the classical newsvendor model, which may help to explain the decision bias in the classical newsvendor model. Then, to reduce the risk which originates from the fluctuation in the market demand, we achieve the optimal order quantity to maximize CVaR about utility for the loss-averse newsvendor who is risk-averse. We find that this optimal order quantity is smaller than the optimal order quantity to maximize the expected utility above and is decreasing in the confidence level α. Further, it is proved that the expected utility under this optimal order quantity is decreasing in the confidence level α, which verifies that low risk implies low return. Finally, a numerical example is given to illustrate the obtained results and some management insights are suggested for the loss-averse newsvendor model.

  7. Impairment of aversive memory reconsolidation by localized intracranial electrical stimulation.

    Science.gov (United States)

    Stehberg, Jimmy; Levy, Dino; Zangen, Abraham

    2009-03-01

    Reconsolidation of long-term memory is blocked in animal models by macromolecular synthesis inhibitors, resulting in item-specific post-retrieval amnesia. The induction of such amnesia could ameliorate traumatic memories and phobias. However, this pharmacological approach is of limited value in humans because of toxicity. Here we report that reconsolidation of conditioned taste aversion in the rat is impaired by localized intracranial electrical stimulation. Lasting impairment was obtained only when stimulation was applied during memory reactivation and only to the dysgranular insular cortex bilaterally, which subserves the memory, but not to adjacent brain sites. The ability to learn a new association was not affected. The same method blocked new memory consolidation, but produced anterograde amnesia, reminiscent of the known effect of non-localized electroconvulsive therapy. Our results suggest that localized electrical microstimulation, such as produced by deep-brain stimulation or deep transcranial magnetic stimulation, could be used to impair long-term memory if applied during memory reactivation, and could lead to the development of a novel treatment for intractable post-traumatic stress disorder. PMID:19200060

  8. Risk Aversion Relates to Cognitive Ability: Preferences or Noise?

    DEFF Research Database (Denmark)

    Tyran, Jean-Robert Karl

    2015-01-01

    Recent experimental studies suggest that risk aversion is negatively related to cognitive ability. In this paper we report evidence that this relation might be spurious. We recruit a large subject pool drawn from the general Danish population for our experiment. By presenting subjects with choice...... tasks that vary the bias induced by random choices, we are able to generate both negative and positive correlations between risk aversion and cognitive ability. Structural estimation allowing for heterogeneity of noise yields no significant relation between risk aversion and cognitive ability. Our...... results suggest that cognitive ability is related to random decision making, rather than to risk preferences....

  9. Buyback Contract Coordinating Supply Chain Incorporated Risk Aversion

    Directory of Open Access Journals (Sweden)

    Guangxing

    2013-02-01

    Full Text Available This research studies the buyback contract of a supply chain system composed of a risk-neutral supplier and a risk-averse retailer. The buyback contract is divided into two cases, the credit for all unsold goods and the credit for a partial return of goods, which are theoretically analyzed and simulated numerically respectively. The results show that when the retailer is risk averse, the supply chain system is able to achieve coordination. The buyback price is an increasing function of and the buyback ratio is also an increasing function of, while the wholesale price is a decreasing function of the risk aversion.

  10. Risk-Aversion and Prudence in Rent-Seeking Games

    OpenAIRE

    Treich, Nicolas

    2009-01-01

    This paper considers a common n-agent symmetric rent-seeking game. It derives conditions so that risk-aversion and risk always decrease rent-seeking efforts. These conditions hold for any regular contest success function when risk-averse rent-seekers are also prudent. Under n = 2, prudence is a necessary and sufficient condition for risk-aversion to decrease rent-seeking efforts compared to risk-neutrality. An intuition for this result is given based on a self-protection model.

  11. Conditioned taste aversions and specific need states in the rat

    International Nuclear Information System (INIS)

    Rats were allowed to consume either sucrose or saline prior to being made ill by injection of either insulin or formalin, or by exposure to x rays. A 2-bottle preference test between sucrose and saline revealed that formalin was an effective agent in conditioning aversions to sucrose but not to saline. Similarly, injections of insulin were found to be effective in producing conditioned aversions to saline but not to sucrose. X irradiation produced strong aversions to either solution. The results are discussed with regard to the specific need states that insulin and formalin produce. (U.S.)

  12. Amygdala signals subjective appetitiveness and aversiveness of mixed gambles

    DEFF Research Database (Denmark)

    Gelskov, Sofie V.; Henningsson, Susanne; Madsen, Kristoffer Hougaard;

    2015-01-01

    People are more sensitive to losses than to equivalent gains when making financial decisions. We used functional magnetic resonance imaging (fMRI) to illuminate how the amygdala contributes to loss aversion. The blood oxygen level dependent (BOLD) response of the amygdala was mapped while healthy...... and rejected gambles with equal probability. Amygdala activity increased the more the gain-loss ratio deviated from the individual decision boundary showing that the amygdala codes action value. This response pattern was more strongly expressed in loss aversive individuals, linking amygdala activity...... with individual differences in loss aversion. Together, the results show that the amygdala signals subjective appetitiveness or aversiveness of gain-loss ratios at the time of choice. (C) 2015 Elsevier Ltd. All rights reserved....

  13. Risk Aversion and Engagement in the Sharing Economy

    Directory of Open Access Journals (Sweden)

    Jessica Santana

    2015-10-01

    Full Text Available The sharing economy is a new online community that has important implications for offline behavior. This study evaluates whether engagement in the sharing economy is associated with an actor’s aversion to risk. Using a web-based survey and a field experiment, we apply an adaptation of Holt and Laury’s (2002 risk lottery game to a representative sample of sharing economy participants. We find that frequency of activity in the sharing economy predicts risk aversion, but only in interaction with satisfaction. While greater satisfaction with sharing economy websites is associated with a decrease in risk aversion, greater frequency of usage is associated with greater risk aversion. This analysis shows the limitations of a static perspective on how risk attitudes relate to participation in the sharing economy.

  14. Myopic loss aversion: Potential causes of replication failures

    Directory of Open Access Journals (Sweden)

    Alexander Klos

    2013-09-01

    Full Text Available This paper presents two studies on narrow bracketing and myopic loss aversion. The first study shows that the tendency to segregate multiple gambles is eliminated if subjects face a certainty equivalent or a probability equivalent task instead of a binary choice. The second study argues that the behavioral differences previously attributed entirely to myopic loss aversion are partly because long-term return properties are simply easier to grasp if the return information is already provided in the form of long-term returns rather than one-year returns. Both results may be related to recent failures to replicate myopic loss aversion. When the choice situation is structured in such a way that it draws respondents' attention to the final outcome distribution and/or if severe misestimations of long-term returns based on short-term return information are unlikely, behavioral differences consistent with myopic loss aversion are less likely to be observed.

  15. OPTIMAL POST-HARVEST GRAINS STORAGE BY RISK AVERSE FARMERS

    OpenAIRE

    Lai, Jing-Yi; Myers, Robert J.; Hanson, Steven D.

    2001-01-01

    Most previous research on post-harvest grain storage by farmers has assumed risk-neutral behavior and/or made restrictive assumptions about underlying price probability distributions. In this study we solve the optimal post-harvest storage problem for a risk averse farmer under more general assumptions about underlying price distributions. The resulting model is applied to Michigan corn farmers and results show that, contrary to the sell all-or-nothing risk-neutral rule, risk averse farmers w...

  16. Expectation-Based Loss Aversion and Strategic Interaction

    OpenAIRE

    Simon Dato; Andreas Grunewald; Daniel Müller

    2015-01-01

    This paper provides a comprehensive analysis regarding strategic interaction under expectation-based loss-aversion. First, we develop a coherent framework for the analysis by extending the equilibrium concepts of Koszegi and Rabin (2006, 2007) to strategic interaction and demonstrate how to derive equilibria. Second, we delineate how expectation-based loss-averse players differ in their strategic behavior from their counterparts with standard expected-utility preferences. Third, we analyze eq...

  17. Loss Aversion, Team Relocations, and Major League Expansion

    OpenAIRE

    Humphreys, Brad; Zhou, Li

    2014-01-01

    Professional sports teams receive large public subsidies for new facility construction. Empirical research suggests that these subsidies cannot be justified by tangible or intangible economic benefits. We develop a model of bargaining between local governments and teams over subsidies that includes league expansion decisions. The model features loss aversion by fans that captures lost utility when a team leaves a city. The model predicts that teams exploit this loss aversion to extract larger...

  18. Peer Pressure in Work Teams : The effects of Inequity Aversion

    OpenAIRE

    Masclet, David

    2002-01-01

    Working Paper du GATE 2002-15 Many empirical studies have shed light on the efficiency of peer pressure. I propose here to model peer pressure by incorporating in the utility function self centered inequity aversion. I find that opportunity for sufficiently inequity averse players to punish their peers, is effective in inducing others to cooperate. At the equilibrium, all players cooperate and punish any shirker since punishing is a way to reduce inequity. Contrary, nobody cooperates witho...

  19. Risk Aversion and Herd Behavior in Financial Markets

    OpenAIRE

    Décamps, Jean-Paul; Lovo, Stefano

    2003-01-01

    We show that differences in investors risk aversion can generate herd behavior in stock markets where assets are traded sequentially. This in turn prevents markets from being efficient in the sense that financial market prices do not converge to the asset's fundamental value. The informational efficiency of the market depends on the distribution of the risky asset across risk averse agents. These results are obtained without introducing multidimensional uncertainty.

  20. Negative Voters: Electoral Competition with Loss-Aversion

    OpenAIRE

    Ben Lockwood; James Rockey

    2015-01-01

    This paper studies how voter loss-aversion affects electoral competition in a Downsian setting. Assuming that voters’ reference point is the status quo, we show that loss-aversion has a number of effects. First, there is policy rigidity both parties choose platforms equal to the status quo, regardless of other parameters. Second, that there is a moderation effect when there is policy rigidity, the equilibrium policy outcome is closer to the moderate voters’ ideal point than in the absence of ...

  1. Ambiguity Aversion and Household Portfolio Choice Puzzles: Empirical Evidence

    OpenAIRE

    Dimmock, Stephen; Kouwenberg, Roy; Mitchell, Olivia; Peijnenburg, Kim

    2016-01-01

    markdownabstractWe test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambiguity preferences using custom-designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial a...

  2. Gender bias in risk aversion: evidence from multiple choice exams

    OpenAIRE

    Marín, Carmen; Rosa-García, Alfonso

    2011-01-01

    We provide evidence on a gender bias in risk aversion among students of economics in Spain. In a sample of 1947 multiple choice exams with penalization for errors, we find that women consistently answer less questions, while differences in marks are not significant. These empirical results are consistent with a recent theoretical prediction of the effect of risk aversion in test exams. This finding shows that women can suffer a disadvantage with this kind of exams widely used in education.

  3. Risk-Averse Control of Undiscounted Transient Markov Models

    CERN Document Server

    Cavus, Ozlem

    2012-01-01

    We use Markov risk measures to formulate a risk-averse version of the undiscounted total cost problem for a transient controlled Markov process. We derive risk-averse dynamic programming equations and we show that a randomized policy may be strictly better than deterministic policies, when risk measures are employed. We illustrate the results on an optimal stopping problem and an organ transplant problem.

  4. Imagery rescripting: Is incorporation of the most aversive scenes necessary?

    Science.gov (United States)

    Dibbets, Pauline; Arntz, Arnoud

    2016-05-01

    During imagery rescripting (ImRs) an aversive memory is relived and transformed to have a more positive outcome. ImRs is frequently applied in psychological treatment and is known to reduce intrusions and distress of the memory. However, little is known about the necessity to incorporate the central aversive parts of the memory in ImRs. To examine this necessity one hundred participants watched an aversive film and were subsequently randomly assigned to one of four experimental conditions: ImRs including the aversive scenes (Late ImRs), ImRs without the aversive scenes (Early ImRs), imaginal exposure (IE) or a control condition (Cont). Participants in the IE intervention reported the highest distress levels during the intervention; Cont resulted in the lowest levels of self-reported distress. For the intrusion frequency, only the late ImRs resulted in fewer intrusions compared to the Cont condition; Early ImRs produced significantly more intrusions than the Late ImRs or IE condition. Finally, the intrusions of the Late ImRs condition were reported as less vivid compared to the other conditions. To conclude, it seems beneficial including aversive scenes in ImRs after an analogue trauma induction. PMID:26076101

  5. Neurocognitive development of risk aversion from early childhood to adulthood

    Directory of Open Access Journals (Sweden)

    David ePaulsen

    2012-01-01

    Full Text Available Human adults tend to avoid risk. In behavioral economic studies, risk aversion is manifest as a preference for sure gains over uncertain gains. However, children tend to be less averse to risk than adults. Given that many of the brain regions supporting decision making under risk do not reach maturity until late adolescence or beyond it is possible that mature risk-averse behavior may emerge from the development of decision-making circuitry. To explore this hypothesis, we tested 6- to 8-year-old children, 14- to 16-year-old adolescents, and young adults in a risky-decision task during functional magnetic resonance imaging (fMRI data acquisition. We found a number of decision-related brain regions to increase in activation with age during decision making, including areas associated with contextual memory retrieval and the incorporation of prior outcomes into the current decision-making strategy, e.g. insula, hippocampus and amygdala. Further, children who were more risk averse showed increased activation during decision making in vmPFC and ventral striatum. Our findings indicate that the emergence of adult levels of risk aversion co-occurs with the recruitment of regions supporting decision making under risk, including the integration of prior outcomes into current decision-making behavior. This pattern of results suggests that individual differences in the development of risk aversion may reflect differences in the maturation of these neural processes.

  6. Fractional-moment CAPM with loss aversion

    International Nuclear Information System (INIS)

    In this paper, we present a new fractional-order value function which generalizes the value function of Kahneman and Tversky [Kahneman D, Tversky A. Prospect theory: an analysis of decision under risk. Econometrica 1979;47:263-91; Tversky A, Kahneman D. Advances in prospect theory: cumulative representation of uncertainty. J. Risk Uncertainty 1992;4:297-323], and give the corresponding fractional-moment versions of CAPM in the cases of both the prospect theory [Kahneman D, Tversky A. Prospect theory: an analysis of decision under risk. Econometrica 1979;47:263-91; Tversky A, Kahneman D. Advances in prospect theory: cumulative representation of uncertainty. J. Risk Uncertainty 1992;4:297-323] and the expected utility model. The models that we obtain can be used to price assets when asset return distributions are likely to be asymmetric stable Levy distribution during panics and stampedes in worldwide security markets in 2008. In particular, from the prospect theory we get the following fractional-moment CAPM with loss aversion: E(Ri-R0)=(E[(W-W0)+-0.12(Ri-R0)]+2.25E[(W0-W)+-0.12(Ri-R0)])/ (E[(W-W0)+-0.12 (W-R0)]+2.25E[(W0-W)+-0.12(W-R0)]) .E(W-R0), where W0 is a fixed reference point distinguishing between losses and gains.

  7. Aversion norm, replacing in the poem siab

    Directory of Open Access Journals (Sweden)

    Ebrahim Namdari

    2014-03-01

    Full Text Available Aversion norm or DE familiarization is a term that formalists it was first introduced. They believe that the work of art, not automatic and amazing things to see is that, because of things after a while, replication of us are normal, so do not see it. We poetic language, we are faced with a fundamental change in the relationship between signifier and signified, i.e. Familiar language, signifiers, signified by certain, but the poetic language signifier, the signified can be found in the pelvis, and the audience to understand the signified a new, hard falls, and the longer perceived to be, and where it refers to the discovery, after some hesitation, more enjoyable, the audience will have a special effect. 's poetic language, the beauty side implicated in emotional and motivational speaking, hiding the core meaning of the word, and indeed with the usual meaning and familiar DE familiarization, are shown. Beauty in ordinary language, they do not see, thus implying that subtle poet highlighting the special meaning of the word in ordinary language is different, the vocabulary word meanings change, and where it is meant to transform Familiar word, because the audience is emotionally motivated, it is more effective. The poet does not read words into their common name, but it so describes it as if for the first time we've seen. Word to describe him, sometimes uses the common name of its components, and metonymy create, and sometimes it does not use the common name of its components, but another word to call it, uses, and in fact the word it brings a different metaphor, and thus far is the common standard language, new language makes.

  8. Fractional-moment CAPM with loss aversion

    Energy Technology Data Exchange (ETDEWEB)

    Wu Yahao [Dep. of Math., South China University of Technology, Guangzhou 510640 (China); Wang Xiaotian [Dep. of Math., South China University of Technology, Guangzhou 510640 (China)], E-mail: swa001@126.com; Wu Min [Dep. of Math., South China University of Technology, Guangzhou 510640 (China)

    2009-11-15

    In this paper, we present a new fractional-order value function which generalizes the value function of Kahneman and Tversky [Kahneman D, Tversky A. Prospect theory: an analysis of decision under risk. Econometrica 1979;47:263-91; Tversky A, Kahneman D. Advances in prospect theory: cumulative representation of uncertainty. J. Risk Uncertainty 1992;4:297-323], and give the corresponding fractional-moment versions of CAPM in the cases of both the prospect theory [Kahneman D, Tversky A. Prospect theory: an analysis of decision under risk. Econometrica 1979;47:263-91; Tversky A, Kahneman D. Advances in prospect theory: cumulative representation of uncertainty. J. Risk Uncertainty 1992;4:297-323] and the expected utility model. The models that we obtain can be used to price assets when asset return distributions are likely to be asymmetric stable Levy distribution during panics and stampedes in worldwide security markets in 2008. In particular, from the prospect theory we get the following fractional-moment CAPM with loss aversion: E(R{sub i}-R{sub 0})=(E[(W-W{sub 0}){sub +}{sup -0.12}(R{sub i}-R{sub 0})]+2.25E[(W{sub 0}-W){sub +}{sup -0.12}(R{sub i}-R{sub 0})])/ (E[(W-W{sub 0}){sub +}{sup -0.12} (W-R{sub 0})]+2.25E[(W{sub 0}-W){sub +}{sup -0.12}(W-R{sub 0})]) .E(W-R{sub 0}), where W{sub 0} is a fixed reference point distinguishing between losses and gains.

  9. Risk-Averse Newsvendor Model with Strategic Consumer Behavior

    Directory of Open Access Journals (Sweden)

    Tie Wang

    2013-01-01

    Full Text Available The classic newsvendor problem focuses on maximizing the expected profit or minimizing the expected cost when the newsvendor faces myopic customers. However, it ignores the customer’s bargain-hunting behavior and risk preference measure of the newsvendor. As a result, we carry out the rational expectation (RE equilibrium analysis for risk-averse newsvendor facing forward-looking customers who anticipate future sales and choose purchasing timing to maximize their expected surplus. We propose the equations satisfied by the RE equilibrium price and quantity for the risk-averse retailer in general setting and the explicit equilibrium decisions for the case where demand follows the uniform distribution and utility is a general power function. We identify the impacts of the system parameters on the RE equilibrium for this specific situation. In particular, we show that the RE equilibrium price for some risk-averse newsvendors is lower than for a risk-neutral retailer and the RE equilibrium stocking quantity for some risk-averse newsvendors is higher than for a risk-neutral retailer. We also find that the RE equilibrium sale price for a risk-averse newsvendor is decreasing in salvage price in some situations.

  10. Mangifera indica L. extract (Vimang improves the aversive memory in spinocerebellar ataxia type 2 transgenic mice.

    Directory of Open Access Journals (Sweden)

    Natasha Maurmann

    2014-06-01

    Full Text Available Context: The spinocerebellar ataxia type 2 (SCA-2 is a progressive neurodegenerative disorder without specific therapy identified, and it is related to the loss of function in the cerebellum, mitochondrial dysfunction, oxidative stress and neurotoxic processes. Scientific evidence indicates that Mangifera indica L. aqueous extract (MiE and its major constituent (mangiferin display antioxidant, anti-inflammatory and neuroprotective actions. Aims: To investigate the MiE and mangiferin effects on behavioral outcomes of neurological function in SCA-2 transgenic mice. Methods: The SCA-2 transgenic mice were daily and orally administered during 12 months with MiE (10, 50, and 100 mg/kg, mangiferin (10 mg/kg or vehicle. It was evaluated locomotion (open-field, aversive memory (inhibitory avoidance and declarative memory (object recognition. To explore possible cellular mechanisms underlying the in vivo effects was also evaluated their effects on nerve grow factor (NGF and tumor necrosis factor-α (TNF-α levels in the human glioblastoma cell line U138-MG supernatant. Results: MiE administration did not affect the object recognition memory, but mangiferin did. The natural extract improved selectively the aversive memory in SCA-2 mice, indicating that MiE can affect behavioral parameters regarding fear-related memory. MiE also induced a significant increase in supernatant levels of NGF and TNF-α in vitro in human U138-MG glioblastoma cells. Conclusions: The results suggest that MiE enhances the aversive memory through a mechanism that might involve an increase in neurotrophin and cytokine levels. These findings constitute the basis for the use of the natural extract in the prevention/treatment of memory deficits in SCA-2.

  11. Gender Differences in Risk Aversion Among Chinese University Students.

    Science.gov (United States)

    Lam, Desmond

    2015-12-01

    This paper examines gender differences in risk aversion among Chinese university students. Chinese females are proposed to be more risk averse and require a higher risk premium when faced with a gamble option in the gain-domain frame as compared to Chinese males. Two groups of 100 participants each (male = 100 and female = 100 in total) were recruited to fill up questionnaires that included items relating to objective probability lotteries. Within each group, it was found that Chinese males and females did not differ in their risk aversion. However, results show that Chinese males tend to react more readily to rising risk premium by taking up options with higher expected values when compared to Chinese females. Current findings will have useful implications to marketers (particularly, promoters of gambling products) and problem gambling counselors. PMID:25112219

  12. Use of risk aversion in risk acceptance criteria

    International Nuclear Information System (INIS)

    Quantitative risk acceptance criteria for technological systems must be both justifiable, based upon societal values and objectives, and workable in the sense that compliance is possible and can be demonstrated in a straightforward manner. Societal values have frequently been assessed using recorded accident statistics on a wide range of human activities assuming that the statistics in some way reflect societal preferences, or by psychometric surveys concerning perceptions and evaluations of risk. Both methods indicate a societal aversion to risk e.g., many small accidents killing a total of 100 people are preferred over one large accident in which 100 lives are lost. Some of the implications of incorporating risk aversion in acceptance criteria are discussed. Calculated risks of various technological systems are converted to expected social costs using various risk aversion factors. The uncertainties in these assessments are also discussed

  13. Proust revisited: odours as triggers of aversive memories.

    Science.gov (United States)

    Toffolo, Marieke B J; Smeets, Monique A M; van den Hout, Marcel A

    2012-01-01

    According to the Proust phenomenon, olfactory memory triggers are more evocative than other-modality triggers resulting in more emotional and detailed memories. An experimental paradigm was used to investigate this in aversive memories, similar to those experienced by patients with posttraumatic stress disorder. Seventy healthy participants watched an aversive film, while simultaneously being exposed to olfactory, auditory and visual triggers, which were matched on intensity, valence, arousal and salience. During a second session one week later, participants were randomly exposed to one of the three triggers, and asked to think back about the film and to rate the resulting memory. Results revealed that odour-evoked memories of aversive events were more detailed, unpleasant and arousing than memories evoked by auditory, but not visual, triggers. PMID:21547759

  14. Human capital and risk aversion in relational incentive contracts

    International Nuclear Information System (INIS)

    This paper examines a self-enforced relational incentive contract between a risk neutral principal and a risk averse agent where the agent's human capital is essential in ex post realization of values. I analyse the effect of outside options on the optimal bonus level, showing how the presence of ex post outside options may impede desirable degrees of performance pay. The effect of risk aversion and incentive responsiveness is analysed by allowing for linear contracts. I show that the first order effect of these parameters are the same as in verifiable contracts, but second order effects show that the optimal bonus level's sensitivity to risk aversion and incentive responsiveness increases with the discount factor. The analysis has interesting implications on firm boundaries and specificity choices. (author)

  15. Risk Aversion and Engagement in the Sharing Economy

    OpenAIRE

    Jessica Santana; Paolo Parigi

    2015-01-01

    The sharing economy is a new online community that has important implications for offline behavior. This study evaluates whether engagement in the sharing economy is associated with an actor’s aversion to risk. Using a web-based survey and a field experiment, we apply an adaptation of Holt and Laury’s (2002) risk lottery game to a representative sample of sharing economy participants. We find that frequency of activity in the sharing economy predicts risk aversion, but only in interaction wit...

  16. Risk Aversion Relates to Cognitive Ability: Preferences or Noise?

    DEFF Research Database (Denmark)

    Andersson, Ola; Holm, Håkan J.; Tyran, Jean-Robert Karl;

    2016-01-01

    Recent experimental studies suggest that risk aversion is negatively related to cognitive ability. In this paper we report evidence that this relation may be spurious. We recruit a large subject pool drawn from the general Danish population for our experiment. By presenting subjects with choice...... tasks that vary the bias induced by random choices, we are able to generate both negative and positive correlations between risk aversion and cognitive ability. Our results suggest that cognitive ability is related to random decision making rather than to risk preferences....

  17. On Loss Aversion, Level-1 Reasoning, and Betting

    DEFF Research Database (Denmark)

    Erev, Ido; Gilat-Yihyie, Sharon; Marchiori, Davide;

    2014-01-01

    Previous research suggests that human reaction to risky opportunities reflects two contradicting biases: “loss aversion”, and “limited level of reasoning” that leads to overconfidence. Rejection of attractive gambles is explained by loss aversion, while counterproductive risk seeking is attributed...... to limited level of reasoning. The current research highlights a shortcoming of this popular (but often implicit) “contradicting biases” assertion. Studies of “negative-sum betting games” reveal high rate of counterproductive betting even when limited level of reasoning and loss aversion imply no...

  18. Loss Aversion and Time-Differentiated Electricity Pricing

    Energy Technology Data Exchange (ETDEWEB)

    Spurlock, C. Anna [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-06-01

    I develop a model of loss aversion over electricity expenditure, from which I derive testable predictions for household electricity consumption while on combination time-of-use (TOU) and critical peak pricing (CPP) plans. Testing these predictions results in evidence consistent with loss aversion: (1) spillover effects - positive expenditure shocks resulted in significantly more peak consumption reduction for several weeks thereafter; and (2) clustering - disproportionate probability of consuming such that expenditure would be equal between the TOUCPP or standard flat-rate pricing structures. This behavior is inconsistent with a purely neoclassical utility model, and has important implications for application of time-differentiated electricity pricing.

  19. Uncertain Demand, Consumer Loss Aversion, and Flat-Rate Tariffs

    OpenAIRE

    Herweg, Fabian; Mierendorff, Konrad

    2011-01-01

    We consider a model of firm pricing and consumer choice, where consumers are loss averse and uncertain about their future demand. Possibly, consumers in our model prefer a flat rate to a measured tariff, even though this choice does not minimize their expected billing amount - a behavior in line with ample empirical evidence. We solve for the profit-maximizing two-part tariff, which is a flat rate if (a) marginal costs are not too high, (b) loss aversion is intense, and (c) there are strong v...

  20. AN ANALYSIS OF THE RISK AVERSION OF FARM OPERATORS: AN ASSET PORTFOLIO APPROACH

    OpenAIRE

    Lins, David A.; Gabriel, Stephen C.; Sonka, Steven T.

    1981-01-01

    The absolute and relative risk aversion characteristics of a large sample of farm operators were estimated from the observed portfolio responses to changes in wealth. Regression estimates suggest that farm operators display decreasing absolute risk aversion. Relative risk aversion varies by type of farm. However, the definition of risky assets has an important bearing on relative risk aversion characteristics. Non-wealth variables are also important in explaining the holding of risky assets b...

  1. A Survey Data Response to the Teaching of Utility Curves and Risk Aversion

    Science.gov (United States)

    Hobbs, Jeffrey; Sharma, Vivek

    2011-01-01

    In many finance and economics courses as well as in practice, the concept of risk aversion is reduced to the standard deviation of returns, whereby risk-averse investors prefer to minimize their portfolios' standard deviations. In reality, the concept of risk aversion is richer and more interesting than this, and can easily be conveyed through…

  2. Onset and Offset of Aversive Events Establish Distinct Memories Requiring Fear and Reward Networks

    Science.gov (United States)

    Andreatta, Marta; Fendt, Markus; Muhlberger, Andreas; Wieser, Matthias J.; Imobersteg, Stefan; Yarali, Ayse; Gerber, Bertram; Pauli, Paul

    2012-01-01

    Two things are worth remembering about an aversive event: What made it happen? What made it cease? If a stimulus precedes an aversive event, it becomes a signal for threat and will later elicit behavior indicating conditioned fear. However, if the stimulus is presented upon cessation of the aversive event, it elicits behavior indicating…

  3. What can behavior analysis learn from the aversives controversy?

    OpenAIRE

    Johnston, J. M.

    1991-01-01

    The paper argues that behavior analysis may have contributed to the aversives controversy in a number of ways. The role that the field has played and the lessons that may be learned are discussed in the areas of research, training, and politics.

  4. Subjective Expected Utility with Non-Increasing Risk Aversion

    NARCIS (Netherlands)

    P.P. Wakker (Peter)

    1989-01-01

    textabstractIt is shown that assumptions about risk aversion, usually studied under the pre-supposition of expected utility maximization, have a surprising extra merit at an earlier stage of the measurement work: together with the sure-thing principle, these assumptions imply subjective expected uti

  5. Cannabinoid conditioned reward and aversion: behavioral and neural processes.

    Science.gov (United States)

    Murray, Jennifer E; Bevins, Rick A

    2010-03-10

    The discovery that delta-9-tetrahydrocannabinol (Δ(9)-THC) is the primary psychoactive ingredient in marijuana prompted research that helped elucidate the endogenous cannabinoid system of the brain. Δ(9)-THC and other cannabinoid ligands with agonist action (CP 55,940, HU210, and WIN 55,212-2) increase firing of dopamine neurons and increase synaptic dopamine in brain regions associated with reward and drug addiction. Such changes in cellular processes have prompted investigators to examine the conditioned rewarding effects of the cannabinoid ligands using the place conditioning task with rats and mice. As reviewed here, these cannabinoid ligands can condition place preferences (evidence for rewarding effects) and place aversions (evidence for aversive qualities). Notably, the procedural details used in these place conditioning studies have varied across laboratories. Such variation includes differences in apparatus type, existence of procedural biases, dose, number of conditioning trials, injection-to-placement intervals, and pre-training drug exposure. Some differences in outcome across studies can be explained by these procedural variables. For example, low doses of Δ(9)-THC appear to have conditioned rewarding effects, whereas higher doses have aversive effects that either mask these rewarding effects or condition a place aversion. Throughout this review we highlight key areas that need further research. PMID:20495676

  6. How not to extend models of inequality aversion

    Czech Academy of Sciences Publication Activity Database

    Engelmann, Dirk

    2012-01-01

    Roč. 81, č. 2 (2012), s. 599-605. ISSN 0167-2681 Institutional research plan: CEZ:AV0Z70850503 Keywords : inequality aversion * efficiency * social preferences Subject RIV: AH - Economics Impact factor: 1.065, year: 2012

  7. The risk-averse newsvendor problem with random capacity

    NARCIS (Netherlands)

    Wu, Meng; Zhu, Stuart X.; Teunter, Ruud H.

    2013-01-01

    We study the effect of capacity uncertainty on the inventory decisions of a risk-averse newsvendor. We consider two well-known risk criteria, namely Value-at-Risk (VaR) included as a constraint and Conditional Value-at-Risk (CVaR). For the risk-neutral newsvendor, we find that the optimal order quan

  8. Inequality aversion, efficiency, and maximin preferences in simple distribution experiments

    Czech Academy of Sciences Publication Activity Database

    Engelmann, Dirk; Strobel, M.

    2004-01-01

    Roč. 94, č. 4 (2004), s. 857-869. ISSN 0002-8282 Institutional research plan: CEZ:AV0Z7085904 Keywords : simple distribution experiments * inequality aversion , efficiency and maximin preferences Subject RIV: AH - Economics Impact factor: 1.655, year: 2004

  9. Overcoming Learning Aversion in Evaluating and Managing Uncertain Risks.

    Science.gov (United States)

    Cox, Louis Anthony Tony

    2015-10-01

    Decision biases can distort cost-benefit evaluations of uncertain risks, leading to risk management policy decisions with predictably high retrospective regret. We argue that well-documented decision biases encourage learning aversion, or predictably suboptimal learning and premature decision making in the face of high uncertainty about the costs, risks, and benefits of proposed changes. Biases such as narrow framing, overconfidence, confirmation bias, optimism bias, ambiguity aversion, and hyperbolic discounting of the immediate costs and delayed benefits of learning, contribute to deficient individual and group learning, avoidance of information seeking, underestimation of the value of further information, and hence needlessly inaccurate risk-cost-benefit estimates and suboptimal risk management decisions. In practice, such biases can create predictable regret in selection of potential risk-reducing regulations. Low-regret learning strategies based on computational reinforcement learning models can potentially overcome some of these suboptimal decision processes by replacing aversion to uncertain probabilities with actions calculated to balance exploration (deliberate experimentation and uncertainty reduction) and exploitation (taking actions to maximize the sum of expected immediate reward, expected discounted future reward, and value of information). We discuss the proposed framework for understanding and overcoming learning aversion and for implementing low-regret learning strategies using regulation of air pollutants with uncertain health effects as an example. PMID:26491992

  10. Reappraising social insect behavior through aversive responsiveness and learning.

    Directory of Open Access Journals (Sweden)

    Edith Roussel

    Full Text Available BACKGROUND: The success of social insects can be in part attributed to their division of labor, which has been explained by a response threshold model. This model posits that individuals differ in their response thresholds to task-associated stimuli, so that individuals with lower thresholds specialize in this task. This model is at odds with findings on honeybee behavior as nectar and pollen foragers exhibit different responsiveness to sucrose, with nectar foragers having higher response thresholds to sucrose concentration. Moreover, it has been suggested that sucrose responsiveness correlates with responsiveness to most if not all other stimuli. If this is the case, explaining task specialization and the origins of division of labor on the basis of differences in response thresholds is difficult. METHODOLOGY: To compare responsiveness to stimuli presenting clear-cut differences in hedonic value and behavioral contexts, we measured appetitive and aversive responsiveness in the same bees in the laboratory. We quantified proboscis extension responses to increasing sucrose concentrations and sting extension responses to electric shocks of increasing voltage. We analyzed the relationship between aversive responsiveness and aversive olfactory conditioning of the sting extension reflex, and determined how this relationship relates to division of labor. PRINCIPAL FINDINGS: Sucrose and shock responsiveness measured in the same bees did not correlate, thus suggesting that they correspond to independent behavioral syndromes, a foraging and a defensive one. Bees which were more responsive to shock learned and memorized better aversive associations. Finally, guards were less responsive than nectar foragers to electric shocks, exhibiting higher tolerance to low voltage shocks. Consequently, foragers, which are more sensitive, were the ones learning and memorizing better in aversive conditioning. CONCLUSIONS: Our results constitute the first integrative

  11. Interactions between radiation and amphetamine in taste aversion learning and the role of the area postrema in amphetamine-induced conditioned taste aversions

    International Nuclear Information System (INIS)

    Three experiments were run to assess the role of the area postrema in taste aversion learning resulting from combined treatment with subthreshold unconditioned stimuli and in the acquisition of an amphetamine-induced taste aversion. In the first experiment, it was shown that combined treatment with subthreshold radiation (15 rad) and subthreshold amphetamine (0.5 mg/kg, IP) resulted in the acquisition of a taste aversion. The second experiment showed that lesions of the area postrema blocked taste aversion learning produced by two subthreshold doses of amphetamine. In the third experiment, which looked at the dose-response curve for amphetamine-induced taste aversion learning in intact rats and rats with area postrema lesions, it was shown that both groups of rats acquired taste aversions following injection of amphetamine, although the rats with lesions showed a less severe aversion than the intact rats. The results are interpreted as indicating that amphetamine-induced taste aversion learning may involve area postrema-mediated mechanisms, particularly at the lower doses, but that an intact area postrema is not a necessary condition for the acquisition of an amphetamine-induced taste aversion

  12. Loss-Averse Retailer’s Optimal Ordering Policies for Perishable Products with Customer Returns

    Directory of Open Access Journals (Sweden)

    Xu Chen

    2014-01-01

    Full Text Available We investigate the loss-averse retailer’s ordering policies for perishable product with customer returns. With the introduction of the segmental loss utility function, we depict the retailer’s loss aversion decision bias and establish the loss-averse retailer’s ordering policy model. We derive that the loss-averse retailer’s optimal order quantity with customer returns exists and is unique. By comparison, we obtain that both the risk-neutral and the loss-averse retailer’s optimal order quantities depend on the inventory holding cost and the marginal shortage cost. Through the sensitivity analysis, we also discuss the effect of loss-averse coefficient and the ratio of return on the loss-averse retailer’s optimal order quantity with customer returns.

  13. Chemosensory alterations and cancer therapies

    International Nuclear Information System (INIS)

    Taste and olfaction provide sensory information and sensory pleasure. Cancer therapies affect both. Chemotherapy has not been shown to produce dramatic losses of taste or smell, but systematic studies on various chemotherapeutic agents and types of cancer are lacking. Radiation therapy does produce clear losses of both taste and smell. Both chemotherapy and radiation therapy alter the pleasure produced by taste and smell through the formation of conditioned aversions. That is, foods consumed in proximity with the nausea of therapy come to be unpleasant. The impact of conditioned aversions can be diminished by providing a scapegoat food just before therapy. Alterations in foods may be beneficial to the cancer patient. Increasing the concentrations of flavor ingredients can compensate for sensory losses, and providing pureed foods that retain the cognitive integrity of a meal can benefit the patient who has chewing or swallowing problems

  14. A parallel machine extension to aversion dynamics scheduling

    Directory of Open Access Journals (Sweden)

    Gary W. Black

    2012-08-01

    Full Text Available The aversion dynamics research agenda has incorporated within dispatching heuristics a number of real-world observations involving risk mitigation practices used by real schedulers. One such observation is that schedulers occasionally offload risky jobs from a primary machine to otherwise less desirable machine (older, slower during periods of peak load to avoid the effects the risky job can have on subsequent jobs. This paper examines this situation within the proportional parallel machine environment. Safety time is used to adjust dispatching priorities of risky jobs to reflect the aversion. The effect of various safety time values on performance is studied. Robust safety time values and/or intervals are identified across a variety of experimental factors related to risk level, percent risky jobs in the job stream, and due date distribution.

  15. Eliciting and Measuring Betrayal Aversion using the BDM Mechanism*

    Science.gov (United States)

    Quercia, Simone

    2016-01-01

    Betrayal aversion has been operationalized as the evidence that subjects demand a higher risk premium to take social risks compared to natural risks. This evidence has been first shown by Bohnet and Zeckhauser (2004) using an adaptation of the Becker – DeGroot – Marschak mechanism (BDM, Becker et al. (1964)). We compare their implementation of the BDM mechanism with a new version designed to facilitate subjects’ comprehension. We find that, although the two versions produce different distributions of values, the size of betrayal aversion, measured as an average treatment difference between social and natural risk settings, is not different across the two versions. We further show that our implementation is preferable to use in practice as it reduces substantially subjects’ mistakes and the likelihood of noisy valuations. PMID:27366658

  16. Modeling Inequity Aversion in a Dictator Game with Production

    Directory of Open Access Journals (Sweden)

    Ismael Rodriguez-Lara

    2012-10-01

    Full Text Available We expand upon the previous models of inequity aversion of Fehr and Schmidt [1], and Frohlich et al. [2], which assume that dictators get disutility if the final allocation of surplus deviates from the equal split (egalitarian principle or from the subjects' production (libertarian principle. In our model, dictators may also account for the way in which the surplus was generated. More precisely, our model incorporates the idea of liberal egalitarian ethics into the analysis, making it possible for dictators to divide the surplus according to the accountability principle, which states that subjects should only be rewarded for factors under their control. This fairness ideal does not hold subjects responsible for factors beyond their control in the production of the surplus, an idea that is absent in the models of inequity aversion cited above (JEL Codes: D3, D6, D63.

  17. Lateral Habenula determines long-term storage of aversive memories.

    Directory of Open Access Journals (Sweden)

    Micol eTomaiuolo

    2014-05-01

    Full Text Available The Lateral Habenula (LHb is a small brain structure that codifies negative motivational value and has been related to major depression. It has been shown recently that LHb activation is sufficient to induce aversive associative learning; however the key question about whether LHb activation is required for an aversive memory to be formed has not been addressed. In this article we studied the function of the LHb in memory formation using the Inhibitory Avoidance task (IA. We found that LHb inactivation during IA training does not disrupt memory when assessed 24 hours after, but abolishes it 7 days later, indicating that LHb activity during memory acquisition is not necessary for memory formation, but regulates its temporal stability. These effects suggest that LHb inactivation modifies subjective perception of the training experience.

  18. Biophysics of risk aversion based on neurotransmitter receptor theory

    OpenAIRE

    Takahashi, Taiki

    2011-01-01

    Decision under risk and uncertainty has been attracting attention in neuroeconomics and neuroendocrinology of decision-making. This paper demonstrated that the neurotransmitter receptor theory-based value (utility) function can account for human and animal risk-taking behavior. The theory predicts that (i) when dopaminergic neuronal response is efficiently coupled to the formation of ligand-receptor complex, subjects are risk-aversive (irrespective of their satisfaction level) and (ii) when t...

  19. Parallel reinforcement pathways for conditioned food aversions in the honeybee

    OpenAIRE

    Wright, Geraldine A.; Mustard, Julie A; Simcock, Nicola K.; Ross-Taylor, Alexandra A.R.; McNicholas, Lewis D.; Popescu, Alexandra; Marion-Poll, Frederic

    2010-01-01

    Summary Avoiding toxins in food is as important as obtaining nutrition. Conditioned food aversions have been studied in animals as diverse as nematodes and humans [1, 2], but the neural signaling mechanisms underlying this form of learning have been difficult to pinpoint. Honeybees quickly learn to associate floral cues with food [3], a trait that makes them an excellent model organism for studying the neural mechanisms of learning and memory. Here we show that honeybees not only detect toxin...

  20. Pharmacological modulation of aversive responsiveness in honey bees

    OpenAIRE

    Tedjakumala, Stevanus R.; Aimable, Margaux; Giurfa, Martin

    2014-01-01

    Within a honey bee colony, individuals performing different tasks exhibit different sensitivities to noxious stimuli. Noxious-stimulus sensitivity can be quantified in harnessed bees by measuring the sting extension response (SER) to a series of increasing voltages. Biogenic amines play a crucial role in the control of insect responsiveness. Whether or not these neurotransmitters affect the central control of aversive responsiveness, and more specifically of electric-shock responsiveness, rem...

  1. Incomplete Procurement Contracting with a Risk-Averse Agent

    OpenAIRE

    Takeshi Nishimura

    2011-01-01

    In a two-stage procurement model, we compare two types of fixed-price contracting schemes, bundling and unbundling. The buyer's choice of scheme involves an intertemporal tradeoff: providing incentives for cost-reducing investment and sharing production-cost risk between the risk-neutral buyer and the risk-averse supplier. The main result shows that unbundling outperforms bundling when both the supplier and the entrant in ex post competitive bidding confront an aggregate risk, and the externa...

  2. Risk aversion and determinants of stock market behavior

    OpenAIRE

    Robert S. Pindyck

    1986-01-01

    A simple model of equity pricing is developed to address two related questions. First, to what extent can unanticipated changes in such"fundamental" variables as profitability, real interest rates, inflation, and the variance of returns account for the observed behavior of the stockmarket? Second, how risk averse are investors in the aggregate?We find that the pretax profit rate and the variance of returns are both significant explanators of the market, and interest rates somewhat less so. Es...

  3. Lack of insula reactivity to aversive stimuli in schizophrenia

    OpenAIRE

    Linnman, Clas; Coombs, Garth; Goff, Donald C.; Daphne J. Holt

    2012-01-01

    Patients with schizophrenia may have altered pain perception, as suggested by clinical reports of pain insensitivity, and recent neuroimaging findings. Here, we examined neural responses to an aversive electrical stimulus and the immediate anticipation of such a stimulus using fMRI and a classical conditioning paradigm, which involved pairing an electrical shock with a neutral photograph. Fifteen men with schizophrenia and 13 healthy men, matched for demographic characteristics, electrical st...

  4. Justice among strangers. On altruism, inequality aversion and fairness

    OpenAIRE

    Luciano Andreozzi; Matteo Ploner; Ivan Soraperra

    2013-01-01

    We present an axiomatic model of choice involving two agents, motivated by the experimental evidence on non-selfish preferences. We distinguish two classes of social preferences, depending on whether they are or not separable. Altruism and spite (Andreoni & Miller, 2002; Cox et al., 2007) are separable, while the various forms of inequality aversion are not (Fehr & Schmidt, 1999; Bolton & Ockenfels, 2000; Charness & Rabin, 2002). Separable and non-separable preferences give very close predict...

  5. Inequality Aversion, Efficiency, and Maximin Preferences in Simple Distribution Experiments

    OpenAIRE

    Dirk Engelmann; Martin Strobel

    2004-01-01

    We present simple one-shot distribution experiments comparing the relative importance of efficiency concerns, maximin preferences, and inequality aversion, as well as the relative performance of the fairness theories by Gary E Bolton and Axel Ockenfels and by Ernst Fehr and Klaus M. Schmidt. While the Fehr-Schmidt theory performs better in a direct comparison, this appears to be due to being in line with maximin preferences. More importantly, we find that a combination of efficiency concerns,...

  6. Conditioned food aversion to control Palicourea aeneofusca poisoning

    Directory of Open Access Journals (Sweden)

    Murilo Duarte Oliveira

    2014-07-01

    Full Text Available Palicourea aeneofusca contains sodium monofluoroacetate, which causes sudden death in ruminants when administered at doses of approximately 0.6g kg-1 of body weight (g kg-1. In this experiment two groups of 6 goats were used to determine the possibility to induce conditioned food aversion to P. aeneofusca. In group 1, 0.35g kg-1 of green leaves of the plant were given to six goats on days 1, 5, 10, 20, 30, 60, and 90 of the experiment. On the first day, all of the goats ingested the full amount of the plant and were treated immediately with 175mg kg-1 of lithium chloride (LiCl through a ruminal tube. On day 5, only two goats ingested the plant, and they were treated with the same dose of LiCl. On days 10, 20, 30, 60, and 90, none of the goats ingested the plant. For another group of 6 goats, the leaves were given on days 1, 10, 20, 30, 60, and 90. All of the goats ingested the leaves on day 1 and received 1mL kg-1 body weight of water through a ruminal tube. All of these goats ingested the plant on days 10, 20, 30, 60, and 90. These results demonstrate that it is possible to induce conditioned food aversion to P. aeneofusca that persists for at least 90 days. Further experiments should be performed to determine the duration of the aversion and to induce aversion to other Palicourea species, particularly P. marcgravii, which is the most important toxic plant in Brazil.

  7. On Monopoly Insurance Pricing when Agents Differ in Risk Aversion

    OpenAIRE

    Annette Hofmann; Martin Nell; Philipp Pohl

    2009-01-01

    The paper analyzes a monopolistic insurer’s pricing strategies when potential customers differ in risk aversion and their type cannot be observed by the insurer. Our model builds on Schlesinger (1983), who derived optimal nonlinear pricing strategies for competitive and monopolistic insurance markets. While Schlesinger assumed existence, we are concerned with conditions under which optimal strategies may exist. We introduce a general model framework for continuous but not necessarily differen...

  8. Interactions of temperature and taste in conditioned aversions

    OpenAIRE

    Smith, Patrick L.; Smith, James C.; Houpt, Thomas A.

    2009-01-01

    The the influence of temperature on taste cues and the ability to discriminate and learn about different temperatures of foods are important factors regulating ingestion. The goal of this research was to demonstrate that thermal orosensory input can serve as a salient stimulus to guide ingestive behavior in the rat, and also that it interacts with gustatory input during choice and conditioned aversion experiments. A novel apparatus with Peltier refrigerators was used to control the temperatur...

  9. Inequality aversion and separability in social risk evaluation

    OpenAIRE

    Fleurbaey, Marc; Zuber, Stéphane

    2011-01-01

    This paper examines how to satisfy a separability condition related to “independence of the utilities of the dead” (Blackorby et al., 1995; Bommier and Zuber, 2008) in the class of “expected equally distributed equivalent” social orderings (Fleurbaey, 2010). It also inquires into the possibility to keep some aversion to inequality in this context. It is shown that the social welfare function must either be utilitarian or take a special multiplicative form. The multiplicative form is compatibl...

  10. Regret Aversion and False Reference Points in Residential Real Estate

    OpenAIRE

    Michael J. Seiler; Vicky L. Seiler; Stefan Traub; David M. Harrison

    2008-01-01

    This study empirically exams the combination of regret aversion and false reference points in a residential real estate context. Survey respondents were put in a hypothetical situation, where they had purchased an investment property several years ago. Hindsight knowledge about a foregone all time high was introduced. As hypothesized, respondents on average expressed higher regret if they had actively failed to sell at the all time high (commission scenario) than if they had simply been unawa...

  11. Market Informational Inefficiency, Risk Aversion and Quantity Grid

    OpenAIRE

    Décamps, Jean-Paul; Lovo, Stefano

    2003-01-01

    In this paper we show that long run market informational inefficiency is perfectly compatible with standard rational sequential trade models. Our inefficiency result is obtained taking into account two features of actual financial markets: tradable quantities belong to a quantity grid and traders and market makers do not have the same degree of risk aversion. The implementation of our model for reasonable values of the parameters suggests that the long term deviations between asset prices and...

  12. Impaired Conditioned Taste Aversion Learning in Spinophilin Knockout Mice

    OpenAIRE

    Stafstrom-Davis, Carrie A.; Ouimet, Charles C.; Feng, Jian; Allen, Patrick B; Greengard, Paul; Houpt, Thomas A.

    2001-01-01

    Plasticity in dendritic spines may underlie learning and memory. Spinophilin, a protein enriched in dendritic spines, has the properties of a scaffolding protein and is believed to regulate actin cytoskeletal dynamics affecting dendritic spine morphology. It also binds protein phosphatase-1 (PP-1), an enzyme that regulates dendritic spine physiology. In this study, we tested the role of spinophilin in conditioned taste aversion learning (CTA) using transgenic spinophilin knockout mice. CTA is...

  13. Risk Aversion and Dynamic Games Between Hydroelectric Operators under Uncertainty

    OpenAIRE

    Abdessalem Abbassi; Ahlem Dakhlaoui; Tamini, Lota D.

    2014-01-01

    This article analyses management of hydropower dams within monopolistic and oligopolistic competition and when hydroelectricity producers are risk averse and face demand uncertainty. In each type of market structure we analytically determine the water release path in closed-loop equilibrium. We show how a monopoly can manage its hydropower dams by additional pumping or storage depending on the relative abundance of water between different regions to smooth the effect of uncertainty on electri...

  14. Loss Aversion, Adaptive Beliefs, and Asset Pricing Dynamics

    Directory of Open Access Journals (Sweden)

    Kamal Samy Selim

    2015-01-01

    Full Text Available We study asset pricing dynamics in artificial financial markets model. The financial market is populated with agents following two heterogeneous trading beliefs, the technical and the fundamental prediction rules. Agents switch between trading rules with respect to their past performance. The agents are loss averse over asset price fluctuations. Loss aversion behaviour depends on the past performance of the trading strategies in terms of an evolutionary fitness measure. We propose a novel application of the prospect theory to agent-based modelling, and by simulation, the effect of evolutionary fitness measure on adaptive belief system is investigated. For comparison, we study pricing dynamics of a financial market populated with chartists perceive losses and gains symmetrically. One of our contributions is validating the agent-based models using real financial data of the Egyptian Stock Exchange. We find that our framework can explain important stylized facts in financial time series, such as random walk price behaviour, bubbles and crashes, fat-tailed return distributions, power-law tails in the distribution of returns, excess volatility, volatility clustering, the absence of autocorrelation in raw returns, and the power-law autocorrelations in absolute returns. In addition to this, we find that loss aversion improves market quality and market stability.

  15. AN INVESTIGATION OF THE RELATIONSHIP BETWEEN CONSTRAINT OMISSION AND RISK AVERSION IN FIRM RISK PROGRAMMNG MODELS

    OpenAIRE

    Musser, Wesley N.; McCarl, Bruce A.; Smith, G. Scott

    1986-01-01

    A model with omitted resource constraints is suggested as an alternative to a risk aversion model for explaining economic behavior. This paper uses two standard mathematical programming models to further explore this issue. One model is a standard profit maximization linear programming model and the other is a risk averse quadratic programming model with part of the constraints deleted. Theoretical investigation of these models demonstrates that risk aversion can substitute for omitted resour...

  16. Risk Aversion is Associated with Decision Making among Community-Based Older Persons

    OpenAIRE

    Boyle, Patricia A; Yu, Lei; Buchman, Aron S.; Bennett, David A.

    2012-01-01

    Background: Risk aversion is associated with many important decisions among younger and middle aged persons, but the association of risk aversion with decision making has not been well studied among older persons who face some of the most significant decisions of their lives. Method: Using data from 606 community-dwelling older persons without dementia from the Rush Memory and Aging Project, an ongoing longitudinal epidemiologic study of aging, we examined the association of risk aversion wit...

  17. Risk Aversion is Associated with Decision Making among Community-Based Older Persons

    OpenAIRE

    Patricia eBoyle; Lei eYu; Aron eBuchman; David eBennett

    2012-01-01

    Background: Risk aversion is associated with many important decisions among younger and middle aged persons, but the association of risk aversion and decision making has not been well studied among older persons who face some of the most significant decisions of their lives. Method: Using data from 606 community-dwelling older persons without dementia from the Rush Memory and Aging Project, an ongoing longitudinal epidemiologic study of aging, we examined the association of risk aversion w...

  18. Conditioned Food Aversions: Principles and Practices, with Special Reference to Social Facilitation

    OpenAIRE

    Ralphs, Michael H.; Provenza, Frederick D

    1999-01-01

    Conditioned food aversion is a powerful experimental tool to modify animal diets. We have also investigated it as a potential management tool to prevent livestock from grazing poisonous plants such as tall larkspur (Delphinium barbeyi), white locoweed (Oxytropis sericea) and ponderosa pine (Pinus ponderosa) on western US rangelands. The following principles pertain to increasing the strength and longevity of aversions: mature animals retain aversions better than young animals; novelty of the ...

  19. Coordination of a Random Yield Supply Chain with a Loss-Averse Supplier

    OpenAIRE

    Jiarong Luo; Xu Chen

    2015-01-01

    This paper investigates the coordination of a supply chain consisting of a loss-averse supplier and a risk-neutral buyer who orders products from the supplier who suffers from random yield to meet a deterministic demand. We derive the risk-neutral buyer’s optimal order policy and the loss-averse supplier’s optimal production policy under shortage-penalty-surplus-subsidy (SPSS) contracts. We also analyze the impacts of loss aversion on the loss-averse supplier’s production decision making and ...

  20. Simulating the market coefficient of relative risk aversion

    Directory of Open Access Journals (Sweden)

    Samih Antoine Azar

    2014-12-01

    Full Text Available In this paper, expected utility, defined by a Taylor series expansion around expected wealth, is maximized. The coefficient of relative risk aversion (CRRA that is commensurate with a 100% investment in the risky asset is simulated. The following parameters are varied: the riskless return, the market standard deviation, the market stock premium, and the skewness and the kurtosis of the risky return. Both the high extremes and the low extremes are considered. With these figures, the upper bound of the market CRRA is 3.021 and the lower bound is 0.466. Log utility, which corresponds to a CRRA of 1, is not excluded.

  1. METABOTROPIC GLUTAMATE RECEPTOR 5 IN CONDITIONED TASTE AVERSION LEARNING

    OpenAIRE

    Simonyi, A.; Serfozo, P.; Parker, K.E.; Ramsey, A.K.; Schachtman, T.R.

    2009-01-01

    In conditioned taste aversion (CTA), animals learn to avoid a flavored solution (conditioned stimulus, CS) previously paired with internal malaise (unconditioned stimulus, US). Metabotropic glutamate receptor 5 (mGlu5) has been implicated in learning and memory processes and is necessary for CTA. In the present study, local microinjections of a mGlu5-selective antagonist, 3-[2-methyl-1,3-thiazol-4yl)ethynyl]pyridine (MTEP, 0, 1 or 5 μg) into the insular cortex and basolateral amygdala were us...

  2. Dismissing Attachment Characteristics Dynamically Modulate Brain Networks Subserving Social Aversion

    Science.gov (United States)

    Krause, Anna Linda; Borchardt, Viola; Li, Meng; van Tol, Marie-José; Demenescu, Liliana Ramona; Strauss, Bernhard; Kirchmann, Helmut; Buchheim, Anna; Metzger, Coraline D.; Nolte, Tobias; Walter, Martin

    2016-01-01

    Attachment patterns influence actions, thoughts and feeling through a person’s “inner working model”. Speech charged with attachment-dependent content was proposed to modulate the activation of cognitive-emotional schemata in listeners. We performed a 7 Tesla rest-task-rest functional magnetic resonance imaging (fMRI)-experiment, presenting auditory narratives prototypical of dismissing attachment representations to investigate their effect on 23 healthy males. We then examined effects of participants’ attachment style and childhood trauma on brain state changes using seed-based functional connectivity (FC) analyses, and finally tested whether subjective differences in responsivity to narratives could be predicted by baseline network states. In comparison to a baseline state, we observed increased FC in a previously described “social aversion network” including dorsal anterior cingulated cortex (dACC) and left anterior middle temporal gyrus (aMTG) specifically after exposure to insecure-dismissing attachment narratives. Increased dACC-seeded FC within the social aversion network was positively related to the participants’ avoidant attachment style and presence of a history of childhood trauma. Anxious attachment style on the other hand was positively correlated with FC between the dACC and a region outside of the “social aversion network”, namely the dorsolateral prefrontal cortex, which suggests decreased network segregation as a function of anxious attachment. Finally, the extent of subjective experience of friendliness towards the dismissing narrative was predicted by low baseline FC-values between hippocampus and inferior parietal lobule (IPL). Taken together, our study demonstrates an activation of networks related to social aversion in terms of increased connectivity after listening to insecure-dismissing attachment narratives. A causal interrelation of brain state changes and subsequent changes in social reactivity was further supported by

  3. Dismissing attachment characteristics dynamically modulate brain networks subserving social aversion.

    Directory of Open Access Journals (Sweden)

    Anna Linda eKrause

    2016-03-01

    Full Text Available Attachment patterns influence actions, thoughts and feeling through a person’s ‘Inner Working Model’. Speech charged with attachment-dependent content was proposed to modulate the activation of cognitive-emotional schemata in listeners. We performed a 7 Tesla rest-task-rest fMRI-experiment, presenting auditory narratives prototypical of dismissing attachment representations to investigate their effect on 23 healthy males. We then examined effects of participants’ attachment style and childhood trauma on brain state changes using seed-based functional connectivity (FC analyses, and finally tested whether subjective differences in responsivity to narratives could be predicted by baseline network states. In comparison to a baseline state, we observed increased FC in a previously described ‘social aversion network’ including dorsal anterior cingulated cortex (dACC and left anterior middle temporal gyrus (aMTG specifically after exposure to insecure-dismissing attachment narratives. Increased dACC-seeded FC within the social aversion network was positively related to the participants’ avoidant attachment style and presence of a history of childhood trauma. Anxious attachment style on the other hand was positively correlated with FC between the dACC and a region outside of the ‘social aversion network’, namely the dorsolateral prefrontal cortex, which suggests decreased network segregation as a function of anxious attachment. Finally, the extent of subjective experience of friendliness towards the dismissing narrative was predicted by low baseline FC-values between hippocampus and inferior parietal lobule. Taken together, our study demonstrates an activation of networks related to social aversion in terms of increased connectivity after listening to insecure-dismissing attachment narratives. A causal interrelation of brain state changes and subsequent changes in social reactivity was further supported by our observation of direct

  4. FLAVOR AVERSIONS INDUCED BY THALLIUM SULFATE: IMPORTANCE OF ROUTE OF ADMINISTRATION

    Science.gov (United States)

    Flavor aversions induced by thallium sulfate: Importance of route of administration. Neurobehavioral Toxicology and Teratology, 00: 00-00, 1985. Flavor aversions induced by intraperitoneal (i.p.) and oral (p.o.) administration of thallium sulfate were compared in a repeated trial...

  5. Coordination of a Random Yield Supply Chain with a Loss-Averse Supplier

    Directory of Open Access Journals (Sweden)

    Jiarong Luo

    2015-01-01

    Full Text Available This paper investigates the coordination of a supply chain consisting of a loss-averse supplier and a risk-neutral buyer who orders products from the supplier who suffers from random yield to meet a deterministic demand. We derive the risk-neutral buyer’s optimal order policy and the loss-averse supplier’s optimal production policy under shortage-penalty-surplus-subsidy (SPSS contracts. We also analyze the impacts of loss aversion on the loss-averse supplier’s production decision making and find that the loss-averse supplier may produce less than, equal to, or more than the risk-neutral supplier. Then, we provide explicit conditions on which the random yield supply chain with a loss-averse supplier can be coordinated under SPSS contracts. Finally, adopting numerical examples, we find that when the shortage penalty is low, the buyer’s optimal order quantity will increase, while the supplier’s optimal production quantity will first decrease and then increase as the loss aversion level increases. When the shortage penalty is high, the buyer’s optimal order quantity will decrease but the supplier’s optimal production quantity will always increase as the loss aversion level increases. Furthermore, the numerical examples provide strong evidence for the view that SPSS contracts can effectively improve the performance of the whole supply chain.

  6. Preexposure to Salty and Sour Taste Enhances Conditioned Taste Aversion to Novel Sucrose

    Science.gov (United States)

    Flores, Veronica L.; Moran, Anan; Bernstein, Max; Katz, Donald B.

    2016-01-01

    Conditioned taste aversion (CTA) is an intensively studied single-trial learning paradigm whereby animals are trained to avoid a taste that has been paired with malaise. Many factors influence the strength of aversion learning; prominently studied among these is taste novelty--the fact that preexposure to the taste conditioned stimulus (CS)…

  7. Appetitive but Not Aversive Olfactory Conditioning Modifies Antennal Movements in Honeybees

    Science.gov (United States)

    Cholé, Hanna; Junca, Pierre; Sandoz, Jean-Christophe

    2015-01-01

    In honeybees, two olfactory conditioning protocols allow the study of appetitive and aversive Pavlovian associations. Appetitive conditioning of the proboscis extension response (PER) involves associating an odor, the conditioned stimulus (CS) with a sucrose solution, the unconditioned stimulus (US). Conversely, aversive conditioning of the sting…

  8. The Effect of Ambiguity Aversion on Insurance and Self-protection

    OpenAIRE

    Alary, David; GOLLIER Christian; Treich, Nicolas

    2013-01-01

    In this paper, we derive a set of simple conditions such that ambiguity aversion always raises the demand for self-insurance and the insurance coverage, but decreases the demand for self-protection. We also characterize the optimal insurance design under ambiguity aversion, and exhibit a case in which the straight deductible contract is optimal as in the expected utility model.

  9. Small- and large-stakes risk aversion: implications of concavity calabration for decision theory

    NARCIS (Netherlands)

    J.C. Cox; V. Sadiraj

    2006-01-01

    A growing literature reports the conclusions that: (a) expected utility theory does not provide a plausible theory of risk aversion for both small-stakes and large-stakes gambles; and (b) this decision theory should be replaced with an alternative theory characterized by loss aversion. This paper ex

  10. Optimal Consumption and Investment under Time-Varying Relative Risk Aversion

    DEFF Research Database (Denmark)

    Steffensen, Mogens

    2011-01-01

    We consider the continuous time consumption-investment problem originally formalized and solved by Merton in case of constant relative risk aversion. We present a complete solution for the case where relative risk aversion with respect to consumption varies with time, having in mind an investor...

  11. Conditioned food aversion for control of poisoning by Ipomoea carnea subsp. fistulosa

    Science.gov (United States)

    Conditioned food aversion is a technique that can be used to train livestock to avoid ingestion of poisonous plants. This study tested the efficacy and durability of conditioned food aversion to eliminate goat’s consumption of Ipomoea carnea subsp. fistulosa. We used 14 young Moxotó goats, which wer...

  12. RSK2 Signaling in Brain Habenula Contributes to Place Aversion Learning

    Science.gov (United States)

    Darcq, Emmanuel; Koebel, Pascale; Del Boca, Carolina; Pannetier, Solange; Kirstetter, Anne-Sophie; Garnier, Jean-Marie; Hanauer, Andre; Befort, Katia; Kieffer, Brigitte L.

    2011-01-01

    RSK2 is a Ser/Thr kinase acting in the Ras/MAPK pathway. "Rsk2" gene deficiency leads to the Coffin-Lowry Syndrome, notably characterized by cognitive deficits. We found that "mrsk2" knockout mice are unable to associate an aversive stimulus with context in a lithium-induced conditioned place aversion task requiring both high-order cognition and…

  13. The capsaicin receptor participates in artificial sweetener aversion.

    Science.gov (United States)

    Riera, Céline E; Vogel, Horst; Simon, Sidney A; Damak, Sami; le Coutre, Johannes

    2008-11-28

    Artificial sweeteners such as saccharin, aspartame, acesulfame-K, and cyclamate produce at high concentrations an unpleasant after-taste that is generally attributed to bitter and metallic taste sensations. To identify receptors involved with the complex perception of the above compounds, preference tests were performed in wild-type mice and mice lacking the TRPV1 channel or the T1R3 receptor, the latter being necessary for the perception of sweet taste. The sweeteners, including cyclamate, displayed a biphasic response profile, with the T1R3 mediated component implicated in preference. At high concentrations imparting off-taste, omission of TRPV1 reduced aversion. In a heterologous expression system the Y511A point mutation in the vanilloid pocket of TRPV1 did not affect saccharin and aspartame responses but abolished cyclamate and acesulfame-K activities. The results rationalize artificial sweetener tastes and off-tastes by showing that at low concentrations, these molecules stimulate the gustatory system through the hedonically positive T1R3 pathway, and at higher concentrations, their aversion is partly mediated by TRPV1. PMID:18804451

  14. The Commonality of Loss Aversion across Procedures and Stimuli

    Science.gov (United States)

    Kim, Byoung W.; Gilman, Jodi M.; Kuster, John K.; Blood, Anne J.; Kuhnen, Camelia M.

    2015-01-01

    Individuals tend to give losses approximately 2-fold the weight that they give gains. Such approximations of loss aversion (LA) are almost always measured in the stimulus domain of money, rather than objects or pictures. Recent work on preference-based decision-making with a schedule-less keypress task (relative preference theory, RPT) has provided a mathematical formulation for LA similar to that in prospect theory (PT), but makes no parametric assumptions in the computation of LA, uses a variable tied to communication theory (i.e., the Shannon entropy or information), and works readily with non-monetary stimuli. We evaluated if these distinct frameworks described similar LA in healthy subjects, and found that LA during the anticipation phase of the PT-based task correlated significantly with LA related to the RPT-based task. Given the ease with which non-monetary stimuli can be used on the Internet, or in animal studies, these findings open an extensive range of applications for the study of loss aversion. Furthermore, the emergence of methodology that can be used to measure preference for both social stimuli and money brings a common framework to the evaluation of preference in both social psychology and behavioral economics. PMID:26394306

  15. The Commonality of Loss Aversion across Procedures and Stimuli.

    Directory of Open Access Journals (Sweden)

    Sang Lee

    Full Text Available Individuals tend to give losses approximately 2-fold the weight that they give gains. Such approximations of loss aversion (LA are almost always measured in the stimulus domain of money, rather than objects or pictures. Recent work on preference-based decision-making with a schedule-less keypress task (relative preference theory, RPT has provided a mathematical formulation for LA similar to that in prospect theory (PT, but makes no parametric assumptions in the computation of LA, uses a variable tied to communication theory (i.e., the Shannon entropy or information, and works readily with non-monetary stimuli. We evaluated if these distinct frameworks described similar LA in healthy subjects, and found that LA during the anticipation phase of the PT-based task correlated significantly with LA related to the RPT-based task. Given the ease with which non-monetary stimuli can be used on the Internet, or in animal studies, these findings open an extensive range of applications for the study of loss aversion. Furthermore, the emergence of methodology that can be used to measure preference for both social stimuli and money brings a common framework to the evaluation of preference in both social psychology and behavioral economics.

  16. Prevention of radiation induced taste aversion in rats

    International Nuclear Information System (INIS)

    Diltiazem, a calcium channel blocker, and a cardiovascular therapeutic agent offers significant protection to mice against lethal dose of ionizing radiation. Considering the potential efficacy of diltiazem as a radioprotector for human use, it was deemed necessary to investigate its influence on radiation-induced behavioural changes like nausea, vomiting, learning, memory and performance. In the present studies, conditioned taste aversion (CTA) test based on consumption of saccharin solution, was used as a marker of behavioural changes. Significant CTA (97±2%) was observed in rats irradiated with 60Co gamma rays (absorbed dose 1 Gy). Administration of diltiazem at doses greater than 10 mg/kg, body wt, evoked CTA in a dose-dependent manner and that was found to be further aggravated on irradiation. At a lower dose of 5 mg/kg, body wt, diltiazem did not evoke CTA and protected against radiation induced aversion significantly (62±3%). The results suggest that diltiazem at concentrations lower than 10 mg/kg, body wt, in rats may be useful in preventing radiation induced behavioural changes. This observation could be of particular significance in clinical radiotherapy where radiation induced nausea and vomiting are of great concern. (author)

  17. The importance of risk-aversion as a measurable psychological parameter governing risk-taking behaviour

    International Nuclear Information System (INIS)

    A utility function with risk-aversion as its sole parameter is developed and used to examine the well-known psychological phenomenon, whereby risk averse people adopt behavioural strategies that are extreme and apparently highly risky. The pioneering work of the psychologist, John W. Atkinson, is revisited, and utility theory is used to extend his mathematical model. His explanation of the psychology involved is improved by regarding risk-aversion not as a discrete variable with three possible states: risk averse, risk neutral and risk confident, but as continuous and covering a large range. A probability distribution is derived, the motivational density, to describe the process of selecting tasks of different degrees of difficulty. An assessment is then made of practicable methods for measuring risk-aversion

  18. Taste aversion learning produced by combined treatment with subthreshold radiation and lithium chloride

    International Nuclear Information System (INIS)

    These experiments were designed to determine whether treatment with two subthreshold doses of radiation or lithium chloride, either alone or in combination, could lead to taste aversion learning. The first experiment determined the thresholds for a radiation-induced taste aversion at 15-20 rad and for lithium chloride at 0.30-0.45 mEq/kg. In the second experiment it was shown that exposing rats to two doses of 15 rad separated by up to 3 hr produced a taste aversion. Treatment with two injections of lithium chloride (0.30 mEq/kg) did not produce a significant reduction in preference. Combined treatment with radiation and lithium chloride did produce a taste aversion when the two treatments were administered within 1 hr of each other. The results are discussed in terms of the implications of these findings for understanding the nature of the unconditioned stimuli leading to the acquisition of a conditioned taste aversion

  19. The importance of risk-aversion as a measurable psychological parameter governing risk-taking behaviour

    Science.gov (United States)

    Thomas, P. J.

    2013-09-01

    A utility function with risk-aversion as its sole parameter is developed and used to examine the well-known psychological phenomenon, whereby risk averse people adopt behavioural strategies that are extreme and apparently highly risky. The pioneering work of the psychologist, John W. Atkinson, is revisited, and utility theory is used to extend his mathematical model. His explanation of the psychology involved is improved by regarding risk-aversion not as a discrete variable with three possible states: risk averse, risk neutral and risk confident, but as continuous and covering a large range. A probability distribution is derived, the "motivational density", to describe the process of selecting tasks of different degrees of difficulty. An assessment is then made of practicable methods for measuring risk-aversion.

  20. Biophysics of risk aversion based on neurotransmitter receptor theory

    CERN Document Server

    Takahashi, Taiki

    2011-01-01

    Decision under risk and uncertainty has been attracting attention in neuroeconomics and neuroendocrinology of decision-making. This paper demonstrated that the neurotransmitter receptor theory-based value (utility) function can account for human and animal risk-taking behavior. The theory predicts that (i) when dopaminergic neuronal response is efficiently coupled to the formation of ligand-receptor complex, subjects are risk-aversive (irrespective of their satisfaction level) and (ii) when the coupling is inefficient, subjects are risk-seeking at low satisfaction levels, consistent with risk-sensitive foraging theory in ecology. It is further suggested that some anomalies in decision under risk are due to inefficiency of the coupling between dopamine receptor activation and neuronal response. Future directions in the application of the model to studies in neuroeconomics of addiction and neuroendocrine modulation of risk-taking behavior are discussed.

  1. Risk aversion and agents' survivability in a financial market

    Institute of Scientific and Technical Information of China (English)

    Serge HAYWARD

    2009-01-01

    Considering the effect of economic agents' pref-erences on their actions, the relationships between conven-tional summary statistics and forecast profits are investi-gated. An analytical examination of loss function families demonstrates that investors' utility maximisation is deter-mined by their risk attitudes. In computational settings,stock traders' fitness is assessed in response to a slow step increase in the value of the risk aversion coefficient. The ex-periment rejects the claims that the accuracy of the forecast does not depend upon which error-criteria are used and that none of them is related to the profitability of the forecast.The profitability of networks trained with L6 loss function appeared to be statistically significant and stable, although links between the loss functions and the accuracy of fore-casts were less conclusive.

  2. Correlates of academic procrastination: discomfort, task aversiveness, and task capability.

    Science.gov (United States)

    Milgram, N; Marshevsky, S; Sadeh, C

    1995-03-01

    The relationships among five aspects of academic procrastination--behavioral delay, personal upset about the delay, task aversiveness, task capability, and the desire to reduce behavioral delay--were investigated in 10th-grade Israeli students (N = 195). Upset about delay was weakly related to delay itself, and--unlike delay--was strongly related to perceived capability to perform academic tasks and to the desire to change delaying behavior. Students delayed more on academic tasks labeled unpleasant than pleasant, were neutral in between, and were correspondingly more upset about the former than the latter. They more frequently acknowledged reasons for academic procrastination that were less threatening to their self-image (e.g., problems in time management) than reasons that were more threatening (e.g., lack of ability). Interest in reducing delay is related more to self-perceived ability to handle tasks than to time spent procrastinating or reasons given for procrastinating. PMID:7760291

  3. Supply Chain Coordination of Loss-Averse Newsvendor with Contract

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long; SONG Shiji; WU Cheng

    2005-01-01

    This paper studies a supply chain model in which a single supplier sells a single product to a single retailer who faces the newsvendor problem. The retailer is loss averse. The results show that the optimal production quantity with decentralized decision making with a wholesale price contract is less than that with centralized decision making. The supply chain can achieve channel coordination with buy back and target rebate contracts. With buy back contracts, the supply chain system profits can be allocated arbitrarily between the supplier and retailer. A new kind of contract, the incremental buy back contract, gives similar results as with the buy back contract. The advantages and drawbacks of these three types of contracts are analyzed with numerical examples.

  4. A Risk-Averse Inventory Model with Markovian Purchasing Costs

    Directory of Open Access Journals (Sweden)

    Sungyong Choi

    2015-01-01

    Full Text Available We study a few dynamic risk-averse inventory models using additive utility functions. We add Markovian behavior of purchasing costs in our models. Such Markovian purchasing costs can reflect a market situation in a global supply chain such as fluctuations at exchange rates or the existence of product spot markets. We provide our problem formulations with finite and infinite MDP (Markovian Decision Process problems. For finite time models, we first prove (joint concavity of the model for each state and obtain a (modified base-stock optimal policy. Then, we conduct comparative static analysis for model parameters and derive monotone properties to the optimal solutions. For infinite time models, we show the existence of stationary base-stock optimal policies and the inheritance of the monotone properties proven at our finite time models.

  5. Aversive conditioning in prenatally gamma-irradiated rats

    International Nuclear Information System (INIS)

    To examine how intrauterine exposure to gamma rays would exert on four kinds of aversive conditioning, rat fetuses were irradiated with 0.27, 0.48, or 1.46 Gy at Day 15 post conception. When ordinary avoidance conditioning was given to the groups with 0.27 and 0.48 Gy, there was no significant difference between the irradiated groups and the control group in the rate of positive avoidance response. Nor was this different in the irradiated groups and the control group, when the rate of baseline response was examined in avoidance conditioning. In positive avoidance conditioning to two kinds of anticipatory electric stimuli, the acquisition of avoidance was significantly inferior in all irradiated groups to that in the control group. When giving succesive discrimination learning, the group with 1.46 Gy tended to have higher rate of positive avoidance response and remarkably lower rate of passive avoidance response than the control group. (Namekawa, K.)

  6. [Misophonia or aversion to human sound: a clinical illustration].

    Science.gov (United States)

    Jacot, C-R; Eric, T; Sentissi, O

    2015-02-18

    Misophonia, meaning hatred of sound, is a cluster of symptoms which is not completely included in anxiety disorders category as obsessive compulsive or as an impulsivity disorder. It is described as a chronic condition characterized by reactions, aversion to specific sounds that result in subsequent emotional. Indeed, this condition is relatively unknown and few psychiatrists have already faced this disorder causing in some individuals severe impairment. The investigation of a patient suffering of misophonia with severe impairment that we took into care in an outpatient psychiatric clinic in Geneva contributes to a better understanding of this condition and indicates potential factors that may co-occur and influence the clinical presentation. The good response in psychotherapy, has led us to carry out a brief review of the literature in order to better define and identify this disorder. PMID:25915989

  7. Risk-Averse Agent Model for Human Bursty Dynamics

    CERN Document Server

    Jo, Hang-Hyun; Kaski, Kimmo

    2011-01-01

    Human dynamics is known to be inhomogeneous or bursty and is characterized by heavy tailed waiting time distributions. In order to describe the role of human factors in the bursty dynamics of individuals we devise and study a risk-averse agent model. In the model an agent in an uncertain or risky situation chooses an optimal waiting time when there exists a trade-off between information for reducing risk and cost of time spent for obtaining the information. By studying this model analytically we obtain a power-law distribution of waiting time and find that the effect of the efficiency for obtaining information is in all cases relevant for the scaling behavior of the waiting time distribution, while the cost of time turns out to be irrelevant in some cases.

  8. Pharmacological modulation of aversive responsiveness in honey bees

    Directory of Open Access Journals (Sweden)

    Martin Giurfa

    2014-01-01

    Full Text Available Within a honey bee colony, individuals performing different tasks exhibit different sensitivities to noxious stimuli. Noxious-stimulus sensitivity can be quantified in harnessed bees by measuring the sting extension response (SER to a series of increasing voltages. Biogenic amines play a crucial role in the control of insect responsiveness. Whether or not these neurotransmitters affect the central control of aversive responsiveness, and more specifically of electric-shock responsiveness, remains unknown. Here we studied the involvement of the biogenic amines octopamine, dopamine and serotonin, and of the ecdysteroid 20-hydroxyecdisone in the central control of sting responsiveness to electric shocks. We injected pharmacological antagonists of these signaling pathways into the brain of harnessed bees and determined the effect of blocking these different forms of neurotransmission on shock responsiveness. We found that both octopamine and 20-hydroxyecdisone are dispensable for shock responsiveness while dopamine and serotonin act as down-regulators of sting responsiveness. As a consequence, antagonists of these two biogenic amines induce an increase in shock responsiveness to shocks of intermediate voltage; serotonin, can also increase non-specific responsiveness. We suggest that different classes of dopaminergic neurons exist in the bee brain and we define at least two categories: an instructive class mediating aversive labeling of conditioned stimuli in associative learning, and a global gain-control class which down-regulates responsiveness upon perception of noxious stimuli. Serotonergic signaling together with down-regulating dopaminergic signaling may play an essential role in attentional processes by suppressing responses to irrelevant, non-predictive stimuli, thereby allowing efficient behavioral performances.

  9. Predator-Resembling Aversive Conditioning for Managing Habituated Wildlife

    Directory of Open Access Journals (Sweden)

    Colleen Cassady St. Clair

    2005-06-01

    Full Text Available Wildlife habituation near urban centers can disrupt natural ecological processes, destroy habitat, and threaten public safety. Consequently, management of habituated animals is typically invasive and often includes translocation of these animals to remote areas and sometimes even their destruction. Techniques to prevent or reverse habituation and other forms of in situ management are necessary to balance ecological and social requirements, but they have received very little experimental attention to date. This study compared the efficacy of two aversive conditioning treatments that used either humans or dogs to create sequences resembling chases by predators, which, along with a control category, were repeatedly and individually applied to 24 moderately habituated, radio-collared elk in Banff National Park during the winter of 2001–2002. Three response variables were measured before and after treatment. Relative to untreated animals, the distance at which elk fled from approaching humans, i.e., the flight response distance, increased following both human and dog treatments, but there was no difference between the two treatments. The proportion of time spent in vigilance postures decreased for all treatment groups, without differences among groups, suggesting that this behavior responded mainly to seasonal effects. The average distance between elk locations and the town boundary, measured once daily by telemetry, significantly increased for human-conditioned elk. One of the co-variates we measured, wolf activity, exerted counteracting effects on conditioning effects; flight response distances and proximity to the town site were both lower when wolf activity was high. This research demonstrates that it is possible to temporarily modify aspects of the behavior of moderately habituated elk using aversive conditioning, suggests a method for reducing habituation in the first place, and provides a solution for Banff and other jurisdictions to manage

  10. Medial frontal negativity reflects advantageous inequality aversion of proposers in the ultimatum game: An ERP study.

    Science.gov (United States)

    Wang, Guangrong; Li, Jianbiao; Li, Zheng; Wei, Mengxing; Li, Shaodong

    2016-05-15

    Inequality aversion is a typical form of fairness preferences, which can explain the behaviors in many social exchange situations such as the ultimatum game (UG). There are two kinds of inequality aversion-disadvantageous inequality aversion of responders and advantageous inequality aversion of proposers in the ultimatum game. Although neuroscience research has reported neural correlates of disadvantageous inequality aversion, there are still debates about advantageous inequality aversion of proposers. In this paper, we developed a variant of ultimatum game in which participants played the UG as proposers. On each trial, first, the offer was randomly presented, then, participants as proposers decided whether to choose this offer; next, responders decided whether to accept or not. Offers that responders got 1-20% of the pie are defined as advantageous unfair offers of proposers, whereas offers that responders got 31-50% are defined as fair offers. Event-related brain potentials recorded from the participants showed that more negative-going medial frontal negativity (MFN) was elicited by advantageous unfair offers compared to fair offers in the early time window (250-350ms), which suggested that proposers were averse to advantageous inequality. PMID:26930614

  11. Contrasting role of octopamine in appetitive and aversive learning in the crab Chasmagnathus.

    Directory of Open Access Journals (Sweden)

    Laura Kaczer

    Full Text Available BACKGROUND: Biogenic amines are implicated in reinforcing associative learning. Octopamine (OA is considered the invertebrate counterpart of noradrenaline and several studies in insects converge on the idea that OA mediates the reward in appetitive conditioning. However, it is possible to assume that OA could have a different role in an aversive conditioning. METHODOLOGY/PRINCIPAL FINDINGS: Here we pharmacologically studied the participation of OA in two learning processes in the crab Chasmagnathus granulatus, one appetitive and one aversive. It is shown that the aversive memory is impaired by an OA injection applied immediately or 30 minutes after the last training trial. By contrast, the appetitive memory is blocked by OA antagonists epinastine and mianserine, but enhanced by OA when injected together with the supply of a minimum amount of reinforcement. Finally, double-learning experiments in which crabs are given the aversive and the appetitive learning either successively or simultaneously allow us to study the interaction between both types of learning and analyze the presumed action of OA. We found that the appetitive training offered immediately, but not one hour, after an aversive training has an amnesic effect on the aversive memory, mimicking the effect and the kinetic of an OA injection. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that the role of OA is divergent in two memory processes of opposite signs: on the one hand it would mediate the reinforcement in appetitive learning, and on the other hand it has a deleterious effect over aversive memory consolidation.

  12. A comparison of dependent measures used to quantify radiation-induced taste aversion

    International Nuclear Information System (INIS)

    Several commonly used measures of conditioned taste aversion were compared under a variety of experimental conditions. In the first experiment an aversion to a saccharin solution (0.1%) was conditioned by pairing this taste substance with a single 100 R exposure to Cobalt-60. Comparisons were performed between the following measures: a short-term single-bottle test, a 22-hour two-bottle preference test, a measure quantifying recovery from the aversion along with other measures derived from these tests. Appropriate control groups received saccharin and sham exposure, water and sham exposure, and water and radiation exposure in order to measure both neophobia and enhanced neophobia. In Experiment 2 the total whole body radiation exposure used to condition the taste aversion was varied in different groups from 50 to 300 R exposures and the effect on conditioning was measured using the dependent variables described in Experiment 1. In Experiment 3 radiation-induced taste aversion was studied in rats which had prior exposures to the saccharin solution. In all three studies it was shown that different interpretations result from measuring the conditioned aversion with the different dependent variables commonly used, and several measures are needed to give a fair and accurate description of learned taste aversion. (author)

  13. Self-insurance, self-protection, and increased risk aversion: An intertemporal reinvestigation

    OpenAIRE

    Hofmann, Annette; Peter, Richard

    2012-01-01

    This paper studies the effect of increased risk aversion on self-insurance and self-protection in a two-period framework. Here risk management incentives and consumption smoothing incentives are traded off, and the monotonic relationship between self-insurance and risk aversion may no longer hold as more risk-averse agents cannot always afford spending more on self-insurance. A very similar relationship holds for self-protection making self-insurance and self-protection much more alike in a t...

  14. Random risk aversion and the cost of eliminating the foreign exchange risk of the Euro

    OpenAIRE

    Samih A Azar

    2010-01-01

    This paper answers the following questions. If the Euro foreign exchange risk is given, what is the cost of eliminating such a risk? How does risk aversion affect this cost? What is the relation between the insurance premium on the Euro and this cost? Is it possible to find out the level of risk aversion by looking upon actual risk-free yields? If risk aversion is random, how do risk-free yields move with the return on the Euro currency? Economists usually take for granted that preferences ar...

  15. A Preliminary Analysis of Self-Control with Aversive Events: The Effects of Task Magnitude and Delay on the Choices of Children with Autism

    Science.gov (United States)

    Lerman, Dorothea C.; Addison, Laura R.; Kodak, Tiffany

    2006-01-01

    When faced with a choice between two aversive events, a person exhibits self-control by choosing a smaller, more immediate aversive event over a larger, delayed aversive event. Task demands are often aversive to children with autism and other developmental disabilities. The purpose of this study was to evaluate behavioral sensitivity to…

  16. Medial prefrontal cortex dopamine controls the persistent storage of aversive memories

    Science.gov (United States)

    Gonzalez, María C.; Kramar, Cecilia P.; Tomaiuolo, Micol; Katche, Cynthia; Weisstaub, Noelia; Cammarota, Martín; Medina, Jorge H.

    2014-01-01

    Medial prefrontal cortex (mPFC) is essential for initial memory processing and expression but its involvement in persistent memory storage has seldom been studied. Using the hippocampus dependent inhibitory avoidance learning task and the hippocampus-independent conditioned taste aversion paradigm together with specific dopamine receptor agonists and antagonists we found that persistence but not formation of long-term aversive memories requires dopamine D1/D5 receptors activation in mPFC immediately after training and, depending on the task, between 6 and 12 h later. Our results indicate that besides its well-known participation in retrieval and early consolidation, mPFC also modulates the endurance of long-lasting aversive memories regardless of whether formation of the aversive mnemonic trace requires the participation of the hippocampus. PMID:25506318

  17. Medial prefrontal cortex dopamine controls the persistent storage of aversive memories

    Directory of Open Access Journals (Sweden)

    María Carolina Gonzalez

    2014-11-01

    Full Text Available Medial prefrontal cortex (mPFC is essential for initial memory processing and expression but its involvement in persistent memory storage has seldom been studied. Using the hippocampus dependent inhibitory avoidance learning task and the hippocampus-independent conditioned taste aversion paradigm together with specific dopamine receptor agonists and antagonists we found that persistence but not formation of long-tem aversive memories requires dopamine D1/D5 receptors activation in mPFC immediately after training and, depending on the task, between 6 and 12 hour later. Our results indicate that besides its well-known participation in retrieval and early consolidation, mPFC also modulates the endurance of long-lasting aversive memories regardless of whether formation of the aversive mnemonic trace requires the participation of the hippocampus.

  18. Medial prefrontal cortex dopamine controls the persistent storage of aversive memories.

    Science.gov (United States)

    Gonzalez, María C; Kramar, Cecilia P; Tomaiuolo, Micol; Katche, Cynthia; Weisstaub, Noelia; Cammarota, Martín; Medina, Jorge H

    2014-01-01

    Medial prefrontal cortex (mPFC) is essential for initial memory processing and expression but its involvement in persistent memory storage has seldom been studied. Using the hippocampus dependent inhibitory avoidance learning task and the hippocampus-independent conditioned taste aversion paradigm together with specific dopamine receptor agonists and antagonists we found that persistence but not formation of long-term aversive memories requires dopamine D1/D5 receptors activation in mPFC immediately after training and, depending on the task, between 6 and 12 h later. Our results indicate that besides its well-known participation in retrieval and early consolidation, mPFC also modulates the endurance of long-lasting aversive memories regardless of whether formation of the aversive mnemonic trace requires the participation of the hippocampus. PMID:25506318

  19. Nonassociative and associative modification of head-waving produced by aversive tentacular stimuli in Aplysia.

    Science.gov (United States)

    Fitzgerald, K K; Takacs, C A; Carew, T J

    1997-01-01

    Head-waving, a spontaneously occurring exploratory and appetitive behavior of the marine mollusc Aplysia, provides an opportunity to examine mechanisms of learning expressed in a nonreflexive behavior. The present study explores nonassociative and associative forms of learned modification of head-waving produced using an aversive stimulus as reinforcement. Experiments on intact, freely behaving animals demonstrate that training with electric shock as an aversive unconditioned stimulus, delivered unilaterally to the anterior tentacles, produces a learned shift in head-waving behavior away from the side on which shock was applied. This behavioral change is a novel learned behavioral response that is influenced by the topographic location of an aversive stimulus. Furthermore, training with application of tentacle shock reinforcement, contingent upon the animal's head position, produces operant conditioning of head-waving. Thus, anterior tentacle shock is effective as an aversive reinforcer for both nonassociative and operant learning expressed in the head-waving behavior of Aplysia. PMID:10456104

  20. Conditioned Flavor Aversion: A Mechanism for Goats to Avoid Condensed Tannins in Blackbrush

    OpenAIRE

    Provenza, Frederick D; Burritt, Elizabeth A; Clausen, T. P.; Bryant, J. P.; Reichardt, P. B.; Distel, Roberto A.

    1990-01-01

    It has been hypothesized that herbivores instinctively avoid tannin-containing plant parts in response to the adverse effects of tannins on forage digestion. However, we found that goats learned to avoid condensed tannins (CTs) from blackbrush current season's growth by associating the flavor of foods containing CTs with aversive postingestive consequences. The aversive consequences experienced by goats apparently are not related to digestion inhibition and may depend on the structure ...

  1. Fetal Protection : The Roles of Social Learning and Innate Food Aversions in South India.

    Science.gov (United States)

    Placek, Caitlyn D; Hagen, Edward H

    2015-09-01

    Pregnancy involves puzzling aversions to nutritious foods. Although studies generally support the hypotheses that such aversions are evolved mechanisms to protect the fetus from toxins and/or pathogens, other factors, such as resource scarcity and psychological distress, have not been investigated as often. In addition, many studies have focused on populations with high-quality diets and low infectious disease burden, conditions that diverge from the putative evolutionary environment favoring fetal protection mechanisms. This study tests the fetal protection, resource scarcity, and psychological distress hypotheses of food aversions in a resource-constrained population with high infectious disease burden. The role of culture is also explored. In the first of two studies in Tamil Nadu, India, we investigated cultural explanations of pregnancy diet among non-pregnant women (N = 54). In the second study, we conducted structured interviews with pregnant women (N = 94) to determine their cravings and aversions, resource scarcity, indices of pathogen exposure, immune activation, psychological distress, and emic causes of aversions. Study 1 found that fruits were the most commonly reported food that pregnant women should avoid because of their harmful effects on infants. Study 2 found modest support for the fetal protection hypothesis for food aversions. It also found that pregnant women most commonly avoided fruits as well as "black" and "hot" foods. Aversions were primarily acquired through learning and focused on protecting the infant from harm. Our findings provide modest support for the fetal protection hypothesis and surprisingly strong support for the influence of cultural norms and learning on dietary aversions in pregnancy. PMID:26286435

  2. Conditioned taste aversion: modulation by 5-HT receptor activity and corticosterone

    DEFF Research Database (Denmark)

    Boris, Gorzalka; Hanson, Laura; Harrington, J;

    2003-01-01

    Two experiments were designed to elucidate the involvement of the hypothalamic-pituitary-adrenal axis and the 5-hydroxytryptamine (5-HT) system in the acquisition of lithium chloride-conditioned taste aversion. In Experiment 1, rats were administered either vehicle or 50 mg/kg nefazodone daily fo......, corticosterone-treated animals required more trials to reach extinction. These results suggest the involvement of both the 5-HT system and the hypothalamic-pituitary-adrenal axis in lithium chloride-conditioned taste aversion....

  3. Risk aversion and adoption of Conservation Agriculture Practices in Eastern Uganda

    OpenAIRE

    Weixler-Landis, Barry

    2014-01-01

    Many poor farmers, especially in Africa, have not adopted recent farming innovations to improve their yields. One theory is that poor farmers are risk averse and therefore do not invest in high risk high return innovations and that risk averse farmers will only adopt larger innovations if they experience success with small ones. Risk preferences were measured in two districts in Uganda (Tororo and Kapchorwa) where adoption of agricultural innovations has been slow, and where a program is unde...

  4. Bupropion Differentially Alters the Aversive, Locomotor and Rewarding Properties of Nicotine in CD-1 Mice

    OpenAIRE

    Rauhut, Anthony S.; Hawrylak, Michael; Mardekian, Stacey K.

    2008-01-01

    The present experiments determined the effects of bupropion on the motivational (aversive and rewarding) and locomotor properties of nicotine in CD-1 mice. Preliminary experiments determined effective nicotine doses (0.1 – 2.0 mg/kg) to produce a conditioned taste aversion (CTA) or conditioned place preference (CPP; Experiments 1a and 2a, respectively). Mice were administered vehicle or bupropion (1 – 20 mg/kg) followed by vehicle or nicotine after drinking saccharin during CTA training (Expe...

  5. A Linear Relationship between Market Prices of Risks and Risk Aversion in Complete Stochastic Volatility Models

    OpenAIRE

    Qian Han

    2013-01-01

    Considering a production economy with an arbitrary von-Neumann Morgenstern utility, this paper derives a general equilibrium relationship between the market prices of risks and market risk aversion under a continuous time stochastic volatility model completed by liquidly traded options. The derived relation shows that in equilibrium the risk aversion should be a linear combination of the market price of asset risk and market price of orthogonal risk. Construction of a daily market risk aversi...

  6. Cognitive function is associated with risk aversion in community-based older persons

    Directory of Open Access Journals (Sweden)

    Buchman Aron S

    2011-09-01

    Full Text Available Abstract Background Emerging data from younger and middle-aged persons suggest that cognitive ability is negatively associated with risk aversion, but this association has not been studied among older persons who are at high risk of experiencing loss of cognitive function. Methods Using data from 369 community-dwelling older persons without dementia from the Rush Memory and Aging Project, an ongoing longitudinal epidemiologic study of aging, we examined the correlates of risk aversion and tested the hypothesis that cognition is negatively associated with risk aversion. Global cognition and five specific cognitive abilities were measured via detailed cognitive testing, and risk aversion was measured using standard behavioral economics questions in which participants were asked to choose between a certain monetary payment ($15 versus a gamble in which they could gain more than $15 or gain nothing; potential gamble gains ranged from $21.79 to $151.19 with the gain amounts varied randomly over questions. We first examined the bivariate associations of age, education, sex, income and cognition with risk aversion. Next, we examined the associations between cognition and risk aversion via mixed models adjusted for age, sex, education, and income. Finally, we conducted sensitivity analyses to ensure that our results were not driven by persons with preclinical cognitive impairment. Results In bivariate analyses, sex, education, income and global cognition were associated with risk aversion. However, in a mixed effect model, only sex (estimate = -1.49, standard error (SE = 0.39, p i.e., semantic memory, episodic memory, working memory, and perceptual speed; performance on visuospatial abilities was not. Conclusion A lower level of cognitive ability and female sex are associated with greater risk aversion in advanced age.

  7. Dopamine, norepinephrine and serotonin transporter gene deletions differentially alter cocaine-induced taste aversion

    OpenAIRE

    Jones, Jermaine D.; Hall, F. Scott; Uhl, George R; Riley, Anthony L.

    2009-01-01

    Although cocaine is primarily known for its powerful hedonic effects, there is evidence that its affective experience has a notable aversive component that is less well understood. A variety of pharmacological and molecular approaches have implicated enhanced monoamine (MA) neurotransmission in the aversive effects of cocaine. Although numerous studies have yielded data supportive of the role of the monoamines (indirectly and directly), the specific system suggested to be involved differs acr...

  8. Myopic Loss Aversion and House-Money Effect Overseas: an experimental approach

    OpenAIRE

    José L. B. Fernandes; Juan Ignacio Peña; Benjamin M. Tabak

    2006-01-01

    Recent literature has found two behavioral effects - house-money and myopic loss aversion (MLA) - in several experimental designs. We show that although we can find a house-money effect using survey methods this evidence disappears when we study investment decision within a multi-period investment experiment. Loss aversion is found to govern the risk-taking behavior of subjects in dynamic settings, overcoming the house-money effect. These results are robust to experiments conducted in two dif...

  9. Risk Aversion, Over-Confidence and Private Information as Determinants of Majority Thresholds

    OpenAIRE

    ATTANASI Giuseppe; Corazzini, Luca; Georgantzís, Nikolaos; Francesco PASSARELLI

    2010-01-01

    We study, both theoretically and experimentally, the relation between preferred majority thresholds and behavioral traits such as the degree of risk aversion and the subjective confidence on others preferences over the alternative to vote. The main theoretical findings are supported by experimental data. The majority threshold chosen by a subject is positively and significantly correlated with her degree of risk aversion while it is negatively and significantly associated to her confidence on...

  10. Taste-Potentiated Odor Aversion Learning in Rats with Lesions of the Insular Cortex

    OpenAIRE

    Lin, Jian-You; Roman, Christopher; Reilly, Steve

    2009-01-01

    The current study assessed the influence of excitotoxic lesions of the insular cortex (IC) on taste-potentiated odor aversion (TPOA) learning. Water-deprived rats initially received a single odor-toxicosis or odor/taste-toxicosis pairing and were subsequently tested, in separate trials, with the odor and the taste stimulus. Indicating TPOA, neurologically intact rats conditioned with the odor/taste compound stimulus acquired significantly stronger odor aversions than normal rats conditioned w...

  11. Inhibitory Deficits, Delay Aversion and Preschool AD/HD: Implications for the Dual Pathway Model

    OpenAIRE

    Lindy Dalen; Sonuga-Barke, Edmund J. S.; Martin Hall; Bob Remington

    2004-01-01

    The dual pathway model proposes the existence of separate and neurobiologically distinct cognitive (inhibitory and more general executive dysfunction) and motivational (delay aversion) developmental routes to AD/HD. The study reported in this paper explores the relation between inhibitory deficits and delay aversion and their association with AD/HD in a group of three-year-old children. Children identified as having a pre-school equivalent of AD/HD (N=19) and controls (N=19), matched for gend...

  12. Optimal Ordering Policy of a Risk-Averse Retailer Subject to Inventory Inaccuracy

    OpenAIRE

    Lijing Zhu; Ki-Sung Hong; Chulung Lee

    2013-01-01

    Inventory inaccuracy refers to the discrepancy between the actual inventory and the recorded inventory information. Inventory inaccuracy is prevalent in retail stores. It may result in a higher inventory level or poor customer service. Earlier studies of inventory inaccuracy have traditionally assumed risk-neutral retailers whose objective is to maximize expected profits. We investigate a risk-averse retailer within a newsvendor framework. The risk aversion attitude is measured by conditional...

  13. Aversive tension in female adolescents with Anorexia Nervosa: a controlled ecological momentary assessment using smartphones

    OpenAIRE

    Kolar, David R.; Hammerle, Florian; Jenetzky, Ekkehart; Huss, Michael; Bürger, Arne

    2016-01-01

    Background Current models of Anorexia Nervosa (AN) emphasize the role of emotion regulation. Aversive tension, described as a state of intense arousal and negative valence, is considered to be a link between emotional events and disordered eating. Recent research focused only on adult patients, and mainly general emotion regulation traits were studied. However, the momentary occurrence of aversive tension, particularly in adolescents with AN, has not been previously studied. Method 20 female ...

  14. Examining Relationships Between Executive Functioning and Delay Aversion in Attention Deficit Hyperactivity Disorder

    OpenAIRE

    Karalunas, Sarah L.; Huang-Pollock, Cynthia L.

    2011-01-01

    Although motivation and cognition are often examined separately, recent theory suggests that a delay-averse motivational style may negatively impact development of executive functions (EFs), such as working memory (WM) and response inhibition (RI) for children with Attention Deficit Hyperactivity Disorder (ADHD; Sonuga-Barke, 2002). This model predicts that performance on delay aversion and EF tasks should be correlated for school-age children with ADHD. However, tests of these relationships ...

  15. Transparency, Inequity Aversion, and the Dynamics of Peer Pressure in Teams: Theory and Evidence

    OpenAIRE

    Mohnen, Alwine; Pokorny, Kathrin; Sliwka, Dirk

    2008-01-01

    We provide an explanation for peer pressure in teams based on inequity aversion. Analyzing a two-period model with two agents, we find that the effect of inequity aversion strongly depends on the information structure. When contributions are unobservable, agents act as if they were purely selfish. However, when contributions are made transparent at an interim stage, agents exert higher efforts in the first period and adjust their efforts according to the interim information in the second peri...

  16. How do working-memory-related demand, reasoning ability and aversive reinforcement modulate conflict monitoring?

    Directory of Open Access Journals (Sweden)

    Anja Leue

    2014-04-01

    Full Text Available Conflict monitoring is a process of stimulus evaluation and a pre-requisite for subsequent recruitment of cognitive control and behavioral adaptations. This study investigated how experimentally manipulated working-memory-related cognitive demand and aversive reinforcement modulate individual differences of conflict monitoring intensity and behavioral adjustments. Individual differences were assessed by means of an anxiety-related trait dimension (trait-BIS and by means of reasoning abilities–a core determinant of intelligence. Moreover, we investigated the special role of verbal reasoning ability and figural reasoning ability for the modulation of the conflict monitoring intensity. Ninety participants performed a go/nogo task with four conditions each comprising a combination of low vs. high working-memory-related cognitive demand and low vs. high aversive reinforcement. No effect of aversive reinforcement was observed for the N2 amplitude. The fronto-central nogo N2 amplitude was more pronounced for high demand vs. low demand suggesting that cognitive demand served as an aversive costly event. Higher total reasoning abilities were associated with more intense conflict monitoring and shorter response times with increasing aversive reinforcement (defined as verbal error-feedback vs. monetary loss. Individuals with higher trait-BIS scores demonstrated a more intense conflict monitoring even in conditions with low aversive reinforcement and also a more cautious responding (i.e., response times slowing with increasing aversive reinforcement indicating a focus on negative feedback prevention. The findings provide evidence for the conflict-monitoring theory and suggest that working-memory-related demand overrules the impact of aversive reinforcement on conflict monitoring intensity. Reasoning abilities and anxiety-related traits go along with an intensification of conflict monitoring but differences in the flexibility of behavioral adjustment.

  17. Dissecting the Serotonergic Food Signal Stimulating Sensory-Mediated Aversive Behavior in C. elegans

    OpenAIRE

    Harris, Gareth; Korchnak, Amanda; Summers, Philip; Hapiak, Vera; Law, Wen Jing; Stein, Andrew M.; Komuniecki, Patricia; Komuniecki, Richard

    2011-01-01

    Nutritional state often modulates olfaction and in Caenorhabditis elegans food stimulates aversive responses mediated by the nociceptive ASH sensory neurons. In the present study, we have characterized the role of key serotonergic neurons that differentially modulate aversive behavior in response to changing nutritional status. The serotonergic NSM and ADF neurons play antagonistic roles in food stimulation. NSM 5-HT activates SER-5 on the ASHs and SER-1 on the RIA interneurons and stimulates...

  18. Serotonin selectively influences moral judgment and behavior through effects on harm aversion

    OpenAIRE

    Crockett, Molly J.; Clark, Luke; Hauser, Marc D.; Robbins, Trevor W.

    2010-01-01

    Aversive emotional reactions to real or imagined social harms infuse moral judgment and motivate prosocial behavior. Here, we show that the neurotransmitter serotonin directly alters both moral judgment and behavior through increasing subjects’ aversion to personally harming others. We enhanced serotonin in healthy volunteers with citalopram (a selective serotonin reuptake inhibitor) and contrasted its effects with both a pharmacological control treatment and a placebo on tests of moral judgm...

  19. Does the kappa opioid receptor system contribute to pain aversion?

    Directory of Open Access Journals (Sweden)

    Catherine M Cahill

    2014-11-01

    Full Text Available The kappa opioid receptor (KOR and the endogenous peptide-ligand dynorphin have received significant attention due the involvement in mediating a variety of behavioral and neurophysiological responses, including opposing the rewarding properties of drugs of abuse including opioids. Accumulating evidence indicates this system is involved in regulating states of motivation and emotion. Acute activation of the KOR produces an increase in motivational behavior to escape a threat, however, KOR activation associated with chronic stress leads to the expression of symptoms indicative of mood disorders. It is well accepted that KOR can produce analgesia and is engaged in chronic pain states including neuropathic pain. Spinal studies have revealed KOR-induced analgesia in reversing pain hypersensitivities associated with peripheral nerve injury. While systemic administration of KOR agonists attenuates nociceptive sensory transmission, this effect appears to be a stress-induced effect as anxiolytic agents, including delta opioid receptor agonists, mitigate KOR agonist-induced analgesia. Additionally, while the role of KOR and dynorphin in driving the dysphoric and aversive components of stress and drug withdrawal has been well characterized, how this system mediates the negative emotional states associated with chronic pain is relatively unexplored. This review provides evidence that dynorphin and the KOR system contribute to the negative affective component of pain and that this receptor system likely contributes to the high comorbidity of mood disorders associated with chronic neuropathic pain.

  20. Lack of insula reactivity to aversive stimuli in schizophrenia.

    Science.gov (United States)

    Linnman, Clas; Coombs, Garth; Goff, Donald C; Holt, Daphne J

    2013-01-01

    Patients with schizophrenia may have altered pain perception, as suggested by clinical reports of pain insensitivity, and recent neuroimaging findings. Here, we examined neural responses to an aversive electrical stimulus and the immediate anticipation of such a stimulus using fMRI and a classical conditioning paradigm, which involved pairing an electrical shock with a neutral photograph. Fifteen men with schizophrenia and 13 healthy men, matched for demographic characteristics, electrical stimulation level and scan movement, were studied. The shock induced robust responses in midbrain, thalamus, cingulate gyrus, insula and somatosensory cortex in both groups. However, compared to controls, the schizophrenic patients displayed significantly lower activation of the middle insula (p(FWE)=0.002, T=5.72, cluster size=24 voxels). Moreover, the lack of insula reactivity in the schizophrenia group was predicted by the magnitude of positive symptoms (r=-0.46, p=0.04). In contrast, there were no significant differences between the two groups in the magnitude of neural responses during anticipation of the shock. These findings provide support for the existence of a basic deficit in interoceptive perception in schizophrenia, which could play a role in the generation and/or maintenance of psychotic states. PMID:23201307

  1. Noxious facility impact projection: Incorporating the effects of risk aversion

    International Nuclear Information System (INIS)

    Developing new sites for noxious facilities has become a complex process with many potential pitfalls. In addition to the need to negotiate conditions acceptable to the host community, siting success may depend on the facility proposer's ability to identify a candidate site that not only meets technical requirements, but that is located in a community or region whose population is not highly averse to the risks associated with the type of facility being proposed. Success may also depend on the proposer accurately assessing potential impacts of the facility and offering an equitable compensation package to the people affected by it. Facility impact assessments, as typically performed, include only the effects of changes in population, employment and economic activity associated with facility construction and operation. Because of their scope, such assessments usually show a short-run, net economic benefit for the host region, making the intensely negative public reaction to some types and locations of facilities seem unreasonable. The impact component excluded from these assessments is the long-run economic effect of public perceptions of facility risk and nuisance characteristics. Recent developments in psychological and economic measurement techniques have opened the possibility of correcting this flaw by incorporating public perceptions in projections of economic impacts from noxious facilities

  2. Economic decisions for others: an exception to loss aversion law.

    Directory of Open Access Journals (Sweden)

    Flavia Mengarelli

    Full Text Available In everyday life, people often make decisions on behalf of others. The current study investigates whether risk preferences of decision-makers differ when the reference point is no longer their own money but somebody else money. Thirty four healthy participants performed three different monetary risky choices tasks by making decisions for oneself and for another unknown person. Results showed that loss aversion bias was significantly reduced when participants were choosing on behalf of another person compared to when choosing for themselves. The influence of emotions like regret on decision-making may explain these results. We discuss the importance of the sense of responsibility embodied in the emotion of regret in modulating economic decisions for self but not for others. Moreover, our findings are consistent with the Risk-as-feelings hypothesis, suggesting that self-other asymmetrical behavior is due to the extent the decision-maker is affected by the real and emotional consequences of his/her decision.

  3. Measuring Risk Aversion for Nuclear Power Plant Accident: Results of Contingent Valuation Survey in Korea

    International Nuclear Information System (INIS)

    Within the evaluation of the external cost of nuclear energy, the estimation of the external cost of nuclear power plant (NPP) severe accident is one of the major topics to be addressed. For the evaluation of the external cost of NPP severe accident, the effect of public risk averse behavior against the group accidents, such as NPP accident, dam failure, must be addressed. Although the equivalent fatalities from a single group accident are not common and its risk is very small compared to other accidents, people perceive the group accident more seriously. In other words, people are more concerned about low probability/high consequence events than about high probability/low consequence events having the same mean damage. One of the representative method to integrate the risk aversion in the external costs of severe nuclear reactor accidents was developed by Eeckoudt et al., and he used the risk aversion coefficient, mainly based on the analysis of financial risks in the stock markets to evaluate the external cost of nuclear severe accident. However, the use of financial risk aversion coefficient to nuclear severe accidents is not appropriate, because financial risk and nuclear severe accident risk are entirely different. In this paper, the individual-level survey was conducted to measure the risk aversion coefficient and estimate the multiplication factor to integrate the risk aversion in the external costs of NPP severe accident. This study propose an integrated framework on estimation of the external cost associated with severe accidents of NPP considering public risk aversion behavior. The theoretical framework to estimate the risk aversion coefficient/multiplication factor and to assess economic damages from a hypothetical NPP accident was constructed. Based on the theoretical framework, the risk aversion coefficient can be analyzed by conducting public survey with a carefully designed lottery questions. Compared to the previous studies on estimation of the

  4. Measuring Risk Aversion for Nuclear Power Plant Accident: Results of Contingent Valuation Survey in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hun; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Within the evaluation of the external cost of nuclear energy, the estimation of the external cost of nuclear power plant (NPP) severe accident is one of the major topics to be addressed. For the evaluation of the external cost of NPP severe accident, the effect of public risk averse behavior against the group accidents, such as NPP accident, dam failure, must be addressed. Although the equivalent fatalities from a single group accident are not common and its risk is very small compared to other accidents, people perceive the group accident more seriously. In other words, people are more concerned about low probability/high consequence events than about high probability/low consequence events having the same mean damage. One of the representative method to integrate the risk aversion in the external costs of severe nuclear reactor accidents was developed by Eeckoudt et al., and he used the risk aversion coefficient, mainly based on the analysis of financial risks in the stock markets to evaluate the external cost of nuclear severe accident. However, the use of financial risk aversion coefficient to nuclear severe accidents is not appropriate, because financial risk and nuclear severe accident risk are entirely different. In this paper, the individual-level survey was conducted to measure the risk aversion coefficient and estimate the multiplication factor to integrate the risk aversion in the external costs of NPP severe accident. This study propose an integrated framework on estimation of the external cost associated with severe accidents of NPP considering public risk aversion behavior. The theoretical framework to estimate the risk aversion coefficient/multiplication factor and to assess economic damages from a hypothetical NPP accident was constructed. Based on the theoretical framework, the risk aversion coefficient can be analyzed by conducting public survey with a carefully designed lottery questions. Compared to the previous studies on estimation of the

  5. Common brain activations for painful and non-painful aversive stimuli

    Directory of Open Access Journals (Sweden)

    Hayes Dave J

    2012-06-01

    Full Text Available Abstract Background Identification of potentially harmful stimuli is necessary for the well-being and self-preservation of all organisms. However, the neural substrates involved in the processing of aversive stimuli are not well understood. For instance, painful and non-painful aversive stimuli are largely thought to activate different neural networks. However, it is presently unclear whether there is a common aversion-related network of brain regions responsible for the basic processing of aversive stimuli. To help clarify this issue, this report used a cross-species translational approach in humans (i.e. meta-analysis and rodents (i.e. systematic review of functional neuroanatomy. Results Animal and human data combined to show a core aversion-related network, consisting of similar cortical (i.e. MCC, PCC, AI, DMPFC, RTG, SMA, VLOFC; see results section or abbreviation section for full names and subcortical (i.e. Amyg, BNST, DS, Hab, Hipp/Parahipp, Hyp, NAc, NTS, PAG, PBN, raphe, septal nuclei, Thal, LC, midbrain regions. In addition, a number of regions appeared to be more involved in pain-related (e.g. sensory cortex or non-pain-related (e.g. amygdala aversive processing. Conclusions This investigation suggests that aversive processing, at the most basic level, relies on similar neural substrates, and that differential responses may be due, in part, to the recruitment of additional structures as well as the spatio-temporal dynamic activity of the network. This network perspective may provide a clearer understanding of why components of this circuit appear dysfunctional in some psychiatric and pain-related disorders.

  6. Neural systems underlying aversive conditioning in humans with primary and secondary reinforcers

    Directory of Open Access Journals (Sweden)

    Mauricio R Delgado

    2011-05-01

    Full Text Available Money is a secondary reinforcer commonly used across a range of disciplines in experimental paradigms investigating reward learning and decision-making. The effectiveness of monetary reinforcers during aversive learning and its neural basis, however, remains a topic of debate. Specifically, it is unclear if the initial acquisition of aversive representations of monetary losses depends on similar neural systems as more traditional aversive conditioning that involves primary reinforcers. This study contrasts the efficacy of a biologically defined primary reinforcer (shock and a socially defined secondary reinforcer (money during aversive learning and its associated neural circuitry. During a two-part experiment, participants first played a gambling game where wins and losses were based on performance to gain an experimental bank. Participants were then exposed to two separate aversive conditioning sessions. In one session, a primary reinforcer (mild shock served as an unconditioned stimulus (US and was paired with one of two colored squares, the conditioned stimuli (CS+ and CS-, respectively. In another session, a secondary reinforcer (loss of money served as the US and was paired with one of two different CS. Skin conductance responses were greater for CS+ compared to CS- trials irrespective of type of reinforcer. Neuroimaging results revealed that the striatum, a region typically linked with reward-related processing, was found to be involved in the acquisition of aversive conditioned response irrespective of reinforcer type. In contrast, the amygdala was involved during aversive conditioning with primary reinforcers, as suggested by both an exploratory fMRI analysis and a follow-up case study with a patient with bilateral amygdala damage. Taken together, these results suggest that learning about potential monetary losses may depend on reinforcement learning related systems, rather than on typical structures involved in more biologically based

  7. Psychophysical and Neural Correlates of Auditory Attraction and Aversion

    Science.gov (United States)

    Patten, Kristopher Jakob

    This study explores the psychophysical and neural processes associated with the perception of sounds as either pleasant or aversive. The underlying psychophysical theory is based on auditory scene analysis, the process through which listeners parse auditory signals into individual acoustic sources. The first experiment tests and confirms that a self-rated pleasantness continuum reliably exists for 20 various stimuli (r = .48). In addition, the pleasantness continuum correlated with the physical acoustic characteristics of consonance/dissonance (r = .78), which can facilitate auditory parsing processes. The second experiment uses an fMRI block design to test blood oxygen level dependent (BOLD) changes elicited by a subset of 5 exemplar stimuli chosen from Experiment 1 that are evenly distributed over the pleasantness continuum. Specifically, it tests and confirms that the pleasantness continuum produces systematic changes in brain activity for unpleasant acoustic stimuli beyond what occurs with pleasant auditory stimuli. Results revealed that the combination of two positively and two negatively valenced experimental sounds compared to one neutral baseline control elicited BOLD increases in the primary auditory cortex, specifically the bilateral superior temporal gyrus, and left dorsomedial prefrontal cortex; the latter being consistent with a frontal decision-making process common in identification tasks. The negatively-valenced stimuli yielded additional BOLD increases in the left insula, which typically indicates processing of visceral emotions. The positively-valenced stimuli did not yield any significant BOLD activation, consistent with consonant, harmonic stimuli being the prototypical acoustic pattern of auditory objects that is optimal for auditory scene analysis. Both the psychophysical findings of Experiment 1 and the neural processing findings of Experiment 2 support that consonance is an important dimension of sound that is processed in a manner that aids

  8. Impaired conditioned taste aversion learning in spinophilin knockout mice.

    Science.gov (United States)

    Stafstrom-Davis, C A; Ouimet, C C; Feng, J; Allen, P B; Greengard, P; Houpt, T A

    2001-01-01

    Plasticity in dendritic spines may underlie learning and memory. Spinophilin, a protein enriched in dendritic spines, has the properties of a scaffolding protein and is believed to regulate actin cytoskeletal dynamics affecting dendritic spine morphology. It also binds protein phosphatase-1 (PP-1), an enzyme that regulates dendritic spine physiology. In this study, we tested the role of spinophilin in conditioned taste aversion learning (CTA) using transgenic spinophilin knockout mice. CTA is a form of associative learning in which an animal rejects a food that has been paired previously with a toxic effect (e.g., a sucrose solution paired with a malaise-inducing injection of lithium chloride). Acquisition and extinction of CTA was tested in spinophilin knockout and wild-type mice using taste solutions (sucrose or sodium chloride) or flavors (Kool-Aid) paired with moderate or high doses of LiCl (0.15 M, 20 or 40 mL/kg). When sucrose or NaCl solutions were paired with a moderate dose of LiCl, spinophilin knockout mice were unable to learn a CTA. At the higher dose, knockout mice acquired a CTA but extinguished more rapidly than wild-type mice. A more salient flavor stimulus (taste plus odor) revealed similar CTA learning at both doses of LiCl in both knockouts and wild types. Sensory processing in the knockouts appeared normal because knockout mice and wild-type mice expressed identical unconditioned taste preferences in two-bottle tests, and identical lying-on-belly responses to acute LiCl. We conclude that spinophilin is a candidate molecule required for normal CTA learning. PMID:11584074

  9. Electricity capacity investment under risk aversion: A case study of coal, gas, and concentrated solar power

    International Nuclear Information System (INIS)

    The policy instrument many economists favor to reduce greenhouse gas emissions and to shift new investment towards low carbon technologies is the tradable allowance system. Experience with this instrument has been mixed, with a crucial design issue being the choice of whether to auction allowances to firms, or to grandfather them based on historical emissions. In this paper, we examine the changing incentives of investment in different technologies, when investors are risk averse and are expecting an allowance system with a certain allocation rule but do not know if the policy is going to take place in the near future. Investors also cannot fully predict future investment costs for the low-carbon technology. We apply a game theoretic model to examine the combined effects of uncertainty and risk aversion on the actions of potential investors into high and low carbon generating capacity, under both allocation rules and uncertain costs. We find that uncertainty and risk aversion do have implications towards investment incentives. We discuss policy implications of these findings. - Highlights: ► We examined capacity investments under alternative carbon permit allocation schemes. ► Uncertainty in future permit markets’ existence reduces investments into renewables. ► If permits are grandfathered, risk averse companies decrease renewable investment. ► Risk aversion minimizes the effects of uncertainty if carbon permits are auctioned.

  10. Genotypic influence on aversive conditioning in honeybees, using a novel thermal reinforcement procedure.

    Directory of Open Access Journals (Sweden)

    Pierre Junca

    Full Text Available In Pavlovian conditioning, animals learn to associate initially neutral stimuli with positive or negative outcomes, leading to appetitive and aversive learning respectively. The honeybee (Apis mellifera is a prominent invertebrate model for studying both versions of olfactory learning and for unraveling the influence of genotype. As a queen bee mates with about 15 males, her worker offspring belong to as many, genetically-different patrilines. While the genetic dependency of appetitive learning is well established in bees, it is not the case for aversive learning, as a robust protocol was only developed recently. In the original conditioning of the sting extension response (SER, bees learn to associate an odor (conditioned stimulus - CS with an electric shock (unconditioned stimulus - US. This US is however not a natural stimulus for bees, which may represent a potential caveat for dissecting the genetics underlying aversive learning. We thus first tested heat as a potential new US for SER conditioning. We show that thermal stimulation of several sensory structures on the bee's body triggers the SER, in a temperature-dependent manner. Moreover, heat applied to the antennae, mouthparts or legs is an efficient US for SER conditioning. Then, using microsatellite analysis, we analyzed heat sensitivity and aversive learning performances in ten worker patrilines issued from a naturally inseminated queen. We demonstrate a strong influence of genotype on aversive learning, possibly indicating the existence of a genetic determinism of this capacity. Such determinism could be instrumental for efficient task partitioning within the hive.

  11. Conditioned taste aversion in rats exposed to 2450 MHz CW microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Williams, W.; Michaelson, S.M.

    1978-01-01

    The ability of 2450 MHz CW microwaves to induce an aversive response to saccharin was investigated in rats subjected to the following exposure parameters: incident power densities of 10 to 65 mW/cm/sup 2/ for 10 minutes; 20 mW/cm/sup 2/ for 2 hours; and 65 mW/cm/sup 2/ continuously for 1 hour. Sham-irradiated controls were tested simultaneously. Core body temperatures were measured using a rectal probe before and after microwave exposure. Only those animals irradiated continuously at 65 mW/cm/sup 2/ for 1 hour responded with a significantly reduced saccharin intake. The aversive response correlated with a rise of core body temperature to 39.8/sup 0/C or higher. While taste aversions following administration of apomorphine are considered to be the result of gastrointestinal disturbances, such disturbance does not appear to be the primary cause for microwave-induced aversion. More likely, it appears that exposure to certain levels of microwave irradiation induces a stress that is hyperthermic in nature. What effect this hyperthermic condition has on gastrointestinal and biochemical processes cannot be assessed at this time. It appears, however, that when core body temperature is raised to approximately 40/sub 0/C or higher for one hour or more, the physiological and behavioral temperature regulating mechanisms of the animal become sufficiently stressed to produce the observed taste aversion.

  12. Twins less frequent than expected among male births in risk averse populations.

    Science.gov (United States)

    Karasek, Deborah; Goodman, Julia; Gemmill, Alison; Falconi, April; Hartig, Terry; Magganas, Aristotle; Catalano, Ralph

    2015-06-01

    Male twin gestations exhibit higher incidence of fetal morbidity and mortality than singleton gestations. From an evolutionary perspective, the relatively high rates of infant and child mortality among male twins born into threatening environments reduce the fitness of these gestations, making them more vulnerable to fetal loss. Women do not perceive choosing to spontaneously abort gestations although the outcome may result from estimates, made without awareness, of the risks of continuing a pregnancy. Here, we examine whether the non-conscious decisional biology of gestation can be linked to conscious risk aversion. We test this speculation by measuring the association between household surveys in Sweden that gauge financial risk aversion in the population and the frequency of twins among live male births. We used time-series regression methods to estimate our suspected associations and Box-Jenkins modeling to ensure that autocorrelation did not confound the estimation or reduce its efficiency. We found, consistent with theory, that financial risk aversion in the population correlates inversely with the odds of a twin among Swedish males born two months later. The odds of a twin among males fell by approximately 3.5% two months after unexpectedly great risk aversion in the population. This work implies that shocks that affect population risk aversion carry implications for fetal loss in vulnerable twin pregnancies. PMID:25917386

  13. Aversive learning in honeybees revealed by the olfactory conditioning of the sting extension reflex.

    Directory of Open Access Journals (Sweden)

    Vanina Vergoz

    Full Text Available Invertebrates have contributed greatly to our understanding of associative learning because they allow learning protocols to be combined with experimental access to the nervous system. The honeybee Apis mellifera constitutes a standard model for the study of appetitive learning and memory since it was shown, almost a century ago, that bees learn to associate different sensory cues with a reward of sugar solution. However, up to now, no study has explored aversive learning in bees in such a way that simultaneous access to its neural bases is granted. Using odorants paired with electric shocks, we conditioned the sting extension reflex, which is exhibited by harnessed bees when subjected to a noxious stimulation. We show that this response can be conditioned so that bees learn to extend their sting in response to the odorant previously punished. Bees also learn to extend the proboscis to one odorant paired with sugar solution and the sting to a different odorant paired with electric shock, thus showing that they can master both appetitive and aversive associations simultaneously. Responding to the appropriate odorant with the appropriate response is possible because two different biogenic amines, octopamine and dopamine subserve appetitive and aversive reinforcement, respectively. While octopamine has been previously shown to substitute for appetitive reinforcement, we demonstrate that blocking of dopaminergic, but not octopaminergic, receptors suppresses aversive learning. Therefore, aversive learning in honeybees can now be accessed both at the behavioral and neural levels, thus opening new research avenues for understanding basic mechanisms of learning and memory.

  14. Growth Hormone Therapy Is Safe and Effective in Patients with Lysinuric Protein Intolerance

    OpenAIRE

    Niinikoski, Harri; Lapatto, Risto; Nuutinen, Matti; Tanner, Laura; Simell, Olli; Näntö-Salonen, Kirsti

    2011-01-01

    Background: Lysinuric protein intolerance (LPI) is an autosomal recessive cationic amino acid transport defect characterized by episodes of postprandial hyperammonemias and spontaneous protein aversion. Subnormal growth is common in spite of appropriate nutritional therapy. Growth hormone (GH) therapy promotes appetite, protein synthesis and accretion, but its possible growth-promoting effects and safety in patients with LPI are poorly known.

  15. A psychological law of inertia and the illusion of loss aversion

    Directory of Open Access Journals (Sweden)

    David Gal

    2006-07-01

    Full Text Available The principle of loss aversion is thought to explain a wide range of anomalous phenomena involving tradeoffs between losses and gains. In this article, I show that the anomalies loss aversion was introduced to explain --- the risky bet premium, the endowment effect, and the status-quo bias --- are characterized not only by a loss/gain tradeoff, but by a tradeoff between the status-quo and change; and, that a propensity towards the status-quo in the latter tradeoff is sufficient to explain these phenomena. Moreover, I show that two basic psychological principles --- (1 that motives drive behavior; and (2 that preferences tend to be fuzzy and ill-defined --- imply the existence of a robust and fundamental propensity of this sort. Thus, a loss aversion principle is rendered superfluous to an account of the phenomena it was

  16. Estimating risk aversion, Risk-Neutral and Real-World Densities using Brazilian Real currency options

    Directory of Open Access Journals (Sweden)

    José Fajardo

    2012-12-01

    Full Text Available This paper uses the Liu et al. (2007 approach to estimate the optionimplied Risk-Neutral Densities (RND, real-world density (RWD, and relative risk aversion from the Brazilian Real/US Dollar exchange rate distribution. Our empirical application uses a sample of exchange-traded Brazilian Real currency options from 1999 to 2011. Our estimated value of the relative risk aversion is around 2.7, which is in line with other articles for the Brazilian Economy. Our out-of-sample results showed that the RND has some ability to forecast the Brazilian Real exchange rate, but when we incorporate the risk aversion, the out-of-sample performance improves substantially.

  17. Risk-Averse Evolutionary Game Model of Aviation Joint Emergency Response

    Directory of Open Access Journals (Sweden)

    Wei Pan

    2016-01-01

    Full Text Available We study effects of risk-averse attitude of both participators in aviation joint emergency response on the coevolution of cooperation mechanisms and individual preferences between airport and nonprofit organization. First, based on the current aviation joint emergency mechanism in China, we put forward two mechanisms to select the joint nonprofit organization, including reputation cooperation and bidding competition. Meanwhile, we consider two preferences including altruism and selfishness. Then we build replicator dynamics equations using the theory of conditional value-at-risk (CVaR taking risk aversion attitude into account. Finally, we introduce the factor of government and give all participators some suggestions. We show that the risk-averse attitude of the other game participator affects the one participator’s decision and the effects subject to some parameters.

  18. Serotonin 2A receptors contribute to the regulation of risk-averse decisions

    DEFF Research Database (Denmark)

    Macoveanu, Julian; Rowe, James B; Hornboll, Bettina;

    2013-01-01

    risk-averse choice behavior was abolished by 5-HT2A receptor blockade. The results provide the first evidence for a critical role of 5-HT2A receptor function in regulating risk-averse behavior. We suggest that the 5-HT2A receptor system facilitates risk-taking behavior by modulating the outcome......Pharmacological studies point to a role of the neurotransmitter serotonin (5-HT) in regulating the preference for risky decisions, yet the functional contribution of specific 5-HT receptors remains to be clarified. We used pharmacological fMRI to investigate the role of the 5-HT2A receptors in...... processing negative outcomes and regulating risk-averse behavior. During fMRI, twenty healthy volunteers performed a gambling task under two conditions: with or without blocking the 5-HT2A receptors. The volunteers repeatedly chose between small, likely rewards and large, unlikely rewards. Choices were...

  19. Dopamine Regulates Aversive Contextual Learning and Associated In Vivo Synaptic Plasticity in the Hippocampus.

    Science.gov (United States)

    Broussard, John I; Yang, Kechun; Levine, Amber T; Tsetsenis, Theodoros; Jenson, Daniel; Cao, Fei; Garcia, Isabella; Arenkiel, Benjamin R; Zhou, Fu-Ming; De Biasi, Mariella; Dani, John A

    2016-03-01

    Dopamine release during reward-driven behaviors influences synaptic plasticity. However, dopamine innervation and release in the hippocampus and its role during aversive behaviors are controversial. Here, we show that in vivo hippocampal synaptic plasticity in the CA3-CA1 circuit underlies contextual learning during inhibitory avoidance (IA) training. Immunohistochemistry and molecular techniques verified sparse dopaminergic innervation of the hippocampus from the midbrain. The long-term synaptic potentiation (LTP) underlying the learning of IA was assessed with a D1-like dopamine receptor agonist or antagonist in ex vivo hippocampal slices and in vivo in freely moving mice. Inhibition of D1-like dopamine receptors impaired memory of the IA task and prevented the training-induced enhancement of both ex vivo and in vivo LTP induction. The results indicate that dopamine-receptor signaling during an aversive contextual task regulates aversive memory retention and regulates associated synaptic mechanisms in the hippocampus that likely underlie learning. PMID:26904943

  20. Aversive reinforcement improves visual discrimination learning in free-flying honeybees.

    Directory of Open Access Journals (Sweden)

    Aurore Avarguès-Weber

    Full Text Available BACKGROUND: Learning and perception of visual stimuli by free-flying honeybees has been shown to vary dramatically depending on the way insects are trained. Fine color discrimination is achieved when both a target and a distractor are present during training (differential conditioning, whilst if the same target is learnt in isolation (absolute conditioning, discrimination is coarse and limited to perceptually dissimilar alternatives. Another way to potentially enhance discrimination is to increase the penalty associated with the distractor. Here we studied whether coupling the distractor with a highly concentrated quinine solution improves color discrimination of both similar and dissimilar colors by free-flying honeybees. As we assumed that quinine acts as an aversive stimulus, we analyzed whether aversion, if any, is based on an aversive sensory input at the gustatory level or on a post-ingestional malaise following quinine feeding. METHODOLOGY/PRINCIPAL FINDINGS: We show that the presence of a highly concentrated quinine solution (60 mM acts as an aversive reinforcer promoting rejection of the target associated with it, and improving discrimination of perceptually similar stimuli but not of dissimilar stimuli. Free-flying bees did not use remote cues to detect the presence of quinine solution; the aversive effect exerted by this substance was mediated via a gustatory input, i.e. via a distasteful sensory experience, rather than via a post-ingestional malaise. CONCLUSION: The present study supports the hypothesis that aversion conditioning is important for understanding how and what animals perceive and learn. By using this form of conditioning coupled with appetitive conditioning in the framework of a differential conditioning procedure, it is possible to uncover discrimination capabilities that may remain otherwise unsuspected. We show, therefore, that visual discrimination is not an absolute phenomenon but can be modulated by experience.

  1. Attending to the outcome of others: disadvantageous inequity aversion in male capuchin monkeys (Cebus apella).

    Science.gov (United States)

    Fletcher, Grace E

    2008-09-01

    Brosnan and de Waal [Nature 425:297-299, 2003] reported that capuchin monkeys responded negatively to unequal reward distributions between themselves and another individual when comparing their own rewards with that of their partner. It was suggested that social emotions provided the underlying motivation for such behavior and that this inequity aversion is specific to the social domain. However, alternative hypotheses such as the "frustration effect" or the "food expectation hypothesis" may provide more parsimonious explanations for Brosnan and de Waal's [Nature 425:297-299] results, while others have argued that these findings are not congruent with the Fehr-Schmidt inequity aversion model cited by the authors. The claim that inequity aversion behavior is specific to the social domain has also been questioned, as primates also develop expectations about rewards in the absence of partners, and react negatively when those expectations are violated. In this study, a modified Dictator game was used to investigate whether capuchins would exhibit either disadvantageous inequity aversion behavior or reference-dependent expectancy violation in social and nonsocial conditions, respectively. When given the choice between an equitable and an inequitable outcome, the subjects showed disadvantageous inequity aversion behavior, choosing the equitable outcome significantly more in the social condition. In the nonsocial condition, however, subjects did not show negative expectancy violation resulting from the formation of reference-dependent expectations, choosing the equitable outcome at chance levels. These results suggest that capuchins attend to differential payoffs and that they are averse to inequity, which is disadvantageous to themselves. PMID:18521838

  2. Behavioral architecture of opioid reward and aversion in C57BL/6 substrains

    Directory of Open Access Journals (Sweden)

    Camron D Bryant

    2015-01-01

    Full Text Available Drug liking versus drug disliking is a subjective motivational measure in humans that assesses the addiction liability of drugs. Variation in this trait is hypothesized to influence vulnerability versus resilience toward substance abuse disorders and likely contains a genetic component. In rodents and humans, conditioned place preference (CPP / aversion (CPA is a Pavlovian conditioning paradigm whereby a learned preference for the drug-paired environment is used to infer drug liking whereas a learned avoidance or aversion is used to infer drug disliking. C57BL/6 inbred mouse substrains are nearly genetically identical, yet demonstrate robust differences in addiction-relevant behaviors, including locomotor sensitization to cocaine and consumption of ethanol. Here, we tested the hypothesis that B6 substrains would demonstrate differences in the rewarding properties of the mu opioid receptor agonist oxycodone (5 mg/kg, i.p. and the aversive properties of the opioid receptor antagonist naloxone (4 mg/kg, i.p.. Both substrains showed similar degrees of oxycodone-induced CPP; however, there was a three-fold enhancement of naloxone-induced CPA in agonist-naïve C57BL/6J relative to C57Bl/6NJ mice. Exploratory factor analysis of CPP and CPA identified unique factors that explain variance in behavioral expression of reward versus aversion. “Conditioned Opioid-Like Behavior” was a reward-based factor whereby drug-free locomotor variables resembling opioid treatment co-varied with the degree of CPP. “Avoidance and Freezing” was an aversion-based factor, whereby the increase in the number of freezing bouts co-varied with the degree of aversion. These results provide new insight into the behavioral architecture of the motivational properties of opioids. Future studies will use quantitative trait locus mapping in B6 substrains to identify novel genetic factors that contribute to the marked strain difference in NAL-CPA.

  3. Behavioral architecture of opioid reward and aversion in C57BL/6 substrains.

    Science.gov (United States)

    Kirkpatrick, Stacey L; Bryant, Camron D

    2014-01-01

    Drug liking vs. drug disliking is a subjective motivational measure in humans that assesses the addiction liability of drugs. Variation in this trait is hypothesized to influence vulnerability vs. resilience toward substance abuse disorders and likely contains a genetic component. In rodents and humans, conditioned place preference (CPP)/aversion (CPA) is a Pavlovian conditioning paradigm whereby a learned preference for the drug-paired environment is used to infer drug liking whereas a learned avoidance or aversion is used to infer drug disliking. C57BL/6 inbred mouse substrains are nearly genetically identical, yet demonstrate robust differences in addiction-relevant behaviors, including locomotor sensitization to cocaine and consumption of ethanol. Here, we tested the hypothesis that B6 substrains would demonstrate differences in the rewarding properties of the mu opioid receptor agonist oxycodone (5 mg/kg, i.p.) and the aversive properties of the opioid receptor antagonist naloxone (4 mg/kg, i.p.). Both substrains showed similar degrees of oxycodone-induced CPP; however, there was a three-fold enhancement of naloxone-induced CPA in agonist-naïve C57BL/6J relative to C57Bl/6NJ mice. Exploratory factor analysis of CPP and CPA identified unique factors that explain variance in behavioral expression of reward vs. aversion. "Conditioned Opioid-Like Behavior" was a reward-based factor whereby drug-free locomotor variables resembling opioid treatment co-varied with the degree of CPP. "Avoidance and Freezing" was an aversion-based factor, whereby the increase in the number of freezing bouts co-varied with the degree of aversion. These results provide new insight into the behavioral architecture of the motivational properties of opioids. Future studies will use quantitative trait locus mapping in B6 substrains to identify novel genetic factors that contribute to the marked strain difference in NAL-CPA. PMID:25628547

  4. Attenuation and cross-attenuation in taste aversion learning in the rat: Studies with ionizing radiation, lithium chloride and ethanol

    International Nuclear Information System (INIS)

    The preexposure paradigm was utilized to evaluate the similarity of ionizing radiation, lithium chloride and ethanol as unconditioned stimuli for the acquisition of a conditioned taste aversion. Three unpaired preexposures to lithium chloride (3.0 mEq/kg, IP) blocked the acquisition of a taste aversion when a novel sucrose solution was paired with either the injection of the same dose of lithium chloride or exposure to ionizing radiation (100 rad). Similar pretreatment with radiation blocked the acquisition of a radiation-induced aversion, but had no effect on taste aversions produced by lithium chloride (3.0 or 1.5 mEq/kg). Preexposure to ethanol (4 g/kg, PO) disrupted the acquisition of an ethanol-induced taste aversion, but not radiation- or lithium chloride-induced aversions. In contrast, preexposure to either radiation or lithium chloride attenuated an ethanol-induced taste aversion in intact rats, but not in rats with lesions of the area postrema. The results are discussed in terms of relationships between these three unconditioned stimuli and in terms of implications of these results for understanding the nature of the proximal unconditioned stimulus in taste aversion learning

  5. The Effect of Swimming Experience on Acquisition and Retention of Swimming-Based Taste Aversion Learning in Rats

    Science.gov (United States)

    Masaki, Takahisa; Nakajima, Sadahiko

    2010-01-01

    Swimming endows rats with an aversion to a taste solution consumed before swimming. The present study explored whether the experience of swimming before or after the taste-swimming trials interferes with swimming-based taste aversion learning. Experiment 1 demonstrated that a single preexposure to 20 min of swimming was as effective as four or…

  6. Pontine and Thalamic Influences on Fluid Rewards: II. Sucrose and Corn Oil Conditioned Aversions

    OpenAIRE

    Liang, Nu-Chu; Grigson, Patricia S.; Norgren, Ralph

    2011-01-01

    In this study conditioned aversions were produced in sham feeding rats to limit postingestive feedback from the oral stimulus. All control rats learned an aversion to either 100% corn oil or 0.3M sucrose when ingestion of these stimuli was followed by an injection of lithium chloride (LiCl). Rats with lesions of the ventroposteromedial thalamus also learned to avoid either corn oil or sucrose. After 3 trials, rats with damage to the parabrachial nuclei (PBN) learned to avoid 100% corn oil, bu...

  7. Stackelberg Game of Buyback Policy in Supply Chain with a Risk-Averse Retailer and a Risk-Averse Supplier Based on CVaR

    OpenAIRE

    Zhou, Yanju; Chen, Qian; Chen, Xiaohong; Wang, Zongrun

    2014-01-01

    This paper considers a decentralized supply chain in which a single supplier sells a perishable product to a single retailer facing uncertain demand. We assume that the supplier and the retailer are both risk averse and utilize Conditional Value at Risk (CVaR), a risk measure method which is popularized in financial risk management, to estimate their risk attitude. We establish a buyback policy model based on Stackelberg game theory under considering supply chain members' risk preference and ...

  8. Protective immunity of rAd5/NR2B vaccine against concomitant aversiveness of spontaneous neuropathic pain following spinal nerve ligation injury

    OpenAIRE

    Wang, Gong-Ming; Wang, Xiao-Yan; Liu, Guang-Jie; Cheng, Kun; Wang, Hua; Guo, Shou-Gang

    2015-01-01

    Objective: Peripheral nerve injury elicits an aversive state of spontaneous neuropathic pain, and up to now, the modulation of this concomitant aversive state remains a major therapeutic challenge. NMDA receptor subunits NR2B in the rACC are critically involved in the processing of this aversive state and then a strategy targeted at the NR2B subunit might be promising for modulation of the aversive state. Thus, in the present study, using negative reinforcement animal model to reveal spontane...

  9. Neural Correlates of Appetitive-Aversive Interactions in Pavlovian Fear Conditioning

    Science.gov (United States)

    Nasser, Helen M.; McNally, Gavan P.

    2013-01-01

    We used Pavlovian counterconditioning in rats to identify the neural mechanisms for appetitive-aversive motivational interactions. In Stage I, rats were trained on conditioned stimulus (CS)-food (unconditioned stimulus [US]) pairings. In Stage II, this appetitive CS was transformed into a fear CS via pairings with footshock. The development of…

  10. Empirical evidence on risk aversion for individual romanian capital market investors

    Directory of Open Access Journals (Sweden)

    Cristian PAUN

    2008-05-01

    Full Text Available The evolution of stock prices is influenced by the expectations of investors regarding the earning prospects associated to each listed company. One of the key elements of investment decision is the positive relationship between risk and return. Risky securities are preferred to less risky ones only if there is a higher pay-off in the long run that could compensate the investors. The previous studies proved that expected return direct correlated with risk and, due to the presence of risk aversion, this relationship is assumed to be positive one. Risk premium is determined by a lot of factors including risk aversion. The intensity of risk aversion and the evolution of it during a specific period of time are very important for any market. This study proposed an analysis of risk aversion that is based on a specific survey and it is very useful for comparative analysis with other similar studies developed on the case of other emerging markets (from EU or outside EU.

  11. Further Analysis of Variables That Affect Self-Control with Aversive Events

    Science.gov (United States)

    Perrin, Christopher J.; Neef, Nancy A.

    2012-01-01

    The purpose of this study was to examine variables that affect self-control in the context of academic task completion by elementary school children with autism. In the baseline assessment of Study 1, mathematics problem completion was shown to be an aversive event, and sensitivity to task magnitude, task difficulty, and delay to task completion…

  12. Risk-averse and Risk-seeking Investor Preferences for Oil Spot and Futures

    NARCIS (Netherlands)

    H.H. Lean (Hooi Hooi); M.J. McAleer (Michael); W-K. Wong (Wing-Keung)

    2013-01-01

    textabstractThis paper examines risk-averse and risk-seeking investor preferences for oil spot and futures prices by using the mean-variance (MV) criterion and stochastic dominance (SD) approach. The MV findings cannot distinguish between the preferences of spot and futures markets. However, the SD

  13. Serotonin and dopamine in the parabrachial nucleus of rats during conditioned taste aversion learning

    Czech Academy of Sciences Publication Activity Database

    Zach, P.; Křivánek, Jiří; Valeš, Karel

    2006-01-01

    Roč. 170, č. 2 (2006), s. 271-276. ISSN 0166-4328 R&D Projects: GA MŠk(CZ) 1M0517 Institutional research plan: CEZ:AV0Z5011922 Keywords : taste aversion * microdialysis * parabrachial nucleus Subject RIV: FH - Neurology Impact factor: 2.591, year: 2006

  14. Optimal Ordering Policy of a Risk-Averse Retailer Subject to Inventory Inaccuracy

    Directory of Open Access Journals (Sweden)

    Lijing Zhu

    2013-01-01

    Full Text Available Inventory inaccuracy refers to the discrepancy between the actual inventory and the recorded inventory information. Inventory inaccuracy is prevalent in retail stores. It may result in a higher inventory level or poor customer service. Earlier studies of inventory inaccuracy have traditionally assumed risk-neutral retailers whose objective is to maximize expected profits. We investigate a risk-averse retailer within a newsvendor framework. The risk aversion attitude is measured by conditional-value-at-risk (CVaR. We consider inventory inaccuracy stemming both from permanent shrinkage and temporary shrinkage. Two scenarios of reducing inventory shrinkage are presented. In the first scenario, the retailer conducts physical inventory audits to identify the discrepancy. In the second scenario, the retailer deploys an automatic tracking technology, radiofrequency identification (RFID, to reduce inventory shrinkage. With the CVaR criterion, we propose optimal policies for the two scenarios. We show monotonicity between the retailer’s ordering policy and his risk aversion degree. A numerical analysis provides managerial insights for risk-averse retailers considering investing in RFID technology.

  15. Exposure to Sexist Humor and Rape Proclivity: The Moderator Effect of Aversiveness Ratings

    Science.gov (United States)

    Romero-Sanchez, Monica; Duran, Mercedes; Carretero-Dios, Hugo; Megias, Jesus L.; Moya, Miguel

    2010-01-01

    The aim of this study is to explore the effect of exposure to sexist humor about women on men's self-reported rape proclivity. Earlier studies have shown that exposure to this type of humor increases rape proclivity and that funniness responses to jokes are a key element to consider. However, the role of aversiveness responses has not been…

  16. Steroid Hormone (20-Hydroxyecdysone) Modulates the Acquisition of Aversive Olfactory Memories in Pollen Forager Honeybees

    Science.gov (United States)

    Geddes, Lisa H.; McQuillan, H. James; Aiken, Alastair; Vergoz, Vanina; Mercer, Alison R.

    2013-01-01

    Here, we examine effects of the steroid hormone, 20-hydroxyecdysone (20-E), on associative olfactory learning in the honeybee, "Apis mellifera." 20-E impaired the bees' ability to associate odors with punishment during aversive conditioning, but did not interfere with their ability to associate odors with a food reward (appetitive…

  17. Are apes inequity averse? New data on the token-exchange paradigm.

    Science.gov (United States)

    Bräuer, Juliane; Call, Josep; Tomasello, Michael

    2009-02-01

    Recent studies have produced mixed evidence about inequity aversion in nonhuman primates. Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253-258, 2005] found inequity aversion in chimpanzees and argued that effort is crucial, if subjects are to evaluate how they are rewarded in comparison to a competitor for an identical performance. In this study we investigated inequity aversion with chimpanzees, bonobos and orangutans, using the method of Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253-258, 2005] after introducing some methodological improvements. Subjects always received a less-preferred food in exchange for a token, whereas the competitor received either the same type of food for their token (equity) or a more favored food for it (inequity). Apes did not refuse more of the less-preferred food when a competitor had received the more favored food. Thus, with an improved methodology we failed to reproduce the findings of Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253-258, 2005] that apes show inequity aversion. PMID:19021260

  18. Testing taste sensitivity and aversion in very young children : development of a procedure

    NARCIS (Netherlands)

    Visser, J; Kroeze, J.H.A.; Kamps, WA; Bijleveld, CMA

    2000-01-01

    Taste perception in 45 3- to 6-year-old children was tested using procedures specifically designed for this age group. Detection thresholds for sucrose and urea were measured by a staircase method and aversion to urea was assessed hedonically, using drawings of facial expressions. All children under

  19. Opposing effects of appetitive and aversive cues on go/no-go behavior and motor excitability.

    Science.gov (United States)

    Chiu, Yu-Chin; Cools, Roshan; Aron, Adam R

    2014-08-01

    Everyday life, as well as psychiatric illness, is replete with examples where appetitive and aversive stimuli hijack the will, leading to maladaptive behavior. Yet the mechanisms underlying this phenomenon are not well understood. Here we investigate how motivational cues influence action tendencies in healthy individuals with a novel paradigm. Behaviorally, we observed that an appetitive cue biased go behavior (making a response), whereas an aversive cue biased no-go behavior (withholding a response). We hypothesized that the origin of this behavioral go/no-go bias occurs at the motor system level. To test this, we used single-pulse TMS as a motor system probe (rather than a disruptive tool) to index motivational biasing. We found that the appetitive cue biased the participants to go more by relatively increasing motor system excitability, and that the aversive cue biased participants to no-go more by relatively decreasing motor system excitability. These results show, first, that maladaptive behaviors arise from motivational cues quickly spilling over into the motor system and biasing behavior even before action selection and, second, that this occurs in opposing directions for appetitive and aversive cues. PMID:24564469

  20. Learning by Doing, Risk Aversion and Use of Risk Management Strategies

    OpenAIRE

    Uematsu, Hiroki; Ashok, Mishra K.

    2011-01-01

    Using a national survey, double hurdle models are estimated to examine the impact of farmers’ risk attitude on use of production and marketing contracts. Risk averse farmers are less likely to use contracts but risk attitude does not have any significant impact on the intensity at which contracts are adopted.

  1. Coordinated activity of ventral tegmental neurons adapts to appetitive and aversive learning.

    Science.gov (United States)

    Kim, Yunbok; Wood, Jesse; Moghaddam, Bita

    2012-01-01

    Our understanding of how value-related information is encoded in the ventral tegmental area (VTA) is based mainly on the responses of individual putative dopamine neurons. In contrast to cortical areas, the nature of coordinated interactions between groups of VTA neurons during motivated behavior is largely unknown. These interactions can strongly affect information processing, highlighting the importance of investigating network level activity. We recorded the activity of multiple single units and local field potentials (LFP) in the VTA during a task in which rats learned to associate novel stimuli with different outcomes. We found that coordinated activity of VTA units with either putative dopamine or GABA waveforms was influenced differently by rewarding versus aversive outcomes. Specifically, after learning, stimuli paired with a rewarding outcome increased the correlation in activity levels between unit pairs whereas stimuli paired with an aversive outcome decreased the correlation. Paired single unit responses also became more redundant after learning. These response patterns flexibly tracked the reversal of contingencies, suggesting that learning is associated with changing correlations and enhanced functional connectivity between VTA neurons. Analysis of LFP recorded simultaneously with unit activity showed an increase in the power of theta oscillations when stimuli predicted reward but not an aversive outcome. With learning, a higher proportion of putative GABA units were phase locked to the theta oscillations than putative dopamine units. These patterns also adapted when task contingencies were changed. Taken together, these data demonstrate that VTA neurons organize flexibly as functional networks to support appetitive and aversive learning. PMID:22238652

  2. Aversive Racism and Intergroup Contact Theories: Cultural Competence in a Segregated World

    Science.gov (United States)

    Rodenborg, Nancy A.; Boisen, Laura A.

    2013-01-01

    The United States remains highly segregated, and social work students are likely to live and work in segregated contexts. What implications does this have for their cultural competence? Does segregation affect social workers' ability to serve diverse clients without bias? This article reviews two social psychology theories, aversive racism…

  3. Discounting versus risk aversion: Their effects on individual demands for climate change mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, T.A. [Univ. of Oregon (United States). Dept. of Economics; Gerdes, G.R.

    2007-07-01

    Policies to reduce carbon emissions in an effort to prevent climate change involve large near-term costs and uncertain long-term benefits (i.e. the avoided future adverse consequences of climate change). This uncertainty, along with the very different time profiles of costs and benefits, means that risk aversion and time preferences will be key features of any model that seeks to explain heterogeneity in consumer demand for climate change mitigation programs. Unfortunately, while most reduced-form empirical demand models for climate change mitigation can easily control for individual characteristics such as age, gender, and income, these two key structural determinants -- risk preferences and time preferences -- are typically unobservable. Risk aversion and time preferences are important sources of heterogeneity in preferences for public policies with near-term costs and uncertain future benefits. Using stated preference data, the authors first jointly estimate individual-specific risk aversion and discount rate parameters then use these as individual 'characteristics' in a separate model to explain preferences for climate change mitigation policies. The more risk-averse the individual, and/or the lower their discount rate, the higher is their willingness to pay. The authors also simulate expected demand under counterfactual conditions -- such as risk neutrality, or the lower social discount rates that would be used by a benevolent central planner.

  4. Investigations on UCS-CS mediation in radiation-induced conditioned taste aversion

    International Nuclear Information System (INIS)

    Groups of 8 male Sprague-Dawley rats were used in an investigation of procaine and dimenhydrinate effects on radiation-induced taste aversion learning. Neither the local anesthetic procaine, administered intraperitoneally, nor the antinausea drug dimenhydrinate, administered intramuscularly, blocked acquisition of aversion to saccharin flavored water. Control animals confirmed that saccharin preferences appeared normally in non-irradiated animals, and that the drugs produced no aversion in the absence of radiation. Another investigation, using groups of 5 female Sprague-Dawley rats, showed a failure of dimenhydrinate in blocking the acquisition of a rotation-induced conditioned taste aversion. Two dose levels of the drug were used, 1 mg/kg and 2 mg/kg. At the dimenhydrinate dosage used in the study involving radiation (1.75 mg/kg) and at the higher dosage used in the study involving rotation, there appeared to be a potentiation of the effects of radiation and rotation, respectively. Results of these studies seem to favor a model for UCS-CS mediation as being diffuse and perhaps redundant. The possibility that nausea-producing stimuli may work synergistically was also discussed. (U.S.)

  5. Adolescent exposure to methylphenidate has no effect on the aversive properties of cocaine in adulthood.

    Science.gov (United States)

    Wetzell, Bradley; Riley, Anthony L

    2012-05-01

    Methylphenidate is the most widely prescribed pharmacotherapeutic treatment of AD/HD in children and teens and has actions that are also involved in drug reward and reinforcement. Its clinical use has often raised concerns over the possibility that it could potentiate the risk for later drug-related problems. Animals exposed to methylphenidate during adolescence exhibit attenuated cocaine-induced conditioned place preference, but tend to self-administer cocaine more quickly than controls. A drug's abuse potential, as reflected by self-administration, is thought to be the product of a balance between its rewarding and aversive properties, thus the present research assessed the effects of adolescent exposure to methylphenidate on conditioned taste aversions induced by cocaine in adulthood in 132 male Sprague Dawley rats. Although cocaine induced robust dose-dependent taste aversions in accordance with previous research, there were no effects of adolescent exposure to methylphenidate in spite of evidence that it was behaviorally active. The present results indicate that changes in adult cocaine self-administration are not likely mediated by changes in the aversive response. The possibility that such changes are a function of reductions in reward threshold is discussed. PMID:22342661

  6. Examining Relationships between Executive Functioning and Delay Aversion in Attention Deficit Hyperactivity Disorder

    Science.gov (United States)

    Karalunas, Sarah L.; Huang-Pollock, Cynthia L.

    2011-01-01

    Although motivation and cognition are often examined separately, recent theory suggests that a delay-averse motivational style may negatively impact development of executive functions (EFs), such as working memory (WM) and response inhibition (RI) for children with Attention Deficit Hyperactivity Disorder (ADHD; Sonuga-Barke, 2002). This model…

  7. Expression and pharmacological modulation of visceral pain-induced conditioned place aversion in mice.

    Science.gov (United States)

    Bagdas, Deniz; Muldoon, Pretal P; AlSharari, Shakir; Carroll, F Ivy; Negus, S Stevens; Damaj, M Imad

    2016-03-01

    Pain encompasses both a sensory as well as an affective dimension and these are differentially processed in the brain and periphery. It is therefore important to develop animal models to reflect the non-reflexive assays in pain. In this study, we compared effects of the mu opioid receptor agonist morphine, the nonsteroidal anti-inflammatory drug ketoprofen and the kappa receptor opioid agonist U50,488H and antagonist JDTic on acetic acid-induced stretching and acetic acid-induced aversion in the condition place aversion (CPA) test in male ICR mice. Intraperitoneal administration of acetic acid (0.32-1%) was equipotent in stimulating stretching and CPA. Ketoprofen, morphine and U50,488H all inhibited the acid-induced stretching. Ketoprofen and morphine also blocked the acid-induced CPA but U50,488H failed to do so. The reversal ability of ketoprofen and morphine on acid-induced CPA is unique to pain-stimulated place aversion since these drugs failed to reduce non-noxious LiCl-induced CPA. Overall, this study characterized and validated a preclinical mouse model of pain-related aversive behavior that can be used to assess genetic and biological mechanisms of pain as well as improving the predictive validity of preclinical studies on candidate analgesics. PMID:26639043

  8. Differential Endocannabinoid Regulation of Extinction in Appetitive and Aversive Barnes Maze Tasks

    Science.gov (United States)

    Harloe, John P.; Thorpe, Andrew J.; Lichtman, Aron H.

    2008-01-01

    CB[subscript 1] receptor-compromised animals show profound deficits in extinguishing learned behavior from aversive conditioning tasks, but display normal extinction learning in appetitive operant tasks. However, it is difficult to discern whether the differential involvement of the endogenous cannabinoid system on extinction results from the…

  9. Coordinated activity of ventral tegmental neurons adapts to appetitive and aversive learning.

    Directory of Open Access Journals (Sweden)

    Yunbok Kim

    Full Text Available Our understanding of how value-related information is encoded in the ventral tegmental area (VTA is based mainly on the responses of individual putative dopamine neurons. In contrast to cortical areas, the nature of coordinated interactions between groups of VTA neurons during motivated behavior is largely unknown. These interactions can strongly affect information processing, highlighting the importance of investigating network level activity. We recorded the activity of multiple single units and local field potentials (LFP in the VTA during a task in which rats learned to associate novel stimuli with different outcomes. We found that coordinated activity of VTA units with either putative dopamine or GABA waveforms was influenced differently by rewarding versus aversive outcomes. Specifically, after learning, stimuli paired with a rewarding outcome increased the correlation in activity levels between unit pairs whereas stimuli paired with an aversive outcome decreased the correlation. Paired single unit responses also became more redundant after learning. These response patterns flexibly tracked the reversal of contingencies, suggesting that learning is associated with changing correlations and enhanced functional connectivity between VTA neurons. Analysis of LFP recorded simultaneously with unit activity showed an increase in the power of theta oscillations when stimuli predicted reward but not an aversive outcome. With learning, a higher proportion of putative GABA units were phase locked to the theta oscillations than putative dopamine units. These patterns also adapted when task contingencies were changed. Taken together, these data demonstrate that VTA neurons organize flexibly as functional networks to support appetitive and aversive learning.

  10. A simultaneous approach to the estimation of risk aversion and the subjective time discount rate

    NARCIS (Netherlands)

    A.S. Booij; B.M.S. van Praag

    2009-01-01

    In this paper we analyze a sample of 1832 individuals who responded to six randomly generated lottery questions that differ with respect to chance, prize and the timing of the draw. Using a model that explicitly allows for consumption smoothing, we obtain an estimate of relative risk aversion of 82.

  11. Financial literacy, risk aversion and choice of mortgage type by households

    NARCIS (Netherlands)

    Cox, R.; Brounen, Dirk; Neuteboom, P.

    2015-01-01

    This paper analyzes how financial literacy and reported willingness to take financial risk impact a household’s choice of mortgage type. The results show that households reporting higher financial literacy and lower risk aversion are 55 to 97 % more likely to opt for interest-only mortgages. The res

  12. A Choice Procedure to Assess the Aversive Effects of Drugs in Rodents

    Science.gov (United States)

    Podlesnik, Christopher A.; Jimenez-Gomez, Corina; Woods, James H.

    2010-01-01

    The goal of this series of experiments was to develop an operant choice procedure to examine rapidly the punishing effects of intravenous drugs in rats. First, the cardiovascular effects of experimenter-administered intravenous histamine, a known aversive drug, were assessed to determine a biologically active dose range. Next, rats responded on…

  13. "A Lifelong Aversion to Writing": What if Writing Courses Emphasized Motivation?

    Science.gov (United States)

    Sullivan, Patrick

    2011-01-01

    There has been a great deal of groundbreaking research done on motivation during the last twenty-five years, and all of it points to the importance of intrinsic motivation. This research has very significant ramifications for teachers of English. In this essay, the author engages the issue of "aversion" that Linda Brodkey raises in her essay…

  14. Time of day-dependent latent inhibition of conditioned taste aversions in rats

    Czech Academy of Sciences Publication Activity Database

    Manrique, T.; Molero, A.; Ballesteros, M. A.; Morón, I.; Gallo, M.; Fenton, André Antonio

    2004-01-01

    Roč. 82, č. 2 (2004), s. 77-80. ISSN 1074-7427 Grant ostatní: CICYT(ES) BSO2002-01215 Institutional research plan: CEZ:AV0Z5011922 Keywords : condition taste aversion * latent inhibition * temporal context Subject RIV: FH - Neurology Impact factor: 4.443, year: 2004

  15. Gaze Aversion during Social Style Interactions in Autism Spectrum Disorder and Williams Syndrome

    Science.gov (United States)

    Doherty-Sneddon, Gwyneth; Whittle, Lisa; Riby, Deborah M.

    2013-01-01

    During face-to-face interactions typically developing individuals use gaze aversion (GA), away from their questioner, when thinking. GA is also used when individuals with autism (ASD) and Williams syndrome (WS) are thinking during question-answer interactions. We investigated GA strategies during face-to-face social style interactions with…

  16. A note on risk aversion and labour market outcomes: further evidence from German survey data

    OpenAIRE

    Pfeifer, Christian

    2008-01-01

    Using the large-scale German Socio-Economic Panel, this note reports direct empirical evidence for significant correlations between risk aversion and labour market outcomes (full-time employment, temporary agency work, fixed-term contracts, employer change, quits, training, wages, and job satisfaction).

  17. Optimal combined purchasing strategies for a risk-averse manufacturer under price uncertainty

    Directory of Open Access Journals (Sweden)

    Qiao Wu

    2015-09-01

    Full Text Available Purpose: The purpose of our paper is to analyze optimal purchasing strategies when a manufacturer can buy raw materials from a long-term contract supplier and a spot market under spot price uncertainty. Design/methodology/approach: This procurement model can be solved by using dynamic programming. First, we maximize the DM’s utility of the second period, obtaining the optimal contract quantity and spot quantity for the second period. Then, maximize the DM’s utility of both periods, obtaining the optimal purchasing strategy for the first period. We use a numerical method to compare the performance level of a pure spot sourcing strategy with that of a mixed strategy. Findings: Our results show that optimal purchasing strategies vary with the trend of contract prices. If the contract price falls, the total quantity purchased in period 1 will decrease in the degree of risk aversion. If the contract price increases, the total quantity purchased in period 1 will increase in the degree of risk aversion. The relationship between the optimal contract quantity and the degree of risk aversion depends on whether the expected spot price or the contract price is larger in period 2. Finally, we compare the performance levels between a combined strategy and a spot sourcing strategy. It shows that a combined strategy is optimal for a risk-averse buyer. Originality/value: It’s challenging to deal with a two-period procurement problem with risk consideration. We have obtained results of a two-period procurement problem with two sourcing options, namely contract procurement and spot purchases. Our model incorporates the buyer’s risk aversion factor and the change of contract prices, which are not addressed in early studies.

  18. Decomposing Self-Control: Individual Differences in Goal Pursuit Despite Interfering Aversion, Temptation, and Distraction

    Science.gov (United States)

    Steimke, Rosa; Stelzel, Christine; Gaschler, Robert; Rothkirch, Marcus; Ludwig, Vera U.; Paschke, Lena M.; Trempler, Ima; Kathmann, Norbert; Goschke, Thomas; Walter, Henrik

    2016-01-01

    Self-control can be defined as the ability to exert control over ones impulses. Currently, most research in the area relies on self-report. Focusing on attentional control processes involved in self-control, we modified a spatial selective attentional cueing task to test three domains of self-control experimentally in one task using aversive, tempting, and neutral picture-distractors. The aims of the study were (1) to investigate individual differences in the susceptibility to aversive, tempting, and neutral distraction within one paradigm and (2) to test the association of these three self-control domains to conventional measures of self-control including self-report. The final sample consisted of 116 participants. The task required participants to identify target letters “E” or “F” presented at a cued target location while the distractors were presented. Behavioral and eyetracking data were obtained during the performance of the task. High task performance was encouraged via monetary incentives. In addition to the attentional self-control task, self-reported self-control was assessed and participants performed a color Stroop task, an unsolvable anagram task and a delay of gratification task using chocolate sweets. We found that aversion, temptation, and neutral distraction were associated with significantly increased error rates, reaction times and gaze pattern deviations. Overall task performance on our task correlated with self-reported self-control ability. Measures of aversion, temptation, and distraction showed moderate split-half reliability, but did not correlate with each other across participants. Additionally, participants who made a self-controlled decision in the delay of gratification task were less distracted by temptations in our task than participants who made an impulsive choice. Our individual differences analyses suggest that (1) the ability to endure aversion, resist temptations and ignore neutral distractions are independent of each

  19. Medial amygdala lesions selectively block aversive Pavlovian-instrumental transfer in rats.

    Directory of Open Access Journals (Sweden)

    Joseph E. LeDoux

    2014-09-01

    Full Text Available Pavlovian conditioned stimuli (CSs play an important role in the reinforcement and motivation of instrumental active avoidance (AA. Conditioned threats can also invigorate ongoing AA responding (aversive Pavlovian-instrumental transfer or PIT. The neural circuits mediating AA are poorly understood, although lesion studies suggest that lateral, basal and central amygdala nuclei, as well as infralimbic prefrontal cortex, make key, and sometimes opposing, contributions. We recently completed an extensive analysis of brain c-Fos expression in good vs. poor avoiders following an AA test (Martinez et al 2013, Learning and Memory. This analysis identified medial amygdala (MeA as a potentially important region for Pavlovian motivation of instrumental actions. MeA is known to mediate defensive responding to innate threats as well as social behaviors, but its role in mediating aversive Pavlovian-instrumental interactions is unknown. We evaluated the effect of MeA lesions on Pavlovian conditioning, Sidman two-way AA conditioning (shuttling and aversive PIT in rats. Mild footshocks served as the unconditioned stimulus in all conditioning phases. MeA lesions had no effect on AA but blocked the expression of aversive PIT and 22 kHz ultrasonic vocalizations in the AA context. Interestingly, MeA lesions failed to affect Pavlovian freezing to discrete threats but reduced freezing to contextual threats when assessed outside of the AA chamber. These findings differentiate MeA from lateral and central amygdala, as lesions of these nuclei disrupt Pavlovian freezing and aversive PIT, but have opposite effects on AA performance. Taken together, these results suggest that MeA plays a selective role in the motivation of instrumental avoidance by general or uncertain Pavlovian threats.

  20. Decomposing Self-Control: Individual Differences in Goal Pursuit Despite Interfering Aversion, Temptation, and Distraction.

    Science.gov (United States)

    Steimke, Rosa; Stelzel, Christine; Gaschler, Robert; Rothkirch, Marcus; Ludwig, Vera U; Paschke, Lena M; Trempler, Ima; Kathmann, Norbert; Goschke, Thomas; Walter, Henrik

    2016-01-01

    Self-control can be defined as the ability to exert control over ones impulses. Currently, most research in the area relies on self-report. Focusing on attentional control processes involved in self-control, we modified a spatial selective attentional cueing task to test three domains of self-control experimentally in one task using aversive, tempting, and neutral picture-distractors. The aims of the study were (1) to investigate individual differences in the susceptibility to aversive, tempting, and neutral distraction within one paradigm and (2) to test the association of these three self-control domains to conventional measures of self-control including self-report. The final sample consisted of 116 participants. The task required participants to identify target letters "E" or "F" presented at a cued target location while the distractors were presented. Behavioral and eyetracking data were obtained during the performance of the task. High task performance was encouraged via monetary incentives. In addition to the attentional self-control task, self-reported self-control was assessed and participants performed a color Stroop task, an unsolvable anagram task and a delay of gratification task using chocolate sweets. We found that aversion, temptation, and neutral distraction were associated with significantly increased error rates, reaction times and gaze pattern deviations. Overall task performance on our task correlated with self-reported self-control ability. Measures of aversion, temptation, and distraction showed moderate split-half reliability, but did not correlate with each other across participants. Additionally, participants who made a self-controlled decision in the delay of gratification task were less distracted by temptations in our task than participants who made an impulsive choice. Our individual differences analyses suggest that (1) the ability to endure aversion, resist temptations and ignore neutral distractions are independent of each other and

  1. Dissociation of the Role of Infralimbic Cortex in Learning and Consolidation of Extinction of Recent and Remote Aversion Memory.

    Science.gov (United States)

    Awad, Walaa; Ferreira, Guillaume; Maroun, Mouna

    2015-10-01

    Medial prefrontal circuits have been reported to undergo a major reorganization over time and gradually take a more important role for remote emotional memories such as contextual fear memory or food aversion memory. The medial prefrontal cortex, and specifically its ventral subregion, the infralimbic cortex (IL), was also reported to be critical for recent memory extinction of contextual fear conditioning and conditioned odor aversion. However, its exact role in the extinction of remotely acquired information is still not clear. Using postretrieval blockade of protein synthesis or inactivation of the IL, we showed that the IL is similarly required for extinction consolidation of recent and remote fear memory. However, in odor aversion memory, the IL was only involved in extinction consolidation of recent, but not remote, memory. In contrast, only remote retrieval of aversion memory induced c-Fos activation in the IL and preretrieval inactivation of the IL with lidocaine impaired subsequent extinction of remote but not recent memory, indicating IL is necessary for extinction learning of remote aversion memory. In contrast to the effects in odor aversion, our data show that the involvement of the IL in the consolidation of fear extinction does not depend on the memory age. More importantly, our data indicate that the IL is implicated in the extinction of fear and nonfear-based associations and suggest dissociation in the engagement of the IL in the learning and consolidation of food aversion extinction over time. PMID:25872918

  2. Cognitive decline is associated with risk aversion and temporal discounting in older adults without dementia.

    Directory of Open Access Journals (Sweden)

    Bryan D James

    Full Text Available Risk aversion and temporal discounting are preferences that are strongly linked to sub-optimal financial and health decision making ability. Prior studies have shown they differ by age and cognitive ability, but it remains unclear whether differences are due to age-related cognitive decline or lower cognitive abilities over the life span. We tested the hypothesis that cognitive decline is associated with higher risk aversion and temporal discounting in 455 older persons without dementia from the Memory and Aging Project, a longitudinal cohort study of aging in Chicago. All underwent repeated annual cognitive evaluations using a detailed battery including 19 tests. Risk aversion was measured using standard behavioral economics questions: participants were asked to choose between a certain monetary payment versus a gamble in which they could gain more or nothing; potential gamble gains varied across questions. Temporal discounting: participants were asked to choose between an immediate, smaller payment and a delayed, larger one; two sets of questions addressed small and large stakes based on payment amount. Regression analyses were used to examine whether prior rate of cognitive decline predicted level of risk aversion and temporal discounting, controlling for age, sex, and education. Over an average of 5.5 (SD=2.9 years, cognition declined at an average of 0.016 units per year (SD=0.03. More rapid cognitive decline predicted higher levels of risk aversion (p=0.002 and temporal discounting (small stakes: p=0.01, high stakes: p=0.006. Further, associations between cognitive decline and risk aversion (p=0.015 and large stakes temporal discounting (p=0.026 persisted in analyses restricted to persons without any cognitive impairment (i.e., no dementia or mild cognitive impairment; the association of cognitive decline and small stakes temporal discounting was no longer statistically significant (p=0.078. These findings are consistent with the

  3. Induction of latent memory for conditioned food aversion and its transformation into "active" state depend on translation and transcription processes.

    Science.gov (United States)

    Solntseva, S V; Nikitin, V P

    2014-05-01

    Mechanisms of induction and retrieval of latent (hidden) memory for conditioned food aversion were investigated in snails. After initial training (single combination of a food stimulus with electric shock), aversive reactions to presentation of the conditioned food stimulus were not revealed. Repeated presentation of the stimuli in 12 days after the first combination was followed by the appearance of aversive food reactions that persisted for at least 14 days. Injections of inhibitors of protein (cycloheximide) or RNA (α-amanitin) synthesis immediately after the first or second combined presentation of the stimuli disturbed skill performance. We hypothesized that single combination of food and reinforcing stimuli led to translation- and transcription-dependent induction of latent conditioned food aversion memory. Transformation of this memory into an active state after repeated presentation of the stimulus combination also depends on the synthesis of new proteins and RNA. PMID:24906957

  4. Comparison of taste aversions induced by radiation and lithium chloride in CS--US and US--CS paradigms

    International Nuclear Information System (INIS)

    Conditioned taste aversions induced by ionizing radiation and LiCl were compared in both forward (CS--US, conditioned stimulus-unconditioned stimulus) and backward (US--CS) conditioning paradigms. Taste aversions were produced when a saccharin CS preceded or followed a 100-R radiation US by as much as 6 hr., but a 2 percent of body weight, .15 M LiCl US was effective only in CS--US pairings. It was argued that the ineffectiveness of a LiCl stimulus in US--CS pairings was not attributable to differences in the strength of the respective LiCl and radiation doses in that these doses yielded comparable aversions in forward pairings. These results were related to inadequacies of a sickness model of taste aversion conditioning. (U.S.)

  5. Quantifying uncertainty in pest risk maps and assessments : adopting a risk-averse decision maker’s perspective

    OpenAIRE

    Denys Yemshanov; Frank Koch; Mark Ducey; Robert Haack; Marty Siltanen; Kirsty Wilson

    2013-01-01

    Pest risk maps are important decision support tools when devising strategies to minimize introductions of invasive organisms and mitigate their impacts. When possible management responses to an invader include costly or socially sensitive activities, decision-makers tend to follow a more certain (i.e., risk-averse) course of action. We presented a new mapping technique that assesses pest invasion risk from the perspective of a risk-averse decision maker. We demonstrated the method by evaluati...

  6. Prefrontal/accumbal catecholamine system determines motivational salience attribution to both reward- and aversion-related stimuli

    OpenAIRE

    Ventura, Rossella; Morrone, Cristina; Puglisi-Allegra, Stefano

    2007-01-01

    Recent evidence suggests that rewarding and aversive stimuli affect the same brain areas, including medial prefrontal cortex and nucleus accumbens. Although nucleus accumbens is known to respond to salient stimuli, regardless of their hedonic valence, with selective increased dopamine release, little is known about the role of prefrontal cortex in reward- and aversion-related motivation or about the neurotransmitters involved. Here we find that selective norepinephrine depletion in medial pre...

  7. Hippocampal Erk mechanisms linking prediction error to fear extinction: Roles of shock expectancy and contextual aversive valence

    OpenAIRE

    Huh, Kyu Hwan; Guzman, Yomayra F.; Tronson, Natalie C.; Guedea, Anita L.; Gao, Can; Radulovic, Jelena

    2009-01-01

    Extinction of fear requires learning that anticipated aversive events no longer occur. Animal models reveal that sustained phosphorylation of the extracellular signal-regulated kinase (Erk) in hippocampal CA1 neurons plays an important role in this process. However, the key signals triggering and regulating the activity of Erk are not known. By varying the degree of expected and delivered aversive reinforcement, we demonstrate that Erk specifically responds to prediction errors of contextual ...

  8. Coordination of Supply Chain with One Supplier and Two Competing Risk-Averse Retailers under an Option Contract

    OpenAIRE

    Rui Wang; Shiji Song; Cheng Wu

    2016-01-01

    This paper studies an option contract for coordinating a supply chain comprising one risk-neutral supplier and two risk-averse retailers engaged in promotion competition in the selling season. For a given option contract, in decentralized case, each risk-averse retailer decides the optimal order quantity and the promotion policy by maximizing the conditional value-at-risk of profit. Based on the retailers’ decision, the supplier derives the optimal production policy by maximizing expected pro...

  9. Loss-Averse Inventory and Borrowing Decisions with Constraints on Working Capital in Fashion and Textiles Industry

    OpenAIRE

    Lijun Ma; Weili Xue; Yingxue Zhao; Xudong Lin

    2013-01-01

    Traditional inventory models focus on operational decisions and inventory control. Quite few models consider the financial constraint and decision bias such as loss aversion, which are the reality in today's business environment, especially for the fashion and textiles industry. In this paper we study the inventory control problem for a loss-averse retailer with financial constraint for operations in a periodic review setting in a finite horizon. We characterize the optimal inventory control ...

  10. Construction of a taste-blind medaka fish and quantitative assay of its preference–aversion behavior

    OpenAIRE

    Aihara, Y; Yasuoka, A; Iwamoto, S.; Yoshida, Y.; Misaka, T; Abe, K

    2008-01-01

    In vertebrates, the taste system provides information used in the regulation of food ingestion. In mammals, each cell group within the taste buds expresses either the T1R or the T2R taste receptor for preference–aversion discrimination. However, no such information is available regarding fish. We developed a novel system for quantitatively assaying taste preference–aversion in medaka fish. In this study, we prepared fluorescently labeled foods with fine cavities designed to retain tastants un...

  11. From Ambiguity Aversion to a Generalized Expected Utility. Modeling Preferences in a Quantum Probabilistic Framework

    CERN Document Server

    Aerts, Diederik

    2015-01-01

    Ambiguity and ambiguity aversion have been widely studied in decision theory and economics both at a theoretical and an experimental level. After Ellsberg's seminal studies challenging subjective expected utility theory (SEUT), several (mainly normative) approaches have been put forward to reproduce ambiguity aversion and Ellsberg-type preferences. However, Machina and other authors have pointed out some fundamental difficulties of these generalizations of SEUT to cope with some variants of Ellsberg's thought experiments, which has recently been experimentally confirmed. Starting from our quantum modeling approach to human cognition, we develop here a general probabilistic framework to model human decisions under uncertainty. We show that our quantum theoretical model faithfully represents different sets of data collected on both the Ellsberg and the Machina paradox situations, and is flexible enough to describe different subjective attitudes with respect to ambiguity. Our approach opens the way toward a quan...

  12. Deficient aversive-potentiated startle and the triarchic model of psychopathy: The role of boldness.

    Science.gov (United States)

    Esteller, Àngels; Poy, Rosario; Moltó, Javier

    2016-05-01

    This study examined the contribution of the phenotypic domains of boldness, meanness, and disinhibition of the triarchic conceptualization of psychopathy (Patrick, Fowles, & Krueger, 2009) to deficient aversive-potentiated startle in a mixed-gender sample of 180 undergraduates. Eyeblink responses to noise probes were recorded during a passive picture-viewing task (erotica, neutral, threat, and mutilation). Deficient threat vs. neutral potentiation was uniquely related to increased boldness scores, thus suggesting that the diminished defensive reaction to aversive stimulation is specifically linked to the charm, social potency and venturesomeness features of psychopathy (boldness), but not to features such as callousness, coldheartedness and cruelty traits (meanness), even though both phenotypes theoretically share the same underlying low-fear disposition. Our findings provide further evidence of the differential association between distinct psychopathy components and deficits in defensive reactivity and strongly support the validity of the triarchic model of psychopathy in disentangling the etiology of this personality disorder. PMID:27033014

  13. Induction of aversive learning through thermogenetic activation of Kenyon cell ensembles in Drosophila

    Directory of Open Access Journals (Sweden)

    David eVasmer

    2014-05-01

    Full Text Available Drosophila represents a model organism to analyze neuronal mechanisms underlying learning and memory. Kenyon cells of the Drosophila mushroom body are required for associative odor learning and memory retrieval. But is the mushroom body sufficient to acquire and retrieve an associative memory? To answer this question we have conceived an experimental approach to bypass olfactory sensory input and to thermogenetically activate sparse and random ensembles of Kenyon cells directly. We found that if the artifical activation of Kenyon cell ensembles coincides with a salient, aversive stimulus learning was induced The animals adjusted their behavior in a subsequent test situation and actively avoided reactivation of these Kenyon cells. Our results show that Kenyon cell activity in coincidence with a salient aversive stimulus can suffice to form an associative memory. Memory retrieval is characterized by a closed feedback loop between a behavioral action and the reactivation of sparse ensembles of Kenyon cells.

  14. Coordinating a Supply Chain with a Loss-Averse Retailer under Yield and Demand Uncertainties

    Directory of Open Access Journals (Sweden)

    Weiwei Luo

    2016-01-01

    Full Text Available This paper investigates the channel coordination of a supply chain (SC consisting of a loss-averse retailer and a risk-neutral supplier under yield and demand uncertainties. Three existing contracts are analyzed. Our results demonstrate that the buyback (BB and quantity flexibility (QF contracts can not only coordinate the supply chain but also lead to Pareto improvement for each player, while the wholesale price (WP contract fails to coordinate the chain due to the effects of double marginalization and risk preference. For comparison, a chain with a risk-neutral retailer is also analyzed. Furthermore, numerical examples are provided to demonstrate the effectiveness of the coordination contracts, and the impacts of loss aversion and random yield on the decision-making behaviors and system performance are then discussed.

  15. Financial Crisis from the Trust and Loss Aversion Perspective in Emerging Romanian Capital Market

    Directory of Open Access Journals (Sweden)

    Antoniade-Ciprian ALEXANDRU

    2011-07-01

    Full Text Available In this paper we synthesized a study of financial crisis from the trust and loss aversion perspective on a particular case, Romanian emerging capital market. In a relative recent study we stopped with our data series at the level of 2008, November, but in this paper we continue our research until 2009, December. In a world-wide financial crisis and a global financial depreciation of stocks the emergent markets are much more affected that the lack of money and investors aversion. We study, based on efficient market theory, the evolution of portfolio structure in balanced funds. We are interesting to make an evaluation of present sentiment of investing money in capital markets and especially in stocks. Also, is necessary to determine which are the most important problems in this situation and seek an adequate stimulus for future development of direct investment.

  16. Reappraising striatal D1- and D2-neurons in reward and aversion.

    Science.gov (United States)

    Soares-Cunha, Carina; Coimbra, Barbara; Sousa, Nuno; Rodrigues, Ana J

    2016-09-01

    The striatum has been involved in complex behaviors such as motor control, learning, decision-making, reward and aversion. The striatum is mainly composed of medium spiny neurons (MSNs), typically divided into those expressing dopamine receptor D1, forming the so-called direct pathway, and those expressing D2 receptor (indirect pathway). For decades it has been proposed that these two populations exhibit opposing control over motor output, and recently, the same dichotomy has been proposed for valenced behaviors. Whereas D1-MSNs mediate reinforcement and reward, D2-MSNs have been associated with punishment and aversion. In this review we will discuss pharmacological, genetic and optogenetic studies that indicate that there is still controversy to what concerns the role of striatal D1- and D2-MSNs in this type of behaviors, highlighting the need to reconsider the early view that they mediate solely opposing aspects of valenced behaviour. PMID:27235078

  17. Modeling OPEC behavior: theories of risk aversion for oil producer decisions

    International Nuclear Information System (INIS)

    Theories of OPEC such as price leadership, cartel, or game theoretic models suggest an incentive for OPEC members to expand their production capacity well above current levels in order to maximize revenues. Yet individual OPEC members consistently explore for and develop oil fields at a level well below their potential. The cause of low oil exploration and development efforts among OPEC members, and even some non-OPEC members, may have to do with risk aversion. This paper describes an alternative theory for OPEC behavior based on risk aversion using a two piece non-Neumann-Morgenstern utility function similar to Fishburn and Koehenberger (1979, Decision Science 10, 503-518), and Friedman and Savage (1948, Journal of political Economy 56). The model shows possible low oil production behavior. (author)

  18. Betrayal Aversion: Evidence from Brazil, China, Oman, Switzerland, Turkey, and the United States

    OpenAIRE

    Iris Bohnet; Fiona Greig; Benedikt Herrmann; Richard Zeckhauser

    2008-01-01

    Due to betrayal aversion, people take risks less willingly when the agent of uncertainty is another person rather than nature. Individuals in six countries (Brazil, China, Oman, Switzerland, Turkey, and the United States) confronted a binary-choice trust game or a risky decision offering the same payoffs and probabilities. Risk acceptance was calibrated by asking individuals their "minimum acceptable probability" (MAP) for securing the high payoff that would make them willing to accept the ri...

  19. Contract Strategies in Competing Supply Chains with Risk-Averse Suppliers

    OpenAIRE

    Baixun Li; Yongwu Zhou; Baozhuang Niu

    2013-01-01

    This paper investigates the equilibrium contract strategies of two competing supply chains. Each chain is composed of one risk-averse supplier and one risk-neutral retailer. The two suppliers, as Stackelberg leaders, can choose either wholesale price or revenue sharing contract. We compare the outcomes obtained from different scenarios and study the impact of competition density and risk attitudes on the suppliers’ contract choices. We find that it is always optimal for the first-moving suppl...

  20. Aversive Learning in Adolescents: Modulation by Amygdala–Prefrontal and Amygdala–Hippocampal Connectivity and Neuroticism

    OpenAIRE

    Garavan, Hugh

    2013-01-01

    PUBLISHED Neuroticism involves a tendency for enhanced emotional and cognitive processing of negative affective stimuli and a propensity to worry and be anxious. It is known that this trait modulates fear learning and the activation of brain regions involved in it such as the amygdala, hippocampus, and prefrontal cortex and their connectivity. Thirty-nine (21 female) 14-year-old healthy adolescents participated in functional magnetic resonance imaging (fMRI) of aversive pavlovian different...

  1. Measuring the Financial markets' perception of EMU enlargement:the role of ambiguity aversion

    OpenAIRE

    Cincibuch, Martin; Horníková, Martina

    2007-01-01

    Market views on EMU enlargement are measured by a new indicator based on the short-term dynamics of forward spreads. Conceptually, this indicator stems from the notion of ambiguity-averse agents in the sense of Knight. Specifically, we attempt to operationalize the incomplete preferences framework, which may allow for multiple equilibria supported by one set of fundamentals. This equilibrium indeterminacy may offer a way to reconcile short-term fluctuations of market prices with a relatively ...

  2. Behavioral architecture of opioid reward and aversion in C57BL/6 substrains

    OpenAIRE

    Kirkpatrick, Stacey L.; Bryant, Camron D.

    2015-01-01

    Drug liking vs. drug disliking is a subjective motivational measure in humans that assesses the addiction liability of drugs. Variation in this trait is hypothesized to influence vulnerability vs. resilience toward substance abuse disorders and likely contains a genetic component. In rodents and humans, conditioned place preference (CPP)/aversion (CPA) is a Pavlovian conditioning paradigm whereby a learned preference for the drug-paired environment is used to infer drug liking whereas a learn...

  3. Behavioral architecture of opioid reward and aversion in C57BL/6 substrains

    OpenAIRE

    Bryant, Camron D.

    2015-01-01

    Drug liking versus drug disliking is a subjective motivational measure in humans that assesses the addiction liability of drugs. Variation in this trait is hypothesized to influence vulnerability versus resilience toward substance abuse disorders and likely contains a genetic component. In rodents and humans, conditioned place preference (CPP) / aversion (CPA) is a Pavlovian conditioning paradigm whereby a learned preference for the drug-paired environment is used to infer drug liking whereas...

  4. The story of the moment: Risk averse Cypriot farmers respond to drought management

    OpenAIRE

    Thomas, Alban; Groom, Ben; Koundouri, Phoebe; Nauges, Celine

    2008-01-01

    Abstract This paper illustrates the importance of estimating risk preferences when evaluating water policy. Using agricultural production data from the Kiti region of Cyprus we estimate farmers? risk preferences a la Antle (1983, 1987) and show sensitivity to higher order moments of profit, such as skewness. We show that farmers in the Kiti region are risk averse with risk premiums in the region of 20% of expected profit. We use these estimates to analyse the impact of a water quot...

  5. Three essays on gender issues in accounting, governance and risk aversion

    OpenAIRE

    Scapin, Mariano Pablo

    2015-01-01

    This Thesis presents three studies on gender issues in accounting, governance and risk aversion. Chapter one analyzes the effects of the introduction of gender quotas on boards of directors on the monitoring role of boards. Chapter two studies whether males and females have different preferences over risk than their male counterparts in the particular setting of a multiple choice exam. Finally, chapter three studies the determinants—at firm level—of hiring female board members ...

  6. Loss Aversion in Sequential Auctions: Endogenous Interdependence, Informational Externalities and the "Afternoon Effect"

    OpenAIRE

    Rosato, Antonio

    2014-01-01

    Empirical evidence from sequential auctions shows that prices of identical goods tend to decline between rounds. In this paper, I show how expectations-based reference-dependent preferences and loss aversion can rationalize this phenomenon. I analyze two-round sealed-bid auctions with symmetric bidders having independent private values and unit demand. Equilibrium bids in the second round are history-dependent and subject to a "discouragement effect": the higher the winning bid in the first a...

  7. Diversification in Private Equity Funds: On Knowledge-sharing, Risk-aversion and Limited-attention

    OpenAIRE

    Humphery-Jenner, M.

    2011-01-01

    This paper examines diversification as a source of value creation and destruction in private equity. The literature has focused on the `diversification discount' in corporations. It has not analyzed diversification in PE-funds, where diversification might increase value by ameliorating managerial risk aversion and by facilitating knowledge sharing. Thus, I examine a sample of 1505 PE-funds to show that industry and geographic diversification increases PE-fund returns on average, this is likel...

  8. Diversification in Private Equity Funds : On Knowledge-sharing, Risk-aversion and Limited-attention

    OpenAIRE

    2011-01-01

    This paper examines diversification as a source of value creation and destruction in private equity. The literature has focused on the `diversification discount' in corporations. It has not analyzed diversification in PE-funds, where diversification might increase value by ameliorating managerial risk aversion and by facilitating knowledge sharing. Thus, I examine a sample of 1505 PE-funds to show that industry and geographic diversification increases PE-fund returns on average, this is likel...

  9. Who cooperates in repeated games: The role of altruism, inequity aversion, and demographics

    OpenAIRE

    Dreber-Almenberg, Anna; Fudenberg, Drew; Rand, David G.

    2014-01-01

    We explore the extent to which altruism, as measured by giving in a dictator game (DG), accounts for play in a noisy version of the repeated prisoner's dilemma. We find that DG giving is correlated with cooperation in the repeated game when no cooperative equilibria exist, but not when cooperation is an equilibrium. Furthermore, none of the commonly observed strategies are better explained by inequity aversion or efficiency concerns than money maximization. Various survey questions provide ad...

  10. The significance of learned food aversions in the aetiology of anorexia associated with cancer.

    OpenAIRE

    Levine, J A; Emery, P W

    1987-01-01

    The results of 24 h food preference tests have suggested that learned food aversions may be involved in the development of anorexia in tumour bearing rats and in patients with cancer. We have performed similar tests over longer periods, up to 10 days, in male rats implanted with Leydig cell tumours, using semisynthetic diets containing differing proportions of fat, protein and carbohydrate. Tumour growth caused anorexia (16-30% decrease in food intake) and cachexia (78% decrease in body fat a...

  11. Rapid taste-aversion learning by an isolated molluscan central nervous system.

    OpenAIRE

    Chang, J. J.; Gelperin, A

    1980-01-01

    The isolated lips and nervous system of the terrestrial slug Limax maximus will produce some of the feeding behavior of the intact animal; i.e., they generate the rhythmic neural activity characteristic of ingestion in response to food extracts applied to the lips. This preparation will respond to a variety of food extracts that elicit feeding in the whole animal. This provides the opportunity for aversive conditioning experiments involving taste discrimination. Pairing lip chemostimulation b...

  12. Loss Modification Incentives for Insurers Under Expected Utility and Loss Aversion

    OpenAIRE

    Soetevent, Adriaan; Zhou, L.

    2014-01-01

    Forthcoming in 'De Economist'. Given the possibility to modify the probability of a loss, will a profit-maximizing insurer engage in loss prevention or is it in his interest to increase the loss probability? This paper investigates this question. First, we calculate the expected profit maximizing loss probability within an expected utility framework. We then use Köszegi and Rabin's (2006, 2007) loss aversion model to answer the same question for the case where consumers have reference-depende...

  13. Target-driven investing: Optimal investment strategies in defined contribution pension plans under loss aversion

    OpenAIRE

    Blake, David; Wright, Douglas; Zhang, Yumeng

    2011-01-01

    Assuming the loss aversion framework of Tversky and Kahneman (1992), stochastic investment and labour income processes, and a path-dependent fund target, we show that the optimal investment strategy for defined contribution pension plan members is a target-driven 'threshold' strategy, whereby the equity allocation is increased if the accumulating fund is below target and is decreased if it is above. However, if the fund is sufficiently above target, the optimal investment strategy switches to...

  14. How do working-memory-related demand, reasoning ability and aversive reinforcement modulate conflict monitoring?

    OpenAIRE

    Leue, Anja; Weber, Bernd; Beauducel, André

    2014-01-01

    Conflict monitoring is a process of stimulus evaluation and a pre-requisite for subsequent recruitment of cognitive control and behavioral adaptations. This study investigated how experimentally manipulated working-memory-related cognitive demand and aversive reinforcement modulate individual differences of conflict monitoring intensity and behavioral adjustments. Individual differences were assessed by means of an anxiety-related trait dimension (trait-BIS) and by means of reasoning abilitie...

  15. Bid and Ask Prices Tailored to Traders' Risk Aversion and Gain Propension: a Normative Approach

    Directory of Open Access Journals (Sweden)

    Marta Cardin

    2012-12-01

    Full Text Available Risky asset bid and ask prices “tailored” to the risk-aversion and the gain-propension of the traders are set up. They are calculated through the principle of the Extended Gini premium, a standard method used in non-life insurance. Explicit formulae for the most common stochastic distributions of risky returns, are calculated. Sufficient and necessary conditions for successful trading are also discussed.

  16. Covered Purchasing Power Parity, Ex-Ante PPP and Risk Aversion

    OpenAIRE

    Moore, Michael J.

    1992-01-01

    The standard expectations augmented theory of ex-ante purchasing power parity (PPP), which was first developed by Roll, assumes that agents are risk neutral. A Covered Purchasing Power Condition is developed which holds for the general case of risk aversion. A risk-augmented form of ex-ante PPP is then derived using a Lucas-style asset pricing framework. From this I conclude that real exchange rates may not possess the martingale property though the analysis clarifies the circumstances under ...

  17. Reacquisition, reinstatement, and renewal of a conditioned taste aversion in preweanling rats.

    Science.gov (United States)

    Revillo, D A; Castello, S; Paglini, G; Arias, C

    2014-05-01

    Pavlovian extinction is defined as a reduction of the conditioned response (CR) as a consequence of repeated and nonreinforced presentations of the conditioned stimulus (CS). This phenomenon has been explained through two nonexclusive associative hypotheses. One of them proposes that the CS-unconditioned stimulus (US) association is weakened during extinction, while the second one explains extinction by the formation of a new inhibitory association between the CS, and the US (CS-noUS) which competes with the excitatory one acquired at conditioning (CS-US). Research supporting this second hypothesis is based on the demonstration that the CR can be recovered after extinction. However, in preweanling rats, renewal, and reinstatement treatments have failed to recover a conditioned fear response, suggesting that extinction during this ontogenetic period may involve erasure of the CS-US association. The goal of the present study was to explore whether this conclusion can be extended to the extinction of a conditioned taste aversion by evaluating infant rats in three different procedures (reacquisition, ABA renewal, and reinstatement). The results are consistent with the idea that extinction of a taste aversive memory during infancy involves relearning about the relationship between the CS and the US, with the initial CS-US association remaining relatively intact. Extinction of a taste aversive memory and a fear memory may involve different biological mechanisms during infancy. The conclusion that the only psychological mechanism for extinction during infancy is unlearning should be confined to a particular type of memory. PMID:23765264

  18. Aversive Learning and Appetitive Motivation Toggle Feed-Forward Inhibition in the Drosophila Mushroom Body.

    Science.gov (United States)

    Perisse, Emmanuel; Owald, David; Barnstedt, Oliver; Talbot, Clifford B; Huetteroth, Wolf; Waddell, Scott

    2016-06-01

    In Drosophila, negatively reinforcing dopaminergic neurons also provide the inhibitory control of satiety over appetitive memory expression. Here we show that aversive learning causes a persistent depression of the conditioned odor drive to two downstream feed-forward inhibitory GABAergic interneurons of the mushroom body, called MVP2, or mushroom body output neuron (MBON)-γ1pedc>α/β. However, MVP2 neuron output is only essential for expression of short-term aversive memory. Stimulating MVP2 neurons preferentially inhibits the odor-evoked activity of avoidance-directing MBONs and odor-driven avoidance behavior, whereas their inhibition enhances odor avoidance. In contrast, odor-evoked activity of MVP2 neurons is elevated in hungry flies, and their feed-forward inhibition is required for expression of appetitive memory at all times. Moreover, imposing MVP2 activity promotes inappropriate appetitive memory expression in food-satiated flies. Aversive learning and appetitive motivation therefore toggle alternate modes of a common feed-forward inhibitory MVP2 pathway to promote conditioned odor avoidance or approach. PMID:27210550

  19. Egr-1 induction provides a genetic response to food aversion in zebrafish

    Directory of Open Access Journals (Sweden)

    Brigitte eBoyer

    2013-05-01

    Full Text Available As soon as zebrafish larvae start eating, they exhibit a marked aversion for bitter and acidic substances, as revealed by a consumption assay, in which fluorescent Tetrahymena serve as a feeding basis, to which various stimuli can be added. Bitter and acidic substances elicited an increase in mRNA accumulation of the immediate-early response gene egr-1, as revealed by in situ hybridization. Conversely, chemostimulants that did not induce aversion did not induce egr-1 response. Maximum labelling was observed in cells located in the oropharyngeal cavity and on the gill rakers. Gustatory areas of the brain were also labelled. Interestingly, when bitter tastants were repeatedly associated with food reward, zebrafish juveniles learned to ingest food in the presence of the bitter compound. After habituation, the acquisition of acceptance for bitterness was accompanied by a loss of egr-1 labelling. Altogether, our data indicate that egr-1 participates specifically in food aversion. The existence of reward-coupled changes in taste sensitivity in humans suggests that our results are relevant to situations in humans.

  20. Reward salience and risk aversion underlie differential ACC activity in substance dependence

    Directory of Open Access Journals (Sweden)

    William H. Alexander

    2015-01-01

    Full Text Available The medial prefrontal cortex, especially the dorsal anterior cingulate cortex (ACC, has long been implicated in cognitive control and error processing. Although the association between ACC and behavior has been established, it is less clear how ACC contributes to dysfunctional behavior such as substance dependence. Evidence from neuroimaging studies investigating ACC function in substance users is mixed, with some studies showing disengagement of ACC in substance dependent individuals (SDs, while others show increased ACC activity related to substance use. In this study, we investigate ACC function in SDs and healthy individuals performing a change signal task for monetary rewards. Using a priori predictions derived from a recent computational model of ACC, we find that ACC activity differs between SDs and controls in factors related to reward salience and risk aversion between SDs and healthy individuals. Quantitative fits of a computational model to fMRI data reveal significant differences in best fit parameters for reward salience and risk preferences. Specifically, the ACC in SDs shows greater risk aversion, defined as concavity in the utility function, and greater attention to rewards relative to reward omission. Furthermore, across participants risk aversion and reward salience are positively correlated. The results clarify the role that ACC plays in both the reduced sensitivity to omitted rewards and greater reward valuation in SDs. Clinical implications of applying computational modeling in psychiatry are also discussed.

  1. Impact of Investor's Varying Risk Aversion on the Dynamics of Asset Price Fluctuations

    CERN Document Server

    Yuan, B; Yuan, Baosheng; Chen, Kan

    2005-01-01

    While the investors' responses to price changes and their price forecasts are well accepted major factors contributing to large price fluctuations in financial markets, our study shows that investors' heterogeneous and dynamic risk aversion (DRA) preferences may play a more critical role in the dynamics of asset price fluctuations. We propose and study a model of an artificial stock market consisting of heterogeneous agents with DRA, and we find that DRA is the main driving force for excess price fluctuations and the associated volatility clustering. We employ a popular power utility function, $U(c,\\gamma)=\\frac{c^{1-\\gamma}-1}{1-\\gamma}$ with agent specific and time-dependent risk aversion index, $\\gamma_i(t)$, and we derive an approximate formula for the demand function and aggregate price setting equation. The dynamics of each agent's risk aversion index, $\\gamma_i(t)$ (i=1,2,...,N), is modeled by a bounded random walk with a constant variance $\\delta^2$. We show numerically that our model reproduces most ...

  2. Dopamine Regulates Aversive Contextual Learning and Associated In Vivo Synaptic Plasticity in the Hippocampus

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    John I. Broussard

    2016-03-01

    Full Text Available Dopamine release during reward-driven behaviors influences synaptic plasticity. However, dopamine innervation and release in the hippocampus and its role during aversive behaviors are controversial. Here, we show that in vivo hippocampal synaptic plasticity in the CA3-CA1 circuit underlies contextual learning during inhibitory avoidance (IA training. Immunohistochemistry and molecular techniques verified sparse dopaminergic innervation of the hippocampus from the midbrain. The long-term synaptic potentiation (LTP underlying the learning of IA was assessed with a D1-like dopamine receptor agonist or antagonist in ex vivo hippocampal slices and in vivo in freely moving mice. Inhibition of D1-like dopamine receptors impaired memory of the IA task and prevented the training-induced enhancement of both ex vivo and in vivo LTP induction. The results indicate that dopamine-receptor signaling during an aversive contextual task regulates aversive memory retention and regulates associated synaptic mechanisms in the hippocampus that likely underlie learning.

  3. Conditions Facilitating the Aversion of Unpopular Norms: An Agent-Based Simulation Study

    Directory of Open Access Journals (Sweden)

    Zoofishan Zareen

    2016-07-01

    Full Text Available People mostly facilitate and manage their social lives adhering to the prevalent norms. There are some norms which are unpopular, yet people adhere to them. Ironically, people at individual level do not agree to these norms, but, they still follow and even facilitate them. Irrespective of the social and psychological reasons behind their persistence, sometimes, for societal good, it is necessary to oppose and possibly avert the unpopular norms. In this paper, we model theorydriven computational specifications of Emperor’s Dilemma into an agent-based simulation, to understand the the conditions that result in emergence of unpopular norms. The reciprocal nature of persistence and aversion of norms, thus, is utilized to define situations under which these norms can be changed and averted. Simulation is performed under many interesting “what-if” questions. The simulation results reveal that under high density conditions of agent population with a high percentage of norm aversion activists, the aversion of unpopular norms can be achieved.

  4. Dissecting a role for melanopsin in behavioural light aversion reveals a response independent of conventional photoreception.

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    Ma'ayan Semo

    Full Text Available Melanopsin photoreception plays a vital role in irradiance detection for non-image forming responses to light. However, little is known about the involvement of melanopsin in emotional processing of luminance. When confronted with a gradient in light, organisms exhibit spatial movements relative to this stimulus. In rodents, behavioural light aversion (BLA is a well-documented but poorly understood phenomenon during which animals attribute salience to light and remove themselves from it. Here, using genetically modified mice and an open field behavioural paradigm, we investigate the role of melanopsin in BLA. While wildtype (WT, melanopsin knockout (Opn4(-/- and rd/rd cl (melanopsin only (MO mice all exhibit BLA, our novel methodology reveals that isolated melanopsin photoreception produces a slow, potentiating response to light. In order to control for the involvement of pupillary constriction in BLA we eliminated this variable with topical atropine application. This manipulation enhanced BLA in WT and MO mice, but most remarkably, revealed light aversion in triple knockout (TKO mice, lacking three elements deemed essential for conventional photoreception (Opn4(-/- Gnat1(-/- Cnga3(-/-. Using a number of complementary strategies, we determined this response to be generated at the level of the retina. Our findings have significant implications for the understanding of how melanopsin signalling may modulate aversive responses to light in mice and humans. In addition, we also reveal a clear potential for light perception in TKO mice.

  5. Time-dependent effects of treadmill exercise on aversive memory and cyclooxygenase pathway function.

    Science.gov (United States)

    Lovatel, Gisele Agustini; Bertoldi, Karine; Elsner, Viviane Rostirola; Vanzella, Cláudia; Moysés, Felipe Dos Santos; Spindler, Christiano; Funck, Vinicius Rafael; Pereira, Leticia Meier; de Oliveira, Clarissa Vasconcelos; Oliveira, Mauro Schneider; Netto, Carlos Alexandre; Siqueira, Ionara Rodrigues

    2012-09-01

    Exercise induces brain function adaptations and improves learning and memory; however the time window of exercise effects has been poorly investigated. Studies demonstrate an important role for cyclooxygenase-2 (COX-2) pathway function in the mechanisms underlying memory formation. The aim of present work was to investigate the effects of treadmill exercise on aversive memory and COX-2, PGE(2) and E-prostanoid receptors contents in the rat hippocampus at different time points after exercise has ended. Adult male Wistar rats were assigned to non-exercised (sedentary) and exercised (running daily for 20min, for 2weeks) groups. The inhibitory avoidance task was used to assess aversive memory and the COX-2, PGE(2) and E-prostanoid receptors (EP1, EP2, EP3 and EP4) levels were determined 1h, 18h, 3days or 7days after the last training session of treadmill exercise. The step down latency in the inhibitory avoidance, COX-2 and EP4 receptors levels were acutely increased by exercise, with a significant positive correlation between aversive memory performance and COX-2 levels. Increased EP2 content decreased PGE(2) levels were observed 7days after the last running session. The treadmill exercise protocol facilitates inhibitory avoidance memory and induces time-dependent changes on COX-2 pathways function (COX-2, PGE(2) and EP receptors). PMID:22728946

  6. Effects of aversive stimuli on prospective memory. An event-related fMRI study.

    Directory of Open Access Journals (Sweden)

    Massimiliano Rea

    Full Text Available Prospective memory (PM describes the ability to execute a previously planned action at the appropriate point in time. Although behavioral studies clearly showed that prospective memory performance is affected by the emotional significance attributed to the intended action, no study so far investigated the brain mechanisms subserving the modulatory effect of emotional salience on PM performance. The general aim of the present study was to explore brain regions involved in prospective memory processes when PM cues are associated with emotional stimuli. In particular, based on the hypothesised critical role of the prefrontal cortex in prospective memory in the presence of emotionally salient stimuli, we expected a stronger involvement of aPFC when the retrieval and execution of the intended action is cued by an aversive stimulus. To this aim BOLD responses of PM trials cued by aversive facial expressions were compared to PM trials cued by neutral facial expressions. Whole brain analysis showed that PM task cued by aversive stimuli is differentially associated with activity in the right lateral prefrontal area (BA 10 and in the left caudate nucleus. Moreover a temporal shift between the response of the caudate nucleus that preceded that of aPFC was observed. These findings suggest that the caudate nucleus might provide an early analysis of the affective properties of the stimuli, whereas the anterior lateral prefrontal cortex (BA10 would be involved in a slower and more deliberative analysis to guide goal-directed behaviour.

  7. Risk aversion and willingness to pay for energy efficient systems in rental apartments

    Energy Technology Data Exchange (ETDEWEB)

    Farsi, Mehdi [Centre for Energy Policy and Economics, ETH Zurich, Zuerichbergstr. 18, Zurich 8032 (Switzerland)

    2010-06-15

    This paper uses a random utility model to estimate consumers' valuation of energy efficient insulation and ventilation systems in rental apartments. Given consumers' limited experience in residential buildings and the perceived uncertainty about their comfort benefits and resulting energy savings, these relatively new technologies might be undervalued by risk-averse consumers. Using the concept of certainty-equivalence, this paper proposes a model to assess the consumers' risk-aversion for adopting energy-efficient systems. These systems are treated as risky assets while conventional commodities are assumed to be risk-free. The curvature of the utility function is interpreted as a measure of aversion to perceived risks as opposed to explicit risks measured by observed variances. The proposed formulation is applicable in stated preference data with qualitative variables. The model is applied to data from a choice experiment conducted among 264 apartment tenants in Switzerland. The estimated curvatures reject the risk-neutrality hypothesis. The range of the estimated risk premiums suggests that risk considerations remain a central issue in dealing with energy efficiency in residential buildings. The analysis also indicates that assuming same risk attitudes toward new and conventional systems could bias the estimates of the willingness to pay, especially when the system is comprised of several components. (author)

  8. Coordinating a Supply Chain with a Loss-Averse Retailer and Effort Dependent Demand

    Science.gov (United States)

    Li, Liying

    2014-01-01

    This study investigates the channel coordination issue of a supply chain with a risk-neutral manufacturer and a loss-averse retailer facing stochastic demand that is sensitive to sales effort. Under the loss-averse newsvendor setting, a distribution-free gain/loss-sharing-and-buyback (GLB) contract has been shown to be able to coordinate the supply chain. However, we find that a GLB contract remains ineffective in managing the supply chain when retailer sales efforts influence the demand. To effectively coordinate the channel, we propose to combine a GLB contract with sales rebate and penalty (SRP) contract. In addition, we discover a special class of gain/loss contracts that can coordinate the supply chain and arbitrarily allocate the expected supply chain profit between the manufacturer and the retailer. We then analyze the effect of loss aversion on the retailer's decision-making behavior and supply chain performance. Finally, we perform a numerical study to illustrate the findings and gain additional insights. PMID:25197696

  9. The involvement of nucleus accumbens dopamine in appetitive and aversive motivation.

    Science.gov (United States)

    Salamone, J D

    1994-04-18

    In recent years, considerable emphasis has been placed upon the putative role of nucleus accumbens dopamine systems in appetitive motivation and positive reinforcement. However, considerable evidence indicates that brain dopamine in general, and nucleus accumbens dopamine in particular, is involved in aspects of aversive motivation. Administration of dopamine antagonists or localized interference with nucleus accumbens dopamine systems has been shown to disrupt active avoidance behavior. In addition, accumbens dopamine release and metabolism is activated by a wide variety of stressful conditions. A review of the literature indicates that there are substantial similarities between the characteristics of dopaminergic involvement in appetitive and aversive motivation. There is conflicting evidence about the role of dopamine in emotion, and little evidence to suggest that the profound and consistent changes in instrumental behavior produced by interference with DA systems are due to direct dopaminergic mediation of positive affective responses such as hedonia. It is suggested that nucleus accumbens dopamine is involved in aspects of sensorimotor functions that are involved in both appetitive and aversive motivation. PMID:8037860

  10. Optimal Pricing Strategies and Computer Simulation of DCSC with Fairness Preference and Risk-Aversion Members

    Directory of Open Access Journals (Sweden)

    Guangxing Wei

    2013-07-01

    Full Text Available Firstly, this paper develop a basic two-echelon DCSC model as the comparative benchmark in the general case of the stochastic demand effected by the service level of the retailer, where the manufacturer's optimal direct price, wholesale price and the retailer's optimal retail price were achieved under Stackelberg game. Then, through incorporate the fairness preference and risk-aversion characteristics into the basic DCSC model, the manufacturer's optimal direct price, wholesale price and the retailer's optimal retail price were obtained under Stackelberg game. At last, by the numerical simulation, the effect of fairness preference and risk aversion level on the optimal pricing strategies and utility of DCSC was examined respectively. The results show that for a DCSC with fairness preference and risk aversion members, the manufacturer and the retailer will choose a reduced price to avoid income risk even if the market demand is stable. Although the decision makers can realize the improvement of their own utility in some circumstances, the utility of the whole supply chain always presents decreasing.    

  11. Brain-derived neurotrophic factor into adult neocortex strengthens a taste aversion memory.

    Science.gov (United States)

    Martínez-Moreno, Araceli; Rodríguez-Durán, Luis F; Escobar, Martha L

    2016-01-15

    Nowadays, it is known that brain derived neurotrophic-factor (BDNF) is a protein critically involved in regulating long-term memory related mechanisms. Previous studies from our group in the insular cortex (IC), a brain structure of the temporal lobe implicated in acquisition, consolidation and retention of conditioned taste aversion (CTA), demonstrated that BDNF is essential for CTA consolidation. Recent studies show that BDNF-TrkB signaling is able to mediate the enhancement of memory. However, whether BDNF into neocortex is able to enhance aversive memories remains unexplored. In the present work, we administrated BDNF in a concentration capable of inducing in vivo neocortical LTP, into the IC immediately after CTA acquisition in two different conditions: a "strong-CTA" induced by 0.2M lithium chloride i.p. as unconditioned stimulus, and a "weak-CTA" induced by 0.1M lithium chloride i.p. Our results show that infusion of BDNF into the IC converts a weak CTA into a strong one, in a TrkB receptor-dependent manner. The present data suggest that BDNF into the adult insular cortex is sufficient to increase an aversive memory-trace. PMID:26433146

  12. Rats taste-aversive learning with cyclosporine a is not affected by contextual changes.

    Science.gov (United States)

    Tuerkmen, Akin; Bösche, Katharina; Lückemann, Laura; Engler, Harald; Schedlowski, Manfred; Hadamitzky, Martin

    2016-10-01

    In conditioned taste aversion (CTA) rats associate a novel taste (conditioned stimulus; CS) with a treatment (unconditioned stimulus; US) that induces symptoms of malaise. During retrieval, animals learn that the CS no longer predicts the US, with the consequence that the behavior elicited by the CS extinguishes. Importantly, CTA data with lithium chloride (LiCl) as US indicate that extinction learning is affected by changing the physical context. However, if this is also the case in different taste-aversion paradigms employing compounds other than LiCL as US is unknown. Against this background the present study investigated in a CTA paradigm with saccharin as CS and the immunosuppressant cyclosporine A (CsA) as US the influence of contextual changes on CTA extinction. Our results show, that extinction of a learned CS-US association with CsA is not prone to contextual changes. Due to the direct effects of CsA on CNS functioning, CTA with this immunosuppressant apparently operates under different mechanisms compared to other drugs, such as LiCl. These data indicate that taste aversive learning and its extinction are not necessarily specific to the context in which it is learned but also depends, at least in part, on the physiological and neuropharmacological effects of the drug employed as US. PMID:27316343

  13. Risk aversion and willingness to pay for energy efficient systems in rental apartments

    International Nuclear Information System (INIS)

    This paper uses a random utility model to estimate consumers' valuation of energy efficient insulation and ventilation systems in rental apartments. Given consumers' limited experience in residential buildings and the perceived uncertainty about their comfort benefits and resulting energy savings, these relatively new technologies might be undervalued by risk-averse consumers. Using the concept of certainty-equivalence, this paper proposes a model to assess the consumers' risk-aversion for adopting energy-efficient systems. These systems are treated as risky assets while conventional commodities are assumed to be risk-free. The curvature of the utility function is interpreted as a measure of aversion to perceived risks as opposed to explicit risks measured by observed variances. The proposed formulation is applicable in stated preference data with qualitative variables. The model is applied to data from a choice experiment conducted among 264 apartment tenants in Switzerland. The estimated curvatures reject the risk-neutrality hypothesis. The range of the estimated risk premiums suggests that risk considerations remain a central issue in dealing with energy efficiency in residential buildings. The analysis also indicates that assuming same risk attitudes toward new and conventional systems could bias the estimates of the willingness to pay, especially when the system is comprised of several components.

  14. Neural mechanisms of the nucleus accumbens circuit in reward and aversive learning.

    Science.gov (United States)

    Hikida, Takatoshi; Morita, Makiko; Macpherson, Tom

    2016-07-01

    The basal ganglia are key neural substrates not only for motor function, but also cognitive functions including reward and aversive learning. Critical for these processes are the functional role played by two projection neurons within nucleus accumbens (NAc); the D1- and D2-expressing neurons. Recently, we have developed a novel reversible neurotransmission blocking technique that specifically blocks neurotransmission from NAc D1- and D2-expressing neurons, allowing for in vivo analysis. In this review, we outline the functional dissociation of NAc D1- and D2-expressing neurons of the basal ganglia in reward and aversive learning, as well as drug addiction. These studies have revealed the importance of activation of NAc D1 receptors for reward learning and drug addiction, and inactivation of NAc D2 receptors for aversive learning and flexibility. Based on these findings, we propose a neural mechanism, in which dopamine neurons in the ventral tegmental area that send inputs to the NAc work as a switch between D1- and D2-expressing neurons. These basal ganglia neural mechanisms will give us new insights into the pathophysiology of neuropsychiatric diseases. PMID:26827817

  15. Dexamethasone: a potent blocker for radiation-induced taste aversion in rats

    International Nuclear Information System (INIS)

    Rats, trained to drink water during a single 30-min period each day, were then given 0.1% saccharin twice a week and water on other days for 30 min. If 20 rad of radiation (0.2 Gy) were given each time 30 to 40 min after the saccharin the rats developed a profound aversion to saccharin during the course of three weeks, whereas control groups failed to do so. This paradigm was then used to test the ability of drugs, given twice weekly immediately after the saccharin, to prevent the development during three weeks of an aversion when 20 rad was given, 30 to 40 min later. Insulin, domperidone, haloperidol, acetylsalicylic acid, naloxone, chlorpheniramine, cimetidine, and dimethyl sulphoxide were tested without notable success. However dexamethasone, at doses ranging from 0.013 mg/kg to 1.3 mg/kg, significantly attenuated the conditioned taste aversion by up to 60 percent. The results are discussed in terms of a search for an antinauseant and antiemetic drug effective against radiation in man

  16. Roles of octopaminergic and dopaminergic neurons in appetitive and aversive memory recall in an insect

    Directory of Open Access Journals (Sweden)

    Hatano Ai

    2009-08-01

    Full Text Available Abstract Background In insect classical conditioning, octopamine (the invertebrate counterpart of noradrenaline or dopamine has been suggested to mediate reinforcing properties of appetitive or aversive unconditioned stimulus, respectively. However, the roles of octopaminergic and dopaminergic neurons in memory recall have remained unclear. Results We studied the roles of octopaminergic and dopaminergic neurons in appetitive and aversive memory recall in olfactory and visual conditioning in crickets. We found that pharmacological blockade of octopamine and dopamine receptors impaired aversive memory recall and appetitive memory recall, respectively, thereby suggesting that activation of octopaminergic and dopaminergic neurons and the resulting release of octopamine and dopamine are needed for appetitive and aversive memory recall, respectively. On the basis of this finding, we propose a new model in which it is assumed that two types of synaptic connections are formed by conditioning and are activated during memory recall, one type being connections from neurons representing conditioned stimulus to neurons inducing conditioned response and the other being connections from neurons representing conditioned stimulus to octopaminergic or dopaminergic neurons representing appetitive or aversive unconditioned stimulus, respectively. The former is called 'stimulus-response connection' and the latter is called 'stimulus-stimulus connection' by theorists studying classical conditioning in higher vertebrates. Our model predicts that pharmacological blockade of octopamine or dopamine receptors during the first stage of second-order conditioning does not impair second-order conditioning, because it impairs the formation of the stimulus-response connection but not the stimulus-stimulus connection. The results of our study with a cross-modal second-order conditioning were in full accordance with this prediction. Conclusion We suggest that insect classical

  17. Imagery Rescripting: The Impact of Conceptual and Perceptual Changes on Aversive Autobiographical Memories

    Science.gov (United States)

    Slofstra, Christien; Nauta, Maaike H.; Holmes, Emily A.; Bockting, Claudi L. H.

    2016-01-01

    Background Imagery rescripting (ImRs) is a process by which aversive autobiographical memories are rendered less unpleasant or emotional. ImRs is thought only to be effective if a change in the meaning-relevant (semantic) content of the mental image is produced, according to a cognitive hypothesis of ImRs. We propose an additional hypothesis: that ImRs can also be effective by the manipulation of perceptual features of the memory, without explicitly targeting meaning-relevant content. Methods In two experiments using a within-subjects design (both N = 48, community samples), both Conceptual-ImRs—focusing on changing meaning-relevant content—and Perceptual-ImRs—focusing on changing perceptual features—were compared to Recall-only of aversive autobiographical image-based memories. An active control condition, Recall + Attentional Breathing (Recall+AB) was added in the first experiment. In the second experiment, a Positive-ImRs condition was added—changing the aversive image into a positive image that was unrelated to the aversive autobiographical memory. Effects on the aversive memory’s unpleasantness, vividness and emotionality were investigated. Results In Experiment 1, compared to Recall-only, both Conceptual-ImRs and Perceptual-ImRs led to greater decreases in unpleasantness, and Perceptual-ImRs led to greater decreases in emotionality of memories. In Experiment 2, the effects on unpleasantness were not replicated, and both Conceptual-ImRs and Perceptual-ImRs led to greater decreases in emotionality, compared to Recall-only, as did Positive-ImRs. There were no effects on vividness, and the ImRs conditions did not differ significantly from Recall+AB. Conclusions Results suggest that, in addition to traditional forms of ImRs, targeting the meaning-relevant content of an image during ImRs, relatively simple techniques focusing on perceptual aspects or positive imagery might also yield benefits. Findings require replication and extension to clinical

  18. Sex differences in the effects of ethanol pre-exposure during adolescence on ethanol-induced conditioned taste aversion in adult rats

    OpenAIRE

    Sherrill, Luke K.; Berthold, Claire; Koss, Wendy A.; Juraska, Janice M.; Gulley, Joshua M.

    2011-01-01

    Alcohol use, which typically begins during adolescence and differs between males and females, is influenced by both the rewarding and aversive properties of the drug. One way adolescent alcohol use may modulate later consumption is by reducing alcohol s aversive properties. Here, we used a conditioned taste aversion (CTA) paradigm to determine if pre-exposure to alcohol (ethanol) during adolescence would attenuate ethanol-induced CTA assessed in adulthood in a sex-dependent manner. Male and f...

  19. Can Risk-aversion towards fertilizer explain part of the non-adoption puzzle for hybrid maize? Empirical evidence from Malawi

    OpenAIRE

    Simtowe, Franklin

    2006-01-01

    This study investigates the linkage between attitudes towards risk and adoption. We empirically examine the relative risk premium related to fertilizer-use among 404 farmers from Malawi and examine the relationship between risk aversion on fertilizer-use and the adoption of hybrid maize. Results show that Malawian farmers exhibit absolute Arrow-Pratt risk aversion towards the use of fertilizer. The findings also reveal that risk aversion towards the use of fertilizer is strongly associated wi...

  20. Accumbal dopamine, noradrenaline and serotonin activity after naloxone-conditioned place aversion in morphine-dependent mice.

    Science.gov (United States)

    Gómez-Milanés, Iván; Almela, Pilar; García-Carmona, Juan-Antonio; García-Gutiérrez, M Salud; Aracil-Fernández, Auxiliadora; Manzanares, Jorge; Milanés Maquilón, María Victoria; Laorden, M Luisa

    2012-08-01

    Dopamine (DA) neurons not only show a pattern signaling the magnitude, delay and probability of rewards but also code negative motivation and aversive events. Beside DA, other systems such as noradrenaline (NA) and serotonin (5-HT) may also be implicated in naloxone-induced conditioned place aversion (CPA; an index of the aversive consequences of withdrawal). The purpose of the present study was to evaluate: (i) the turnover of DA, NA and 5-HT in the nucleus accumbens (NAc), one of the most important substrates for aversive states, (ii) the changes in tyrosine hydroxylase (TH) gene expression in the ventral tegmental area, and (iii) total TH protein levels and TH phosphorylation in the NAc after naloxone-induced morphine withdrawal. DA, NA and 5-HT turnover was evaluated by high-performance liquid chromatography (HPLC). TH gene expression was determined by real time quantitative PCR (RT-PCR) and total TH and TH phosphorylated at Ser31 and Ser40 were analyzed by Western blot. Present results show that the aversion for environmental cues paired with opioid withdrawal was higher than that observed in the saline group treated with naloxone, which indicates that morphine pretreatment potentiated the ability of naloxone to produce place aversion. In addition, present data show that naloxone-induced CPA positively correlated with an increase of DA and NA turnover in the NAc, which paralleled an increase in TH gene expression in the VTA and TH phosphorylation and enhanced TH protein levels in the NAc. Thus, the present study indicates that naloxone-induced aversion in morphine-dependent mice enhances DA and NA activity in the NAc and suggests that transcriptional and post-transcriptional regulation of TH could be involved in the hyperactivity of mesolimbic dopaminergic system observed in morphine-withdrawn mice. PMID:22713675

  1. Stackelberg game of buyback policy in supply chain with a risk-averse retailer and a risk-averse supplier based on CVaR.

    Science.gov (United States)

    Zhou, Yanju; Chen, Qian; Chen, Xiaohong; Wang, Zongrun

    2014-01-01

    This paper considers a decentralized supply chain in which a single supplier sells a perishable product to a single retailer facing uncertain demand. We assume that the supplier and the retailer are both risk averse and utilize Conditional Value at Risk (CVaR), a risk measure method which is popularized in financial risk management, to estimate their risk attitude. We establish a buyback policy model based on Stackelberg game theory under considering supply chain members' risk preference and get the expressions of the supplier's optimal repurchase price and the retailer's optimal order quantity which are compared with those under risk neutral case. Finally, a numerical example is applied to simulate that model and prove related conclusions. PMID:25247605

  2. Stackelberg game of buyback policy in supply chain with a risk-averse retailer and a risk-averse supplier based on CVaR.

    Directory of Open Access Journals (Sweden)

    Yanju Zhou

    Full Text Available This paper considers a decentralized supply chain in which a single supplier sells a perishable product to a single retailer facing uncertain demand. We assume that the supplier and the retailer are both risk averse and utilize Conditional Value at Risk (CVaR, a risk measure method which is popularized in financial risk management, to estimate their risk attitude. We establish a buyback policy model based on Stackelberg game theory under considering supply chain members' risk preference and get the expressions of the supplier's optimal repurchase price and the retailer's optimal order quantity which are compared with those under risk neutral case. Finally, a numerical example is applied to simulate that model and prove related conclusions.

  3. Noradrenergic actions in the basolateral complex of the amygdala modulate Arc expression in hippocampal synapses and consolidation of aversive and non-aversive memory.

    Science.gov (United States)

    McReynolds, Jayme R; Anderson, Kelly M; Donowho, Kyle M; McIntyre, Christa K

    2014-11-01

    The basolateral complex of the amygdala (BLA) plays a role in the modulation of emotional memory consolidation through its interactions with other brain regions. In rats, memory enhancing infusions of the β-adrenergic receptor agonist clenbuterol into the BLA immediately after training enhances expression of the protein product of the immediate early gene Arc in the dorsal hippocampus and memory-impairing intra-BLA treatments reduce hippocampal Arc expression. We have proposed that the BLA may modulate memory consolidation through an influence on the local translation of synaptic plasticity proteins, like Arc, in recently active synapses in efferent brain regions. To date, all work related to this hypothesis is based on aversive memory tasks such as inhibitory avoidance (IA). To determine whether BLA modulation of hippocampal Arc protein expression is specific to plasticity associated with inhibitory avoidance memory, or a common mechanism for multiple types of memory, we tested the effect of intra-BLA infusions of clenbuterol on memory and hippocampal synaptic Arc expression following IA or object recognition training. Results indicate that intra-BLA infusions of clenbuterol enhance memory for both tasks; however, Arc expression in hippocampal synaptoneurosomes was significantly elevated only in rats trained on the aversive IA task. These findings suggest that regulation of Arc expression in hippocampal synapses may depend on co-activation of arousal systems. To test this hypothesis, a "high arousal" version of the OR task was used where rats were not habituated to the testing conditions. Posttraining intra-BLA infusions of clenbuterol enhanced consolidation of the high-arousing version of the task and significantly increased Arc protein levels in dorsal hippocampus synaptic fractions. These findings suggest that the BLA modulates multiple forms of memory and affects the synaptic plasticity-associated protein Arc in synapses of the dorsal hippocampus when

  4. Mediated overshadowing and potentiation of long-delay taste aversion learning: Two versus six cue-taste pairings.

    Science.gov (United States)

    Kwok, Dorothy W S; Sun, Qian; Boakes, Robert A

    2016-01-01

    Mediated overshadowing occurs when an evoked representation of one stimulus interferes with the formation of an association between two other stimuli. This study tested whether such an effect can be found in long-delay taste aversion learning. The general methodology was to pair a cue with a sour taste (hydrochloric acid [HCl]) and then introduce the cue during the delay between the target taste, sucrose, and injection with lithium chloride (LiCl). Either 2 or 6 cue-HCl pairings were given. In Experiment 1, introduction of the cue, an almond flavor, produced overshadowing of the sucrose aversion in the group given 2 cue-HCl pairings (Paired-2), relative to an unpaired control, but potentiation of the sucrose aversion in the group given 6 cue-HCl pairings (Paired-6). This confirms that few pairings can be better than many in determining whether representation-mediated effects occur (Holland, 1990). A possible explanation for the Paired-6 results is that almond evoked an aversive response rather than memory of the sour HCl and that this added to the aversion produced by the sucrose-lithium pairing. Experiment 2 obtained similar results when a context was used as the cue intended to evoke an HCl representation. PMID:26752235

  5. Maggot Debridement Therapy in the Treatment of Complex Diabetic Wounds

    OpenAIRE

    Marineau, Michelle L; Herrington, Mark T; Swenor, Karen M; Eron, Lawrence J

    2011-01-01

    The growth and aging of the population of Hawai‘i with a high incidence of diabetes mandates a need for more effective strategies to manage the healing of complicated wounds. Maggot debridement therapy (MDT) is one alternative utilized with successful results. Observations have indicated that maggots have the ability to debride wound beds, provide anti-microbial activity and also stimulate wound healing in diabetic patients. None of the patients refused MDT due to aversion of this treatment m...

  6. Integration of risk aversion in the evaluation of the external cost of a nuclear accident

    International Nuclear Information System (INIS)

    Full text of publication follows: the external costs of fuel cycles used in the production of electricity are those imposed on society and environment that are not accounted for by the producers and consumers of energy. Within the evaluation of the external cost of the nuclear fuel cycle, the evaluation of a nuclear accident has to be addressed. For this purpose, the basic approach consists in calculating the expected value of various occident scenarios. the main criticism of this approach is that there is a discrepancy between the social acceptability of the risk and the average monetary value which corresponds in principle to the compensation of the consequences for each individual of the population affected by the accident. The aim of this paper is to propose a methodology for the integration of risk aversion, relying on the expected utility approach, as well as a numerical application based on the French data for the external cost of a nuclear accident. Although a huge range of values has been published for the relative risk aversion coefficient, it seems reasonable to adopt a value of 2 for the specific case of nuclear accident. This leads to an estimated multiplying coefficient approximately equal to 20 to be applied to the expected external cost of a nuclear accident corresponding to a release of about 1% of the core. In this case, the external cost of the nuclear accident is estimated to 0.046 mECU/kWh (i.e. about 50% of the total external costs of the nuclear fuel cycle estimated at 0.1 mECU/kWh with a 3% discount rate), instead of 0.0023 mECU/kWh without taking into account risk aversion. (authors)

  7. Estimating risk aversion, Risk-Neutral and Real-World Densities using Brazilian Real currency options

    Directory of Open Access Journals (Sweden)

    José Fajardo

    2012-12-01

    Full Text Available This paper uses the Liu et al. (2007 approach to estimate the optionimplied Risk-Neutral Densities (RND, real-world density (RWD, and relative risk aversion from the Brazilian Real/US Dollar exchange rate distribution. Our empirical application uses a sample of exchange-traded Brazilian Real currency options from 1999 to 2011. Our estimated value of the relative risk aversion is around 2.7, which is in line with other articles for the Brazilian Economy. Our out-of-sample results showed that the RND has some ability to forecast the Brazilian Real exchange rate, but when we incorporate the risk aversion, the out-of-sample performance improves substantially.Este artigo usa a abordagem de Liu et al. (2007 para estimar a densidade neutra ao risco, densidade do mundo real e a aversão relativa ao risco da distribuição da taxa de câmbio Dólar/Real. Na estimação foi utilizada uma amostra de opções Dólar/Real negociadas embolsa entre 1999 e 2011. O valor estimado para a aversão relativa ao risco foi de 2,7, em linha com outros artigos que também estimaram este parâmetro para a economia brasileira. A avaliação fora da amostra mostrou que a densidade neutra ao risco possui alguma habilidade para prever a taxa de câmbio Dólar/Real, mas quando o parâmetro de aversão ao risco é incorporado, a performance fora da amostra melhora substancialmente.

  8. Do sex and age affect strategic behavior and inequity aversion in children?

    Science.gov (United States)

    Bueno-Guerra, Nereida; Leiva, David; Colell, Montserrat; Call, Josep

    2016-10-01

    The ultimatum game is commonly used to explore fairness in adults in bargaining situations. Although the changes in responses that occur during development have been investigated in children, the results have been mixed. Whereas some studies show that proposers offer more when they grow older, others indicate the opposite. Moreover, these studies are outcome-based and leave intentions out of the scene, although intentions play a relevant role in daily life. The mini-ultimatum game offers the opportunity to test both outcomes and intentions, but one major obstacle for accurately pinpointing developmental transitions in strategic behavior and inequity aversion so far has been the multiple confounds that have plagued previous studies, including different methods, small sample sizes, and reduced age differences. We administered an anonymous direct-method one-shot mini-ultimatum game to 478 6- and 10-year-old children. Strategic behavior was present at 10 years of age; older participants matched more accurately what responders would accept than younger participants. However, this was true only for older girls. No sex differences were detected in younger children. No age group seemed to consider the proposer's intentions given that the rejections of the default option were not significant across conditions. Both disadvantageous and advantageous inequity aversions were present in 6-year-olds. However, older children exhibited significantly more disadvantageous inequity aversion than younger children. This contrast made the pattern of rejection of 6-year-olds look more similar to the pattern of rejection found in adults. No sex differences were found in responders' behavior. PMID:27372561

  9. Transdiagnostic Psychiatric Symptoms and Event-Related Potentials following Rewarding and Aversive Outcomes.

    Directory of Open Access Journals (Sweden)

    Jeffrey S Bedwell

    Full Text Available There is a need for a better understanding of transdiagnostic psychiatric symptoms that relate to neurophysiological abnormalities following rewarding and aversive feedback in order to inform development of novel targeted treatments. To address this need, we examined a transdiagnostic sample of 44 adults (mean age: 35.52; 57% female, which consisted of individuals with broadly-defined schizophrenia-spectrum disorders (n = 16, bipolar disorders (n = 10, other mood and anxiety disorders (n = 5, and no history of a psychiatric disorder (n = 13. Participants completed a Pavlovian monetary reward prediction task during 32-channel electroencephalogram recording. We assessed the event-related potentials (ERPs of feedback-related negativity (FRN, feedback-related positivity (FRP, and the late positive potential (LPP, following better and worse than expected outcomes. Examination of symptom relationships using stepwise regressions across the entire sample revealed that an increase in the clinician-rated Negative Symptoms factor score from the Positive and Negative Syndrome Scale, was related to a decreased LPP amplitude during better than expected (i.e., rewarding outcomes. We also found that increased self-reported scores on the Schizotypal Personality Questionnaire (Brief-Revised Disorganized factor related to an increased FRN amplitude during worse than expected (i.e., aversive outcomes. Across the entire sample, the FRP component amplitudes did not show significant relationships to any of the symptoms examined. Analyses of the three diagnostic groups of schizophrenia-spectrum disorders, bipolar disorders, and nonpsychiatric controls did not reveal any statistically significant differences across the ERP amplitudes and conditions. These findings suggest relationships between specific neurophysiological abnormalities following rewarding and aversive outcomes and particular transdiagnostic psychiatric symptoms.

  10. Transdiagnostic Psychiatric Symptoms and Event-Related Potentials following Rewarding and Aversive Outcomes.

    Science.gov (United States)

    Bedwell, Jeffrey S; Potts, Geoffrey F; Gooding, Diane C; Trachik, Benjamin J; Chan, Chi C; Spencer, Christopher C

    2016-01-01

    There is a need for a better understanding of transdiagnostic psychiatric symptoms that relate to neurophysiological abnormalities following rewarding and aversive feedback in order to inform development of novel targeted treatments. To address this need, we examined a transdiagnostic sample of 44 adults (mean age: 35.52; 57% female), which consisted of individuals with broadly-defined schizophrenia-spectrum disorders (n = 16), bipolar disorders (n = 10), other mood and anxiety disorders (n = 5), and no history of a psychiatric disorder (n = 13). Participants completed a Pavlovian monetary reward prediction task during 32-channel electroencephalogram recording. We assessed the event-related potentials (ERPs) of feedback-related negativity (FRN), feedback-related positivity (FRP), and the late positive potential (LPP), following better and worse than expected outcomes. Examination of symptom relationships using stepwise regressions across the entire sample revealed that an increase in the clinician-rated Negative Symptoms factor score from the Positive and Negative Syndrome Scale, was related to a decreased LPP amplitude during better than expected (i.e., rewarding) outcomes. We also found that increased self-reported scores on the Schizotypal Personality Questionnaire (Brief-Revised) Disorganized factor related to an increased FRN amplitude during worse than expected (i.e., aversive) outcomes. Across the entire sample, the FRP component amplitudes did not show significant relationships to any of the symptoms examined. Analyses of the three diagnostic groups of schizophrenia-spectrum disorders, bipolar disorders, and nonpsychiatric controls did not reveal any statistically significant differences across the ERP amplitudes and conditions. These findings suggest relationships between specific neurophysiological abnormalities following rewarding and aversive outcomes and particular transdiagnostic psychiatric symptoms. PMID:27299996

  11. Age-related striatal BOLD changes without changes in behavioral loss aversion

    Directory of Open Access Journals (Sweden)

    Hans C Breiter

    2015-04-01

    Full Text Available Loss aversion (LA, the idea that negative valuations have a higher psychological impact than positive ones, is considered an important variable in consumer research. The literature on aging and behavior suggests older individuals may show more LA, although it is not clear if this is an effect of aging in general (as in the continuum from age 20 and 50 years, or of the state of older age (e.g., past age 65 years. We also have not yet identified the potential biological effects of aging on the neural processing of LA. In the current study we used a cohort of subjects with a 30 year range of ages, and performed whole brain functional MRI (fMRI to examine the ventral striatum/nucleus accumbens (VS/NAc response during a passive viewing of affective faces with model-based fMRI analysis incorporating behavioral data from a validated approach/avoidance task with the same stimuli. Our a priori focus on the VS/NAc was based on (1 the VS/NAc being a central region for reward/aversion processing, (2 its activation to both positive and negative stimuli, (3 its reported involvement with tracking LA. LA from approach/avoidance to affective faces showed excellent fidelity to published measures of LA. Imaging results were then compared to the behavioral measure of LA using the same affective faces. Although there was no relationship between age and LA, we observed increasing neural differential sensitivity (NDS of the VS/NAc to avoidance responses (negative valuations relative to approach responses (positive valuations with increasing age. These findings suggest that a central region for reward/aversion processing changes with age, and may require more activation to produce the same LA behavior as in younger individuals, consistent with the idea of neural efficiency observed with high IQ individuals showing less brain activation to complete the same task.

  12. Leucokinin mimetic elicits aversive behavior in mosquito Aedes aegypti (L.) and inhibits the sugar taste neuron.

    Science.gov (United States)

    Kwon, Hyeogsun; Ali Agha, Moutaz; Smith, Ryan C; Nachman, Ronald J; Marion-Poll, Frédéric; Pietrantonio, Patricia V

    2016-06-21

    Insect kinins (leucokinins) are multifunctional peptides acting as neurohormones and neurotransmitters. In females of the mosquito vector Aedes aegypti (L.), aedeskinins are known to stimulate fluid secretion from the renal organs (Malpighian tubules) and hindgut contractions by activating a G protein-coupled kinin receptor designated "Aedae-KR." We used protease-resistant kinin analogs 1728, 1729, and 1460 to evaluate their effects on sucrose perception and feeding behavior. In no-choice feeding bioassays (capillary feeder and plate assays), the analog 1728, which contains α-amino isobutyric acid, inhibited females from feeding on sucrose. It further induced quick fly-away or walk-away behavior following contact with the tarsi and the mouthparts. Electrophysiological recordings from single long labellar sensilla of the proboscis demonstrated that mixing the analog 1728 at 1 mM with sucrose almost completely inhibited the detection of sucrose. Aedae-KR was immunolocalized in contact chemosensory neurons in prothoracic tarsi and in sensory neurons and accessory cells of long labellar sensilla in the distal labellum. Silencing Aedae-KR by RNAi significantly reduced gene expression and eliminated the feeding-aversion behavior resulting from contact with the analog 1728, thus directly implicating the Aedae-KR in the aversion response. To our knowledge, this is the first report that kinin analogs modulate sucrose perception in any insect. The aversion to feeding elicited by analog 1728 suggests that synthetic molecules targeting the mosquito Aedae-KR in the labellum and tarsi should be investigated for the potential to discover novel feeding deterrents of mosquito vectors. PMID:27274056

  13. Loss aversion, large deviation preferences and optimal portfolio weights for some classes of return processes

    Science.gov (United States)

    Duffy, Ken; Lobunets, Olena; Suhov, Yuri

    2007-05-01

    We propose a model of a loss averse investor who aims to maximize his expected wealth under certain constraints. The constraints are that he avoids, with high probability, incurring an (suitably defined) unacceptable loss. The methodology employed comes from the theory of large deviations. We explore a number of fundamental properties of the model and illustrate its desirable features. We demonstrate its utility by analyzing assets that follow some commonly used financial return processes: Fractional Brownian Motion, Jump Diffusion, Variance Gamma and Truncated Lévy.

  14. Two Independent Mushroom Body Output Circuits Retrieve the Six Discrete Components of Drosophila Aversive Memory

    OpenAIRE

    Emna Bouzaiane; Séverine Trannoy; Lisa Scheunemann; Pierre-Yves Plaçais; Thomas Preat

    2015-01-01

    Understanding how the various memory components are encoded and how they interact to guide behavior requires knowledge of the underlying neural circuits. Currently, aversive olfactory memory in Drosophila is behaviorally subdivided into four discrete phases. Among these, short- and long-term memories rely, respectively, on the γ and α/β Kenyon cells (KCs), two distinct subsets of the ∼2,000 neurons in the mushroom body (MB). Whereas V2 efferent neurons retrieve memory from α/β KCs, the neuron...

  15. Multi-market energy procurement for a large consumer using a risk-aversion procedure

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Kazem [Tarbiat Modares University, Tehran, P.O. Box 14115-111 (Iran); Conejo, Antonio J. [Castilla-La Mancha University, Ciudad Real (Spain); Carrion, Miguel [Castilla-La Mancha University, Toledo (Spain); Moghaddam, Mohsen Parsa [Tarbiat Modares University, Tehran (Iran)

    2010-01-15

    This paper provides a technique to derive the bidding strategy in the day-ahead market of a large consumer that procures its electricity demand in both the day-ahead market and a subsequent adjustment market. Price uncertainty is modeled using concepts derived from information gap decision theory, which allows deriving robust decisions with respect to price volatility. Risk aversion is built implicitly within the proposed model. Correlations among prices in the day-ahead and the adjustment markets are properly modeled. The proposed technique is illustrated through a realistic case study. (author)

  16. Canine anxieties and phobias: an update on separation anxiety and noise aversions.

    Science.gov (United States)

    Sherman, Barbara L; Mills, Daniel S

    2008-09-01

    Companion dogs commonly experience states of anxiety, fears, and phobias. Separation anxiety and noise aversions, as discussed in this article, are especially prevalent. Veterinarians are encouraged to recognize and treat such conditions on first presentation to address welfare issues and optimize successful management. New data suggest new treatment modalities, including behavioral management, pharmacotherapy, and species-specific pheromone use. Failure to treat can result in disruption of the human-animal bond and subsequent abandonment, relinquishment, or even euthanasia of the affected dog. PMID:18672155

  17. Tax Aversion, Laffer Curve, and the Self-financing of Tax Cuts

    OpenAIRE

    2015-01-01

    High taxation is found to lead not to less labor supply but to more tax evasion and/or black labor. Investigating next what this implies for the course of the tax revenue and subsequently for the shape of the Laffer curve, this curve is found to change with the tax induced change of taxpayer preferences over tax compliance and tax aversion. Hence, the relevant Laffer curve when contemplating tax cuts should be the one after the last tax increase and cannot thereby be fully self-financed.

  18. Optimistic bias and pessimistic realism in judgments of contingency with aversive or rewarding outcomes.

    Science.gov (United States)

    Sonoda, Akihito

    2002-10-01

    A depressive personality influences judgments of contingency. This is called "depressive realism." The present experiment examined whether optimistic traits, as measured by various scales, are correlated with judgments of contingency. The valences of the target stimuli were aversive or rewarding (noise avoidance or gaining points). Analysis indicated that the optimistic subjects (as measured by explanatory style for negative events) tend to overestimate noncontingent events; however, optimism measured by other scales did not show such an effect. The findings are discussed in terms of a self-defensive attributional bias. PMID:12416837

  19. Explicit Disassociation of a Conditioned Stimulus and Unconditioned Stimulus during Extinction Training Reduces Both Time to Asymptotic Extinction and Spontaneous Recovery of a Conditioned Taste Aversion

    Science.gov (United States)

    Mickley, G. Andrew; DiSorbo, Anthony; Wilson, Gina N.; Huffman, Jennifer; Bacik, Stephanie; Hoxha, Zana; Biada, Jaclyn M.; Kim, Ye-Hyun

    2009-01-01

    Conditioned taste aversions (CTAs) may be acquired when an animal consumes a novel taste (CS) and then experiences the symptoms of poisoning (US). This aversion may be extinguished by repeated exposure to the CS alone. However, following a latency period in which the CS is not presented, the CTA will spontaneously recover (SR). In the current…

  20. High-resolution genetic mapping of the sucrose octaacetate taste aversion (Soa) locus on mouse Chromosome 6

    OpenAIRE

    Bachmanov, Alexander A.; Li, Xia; Li, Shanru; Neira, Mauricio; Gary K Beauchamp; Azen, Edwin A.

    2001-01-01

    An acetylated sugar, sucrose octaacetate (SOA), tastes bitter to humans and has an aversive taste to at least some mice and other animals. In mice, taste aversion to SOA depends on allelic variation of a single locus, Soa. Three Soa alleles determine ‘taster’ (Soaa), ‘nontaster’ (Soab), and ‘demitaster’ (Soac) phenotypes of taste sensitivity to SOA. Although Soa has been mapped to distal Chromosome (Chr) 6, the limits of the Soa region have not been defined. In this study, mice from congenic ...

  1. Coordinating Contracts for Two-Stage Fashion Supply Chain with Risk-Averse Retailer and Price-Dependent Demand

    OpenAIRE

    Minli Xu; Qiao Wang; Linhan Ouyang

    2013-01-01

    When the demand is sensitive to retail price, revenue sharing contract and two-part tariff contract have been shown to be able to coordinate supply chains with risk neutral agents. We extend the previous studies to consider a risk-averse retailer in a two-echelon fashion supply chain. Based on the classic mean-variance approach in finance, the issue of channel coordination in a fashion supply chain with risk-averse retailer and price-dependent demand is investigated. We propose both single co...

  2. Nitric Oxide in the Hippocampal Cortical Area 1 (CA1) Augments the Naloxone-induced Place Aversion

    OpenAIRE

    Mohammad-Reza Jalali Nadoushan; Manizheh Karami; Masoomeh Pirouzi

    2013-01-01

    It has been shown that naloxone induces place aversion in the conditioning task. We examined the involvement of Nitric Oxide (NO) in naloxone- induced place aversion. The experiment was conducted in male Wistar rats (weighing 200-250 g) using an unbiased conditioning program. Control group solely received saline (1 mL kg-1, i.p.) throughout the procedure. The experimental animals were injected naloxone (0.1-0.4 mg kg-1, i.p.) once per day during the phase of conditioning. L-Arginine (0.003-3 ...

  3. Impact of perennial energy crops income variability on the crop selection of risk averse farmers

    International Nuclear Information System (INIS)

    The UK Government policy is for the area of perennial energy crops in the UK to expand significantly. Farmers need to choose these crops in preference to conventional rotations for this to be achievable. This paper looks at the potential level and variability of perennial energy crop incomes and the relation to incomes from conventional arable crops. Assuming energy crop prices are correlated to oil prices the results suggests that incomes from them are not well correlated to conventional arable crop incomes. A farm scale mathematical programming model is then used to attempt to understand the affect on risk averse farmers crop selection. The inclusion of risk reduces the energy crop price required for the selection of these crops. However yields towards the highest of those predicted in the UK are still required to make them an optimal choice, suggesting only a small area of energy crops within the UK would be expected to be chosen to be grown. This must be regarded as a tentative conclusion, primarily due to high sensitivity found to crop yields, resulting in the proposal for further work to apply the model using spatially disaggregated data. - Highlights: ► Energy crop and conventional crop incomes suggested as uncorrelated. ► Diversification effect of energy crops investigated for a risk averse farmer. ► Energy crops indicated as optimal selection only on highest yielding UK sites. ► Large establishment grant rates to substantially alter crop selections.

  4. Role of the endocannabinoid 2-arachidonoylglycerol in aversive responses mediated by the dorsolateral periaqueductal grey.

    Science.gov (United States)

    Gobira, P H; Almeida-Santos, A F; Guimaraes, F S; Moreira, F A; Aguiar, D C

    2016-01-01

    2-arachidonoylglycerol (2-AG) is an endogenous ligand of the cannabinoid CB1 receptor. This endocannabinoid and its hydrolyzing enzyme, monoacylglycerol lipase (MAGL), are present in encephalic regions related to psychiatric disorders, including the midbrain dorsolateral periaqueductal grey (dlPAG). The dlPAG is implicated in panic disorder and its stimulation results in defensive responses proposed as a model of panic attacks. The present work verified if facilitation of 2-AG signalling in the dlPAG counteracts panic-like responses induced by local chemical stimulation. Intra-dlPAG injection of 2-AG prevented panic-like response induced by the excitatory amino acid N-methyl-d-aspartate (NMDA). This effect was mimicked by the 2-AG hydrolysis inhibitor (MAGL preferring inhibitor) URB602. The anti-aversive effect of URB602 was reversed by the CB1 receptor antagonist, AM251. Additionally, a combination of sub-effective doses of 2-AG and URB602 also prevented NMDA-induced panic-like response. Finally, immunofluorescence assay showed a significant increase in c-Fos positive cells in the dlPAG after local administration of NMDA. This response was also prevented by URB602. These data support the hypothesis that 2-AG participates in anti-aversive mechanisms in the dlPAG and reinforce the proposal that facilitation of endocannabinoid signalling could be a putative target for developing additional treatments against panic and other anxiety-related disorders. PMID:26628106

  5. fMRI evidence of a hot-cold empathy gapin hypothetical and real aversive choices

    Directory of Open Access Journals (Sweden)

    Min Jeong Kang

    2013-06-01

    Full Text Available Hypothetical bias is the common finding that hypothetical monetary values for goods are higher than real values. We extend this research to the domain of bads such as consumer and household choices made to avoid aversive outcomes (e.g., insurance. Previous evidence of hot-cold empathy gaps suggest food disgust is likely to be strongly underestimated in hypothetical (cold choice. Depending on relative underestimation of food disgust and pain of spending, the hypothetical bias for aversive bads can go in the typical direction for goods, disappear, or reverse in sign. We find that the bias is reversed in sign—subjects pay more to avoid bads when choice is real. fMRI shows that real choice more strongly activates striatum and medial prefrontal cortex (reward regions and shows distinct activity in insula and amygdala (disgust and fear regions. The neural findings suggest ways to exogeneously manipulate or record brain activity in order to create better forecasts of actual consumer choice.

  6. Cue-elicited food seeking is eliminated with aversive outcomes following outcome devaluation.

    Science.gov (United States)

    Eder, Andreas B; Dignath, David

    2016-01-01

    In outcome-selective Pavlovian-to-instrumental transfer (PIT), stimuli that are predictive of specific outcomes prime instrumental responses that are associated with these outcomes. Previous human studies yielded mixed evidence in respect to whether the PIT effect is affected by a posttraining devaluation of an outcome, with the PIT effect being preserved after a devaluation of a primary reinforcer (food, drugs) but not following the devaluation of a secondary reinforcer (money). The present research examined whether outcome-selective transfer is eliminated when the devaluation of a primary (liquid) reinforcer is strong and aversive. Experiment 1 confirmed these expectations following a devaluation with bad tasting Tween 20. However, outcome-selective transfer was still observed when the earned (devalued) outcome was not consumed immediately after each test (Experiment 2). These results suggest that the capacity of a Pavlovian cue to motivate a specific response is affected by the incentive value of the shared outcome only when the devaluation yields an aversive outcome that is consumed immediately. PMID:26089111

  7. Redundancy of visual information in aversive conditioning: Rol of the superior colliculus

    Directory of Open Access Journals (Sweden)

    Cardenas, Fernando P

    2009-06-01

    Full Text Available A relevant feature of biological systems is the parallel or distributed processing. This kind of information processing ensures a functional redundancy which serves as a mechanism for allowing a functional level even in the absence of some regions of the system. In the case of the visual system the parallel processing relies on three simultaneous pathways, each one of them carrying out certain aspects of visual information processing. The collicular branch of this parallel system is related to emotional aspects. The collicular pathway transmits information from the superior colliculus to the amygdala, via the suprageniculate nucleus. Here we assess the effect of the temporal inhibition of the superior colliculus on the acquisition of a classical aversive conditioning. For this Wistar rats received a intracollicular microinjection of lidocaine (1% immediately before the training session. Our results clearly showed that the superior colliculus in not the main structure required to the acquisition of this kind of associative learning. This suggests that other subcortical structures must be responsible for relaying information to the amygdala in order to allow the aversive conditioning acquisition. From this, new possibilities are open to study a probable way to understand the redundant properties of the mammal visual system.

  8. Innate Predator Odor Aversion Driven by Parallel Olfactory Subsystems that Converge in the Ventromedial Hypothalamus.

    Science.gov (United States)

    Pérez-Gómez, Anabel; Bleymehl, Katherin; Stein, Benjamin; Pyrski, Martina; Birnbaumer, Lutz; Munger, Steven D; Leinders-Zufall, Trese; Zufall, Frank; Chamero, Pablo

    2015-05-18

    The existence of innate predator aversion evoked by predator-derived chemostimuli called kairomones offers a strong selective advantage for potential prey animals. However, it is unclear how chemically diverse kairomones can elicit similar avoidance behaviors. Using a combination of behavioral analyses and single-cell Ca(2+) imaging in wild-type and gene-targeted mice, we show that innate predator-evoked avoidance is driven by parallel, non-redundant processing of volatile and nonvolatile kairomones through the activation of multiple olfactory subsystems including the Grueneberg ganglion, the vomeronasal organ, and chemosensory neurons within the main olfactory epithelium. Perturbation of chemosensory responses in specific subsystems through disruption of genes encoding key sensory transduction proteins (Cnga3, Gnao1) or by surgical axotomy abolished avoidance behaviors and/or cellular Ca(2+) responses to different predator odors. Stimulation of these different subsystems resulted in the activation of widely distributed target regions in the olfactory bulb, as assessed by c-Fos expression. However, in each case, this c-Fos increase was observed within the same subnuclei of the medial amygdala and ventromedial hypothalamus, regions implicated in fear, anxiety, and defensive behaviors. Thus, the mammalian olfactory system has evolved multiple, parallel mechanisms for kairomone detection that converge in the brain to facilitate a common behavioral response. Our findings provide significant insights into the genetic substrates and circuit logic of predator-driven innate aversion and may serve as a valuable model for studying instinctive fear and human emotional and panic disorders. PMID:25936549

  9. Early adversity disrupts the adult use of aversive prediction errors to reduce fear in uncertainty

    Directory of Open Access Journals (Sweden)

    Kristina M Wright

    2015-08-01

    Full Text Available Early life adversity increases anxiety in adult rodents and primates, and increases the risk for developing post-traumatic disorder (PTSD in humans. We hypothesized that early adversity impairs the use of learning signals – negative, aversive prediction errors – to reduce fear in uncertainty. To test this hypothesis, we gave adolescent rats a battery of adverse experiences then assessed adult performance in probabilistic Pavlovian fear conditioning and fear extinction. Rats were confronted with three cues associated with different probabilities of foot shock: one cue never predicted shock, another cue predicted shock with uncertainty, and a final cue always predicted shock. Control rats initially acquired fear to all cues, but rapidly reduced fear to the non-predictive and uncertain cues. Early adversity rats were slower to reduce fear to the non-predictive cue and never fully reduced fear to the uncertain cue. In extinction, all cues were presented in the absence of shock. Fear to the uncertain cue in discrimination, but not early adversity itself, predicted the reduction of fear in extinction. These results demonstrate early adversity impairs the use of negative, aversive prediction errors to reduce fear, especially in situations of uncertainty.

  10. Delay and reward choice in ADHD: an experimental test of the role of delay aversion.

    Science.gov (United States)

    Marco, Rafaela; Miranda, Ana; Schlotz, Wolff; Melia, Amanda; Mulligan, Aisling; Müller, Ueli; Andreou, Penny; Butler, Louise; Christiansen, Hanna; Gabriels, Isabel; Medad, Sheera; Albrecht, Bjorn; Uebel, Henrik; Asherson, Phillip; Banaschewski, Tobias; Gill, Michael; Kuntsi, Jonna; Mulas, Fernando; Oades, Robert; Roeyers, Herbert; Steinhausen, Hans-Christoph; Rothenberger, Aribert; Faraone, Stephen V; Sonuga-Barke, Edmund J S

    2009-05-01

    Children with attention deficit/hyperactivity disorder (ADHD) choose smaller sooner (SS) over larger later (LL) rewards more than controls. Here we assess the contributions of impulsive drive for immediate rewards (IDIR) and delay aversion (DAv) to this pattern. We also explore the characteristics of, and the degree of familiality in, ADHD SS responders. We had 360 ADHD probands; 349 siblings and 112 controls (aged between 6 to 17 years) chose between SS (1 point after 2 s) and LL reward (2 points after 30 s) outcomes on the Maudsley Index of Delay Aversion (Kuntsi, Oosterlaan, & Stevenson, 2001): Under one condition SS choice led to less overall trial delay under another it did not. ADHD participants chose SS more than controls under both conditions. This effect was larger when SS choice reduced trial delay. ADHD SS responders were younger, had lower IQ, more conduct disorder and had siblings who were more likely to be SS responders themselves. The results support a dual component model in which both IDIR and DAv contribute to SS choice in ADHD. SS choice may be a marker of an ADHD motivational subtype. PMID:19413450

  11. Consequences of repeated ethanol exposure during early or late adolescence on conditioned taste aversions in rats

    Directory of Open Access Journals (Sweden)

    Jessica Saalfield

    2015-12-01

    Full Text Available Alcohol use is prevalent during adolescence, yet little is known about possible long-lasting consequences. Recent evidence suggests that adolescents are less sensitive than adults to ethanol's aversive effects, an insensitivity that may be retained into adulthood after repeated adolescent ethanol exposure. This study assessed whether intermittent ethanol exposure during early or late adolescence (early-AIE or late-AIE, respectively would affect ethanol conditioned taste aversions 2 days (CTA1 and >3 weeks (CTA2 post-exposure using supersaccharin and saline as conditioning stimuli (CS, respectively. Pair-housed male Sprague-Dawley rats received 4 g/kg i.g. ethanol (25% or water every 48 h from postnatal day (P 25–45 (early AIE or P45-65 (late AIE, or were left non-manipulated (NM. During conditioning, 30 min home cage access to the CS was followed by 0, 1, 1.5, 2 or 2.5 g/kg ethanol i.p., with testing 2 days later. Attenuated CTA relative to controls was seen among early and late AIE animals at both CTA1 and CTA2, an effect particularly pronounced at CTA1 after late AIE. Thus, adolescent exposure to ethanol was found to induce an insensitivity to ethanol CTA seen soon after exposure and lasting into adulthood, and evident with ethanol exposures not only early but also later in adolescence.

  12. Scheduling of a hydro producer considering head-dependency, price scenarios and risk-aversion

    International Nuclear Information System (INIS)

    Highlights: ► A MIQP approach is proposed for the short-term hydro scheduling problem. ► Head-dependency, discontinuous operating regions and discharge ramping constraints are considered. ► As new contribution to earlier studies, market uncertainty is introduced in the model via price scenarios. ► Also, risk aversion is incorporated by limiting the volatility of the expected profit through CVaR. ► A case study based on one of the main Portuguese cascaded hydro systems is provided. - Abstract: In this paper, a mixed-integer quadratic programming approach is proposed for the short-term hydro scheduling problem, considering head-dependency, discontinuous operating regions and discharge ramping constraints. As new contributions to earlier studies, market uncertainty is introduced in the model via price scenarios, and risk aversion is also incorporated by limiting the volatility of the expected profit through the conditional value-at-risk. Our approach has been applied successfully to solve a case study based on one of the main Portuguese cascaded hydro systems, requiring a negligible computational time.

  13. Effects of dose and of partial body ionizing radiation on taste aversion learning in rats with lesions of the area postrema

    International Nuclear Information System (INIS)

    The effect of area postrema lesions on the acquisition of a conditioned taste aversion following partial body exposure to ionizing radiation was investigated in rats exposed to head-only irradiation at 100, 200 and 300 rad or to body-only irradiation at 100 and 200 rad. Following head-only irradiation area postrema lesions produced a significant attenuation of the radiation-induced taste aversion at all dose levels, although the rats still showed a significant reduction in sucrose preference. Following body-only exposure, area postrema lesions completely disrupted the acquisition of the conditioned taste aversion. The results are interpreted as indicating that: (a) the acquisition of a conditioned taste aversion following body-only exposure is mediated by the area postrema; and (b) taste aversion learning following radiation exposure to the head-only is mediated by both the area postrema and a mechanism which is independent of the area postrema

  14. Enhancing the Efficacy of Teacher Incentives through Loss Aversion: A Field Experiment. NBER Working Paper No. 18237

    Science.gov (United States)

    Fryer, Roland G., Jr.; Levitt, Steven D.; List, John; Sadoff, Sally

    2012-01-01

    Domestic attempts to use financial incentives for teachers to increase student achievement have been ineffective. In this paper, we demonstrate that exploiting the power of loss aversion--teachers are paid in advance and asked to give back the money if their students do not improve sufficiently--increases math test scores between 0.201 (0.076) and…

  15. Algorithms for Probabilistically-Constrained Models of Risk-Averse Stochastic Optimization with Black-Box Distributions

    CERN Document Server

    Swamy, Chaitanya

    2008-01-01

    We consider various stochastic models that incorporate the notion of risk-averseness into the standard 2-stage recourse model, and develop novel techniques for solving the algorithmic problems arising in these models. A key notable feature of our work that distinguishes it from work in some other related models, such as the (standard) budget model and the (demand-) robust model, is that we obtain results in the black-box setting, that is, where one is given only sampling access to the underlying distribution. Our first model, which we call the risk-averse budget model, incorporates the notion of risk-averseness via a probabilistic constraint that restricts the probability (according to the underlying distribution) with which the second-stage cost may exceed a given budget B to at most a given input threshold \\rho. We also a consider a closely-related model that we call the risk-averse robust model, where we seek to minimize the first-stage cost and the (1-\\rho)-quantile of the second-stage cost. We obtain app...

  16. Effects of Aversive Stimuli beyond Defensive Neural Circuits: Reduced Excitability in an Identified Neuron Critical for Feeding in "Aplysia"

    Science.gov (United States)

    Shields-Johnson, Maria E.; Hernandez, John S.; Torno, Cody; Adams, Katherine M.; Wainwright, Marcy L.; Mozzachiodi, Riccardo

    2013-01-01

    In "Aplysia," repeated trials of aversive stimuli produce long-term sensitization (LTS) of defensive reflexes and suppression of feeding. Whereas the cellular underpinnings of LTS have been characterized, the mechanisms of feeding suppression remained unknown. Here, we report that LTS training induced a long-term decrease in the excitability of…

  17. Assessment of aversion to different concentrations of CO2 gas by weaned pigs using an approach-avoidance paradigm

    Science.gov (United States)

    The objective of this study was to examine the aversiveness of carbon dioxide (CO2) to weaned pigs using approach-avoidance and condition place avoidance paradigms. A preference-testing device was custom designed with two connected chambers maintained at static gas concentrations. The control chambe...

  18. Dynamic Estimation of Volatility Risk Premia and Investor Risk Aversion from Option-Implied and Realized Volatilities

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Gibson, Michael; Zhou, Hao

    This paper proposes a method for constructing a volatility risk premium, or investor risk aversion, index. The method is intuitive and simple to implement, relying on the sample moments of the recently popularized model-free realized and option-implied volatility measures. A small-scale Monte Carlo...

  19. Hippocampal Erk Mechanisms Linking Prediction Error to Fear Extinction: Roles of Shock Expectancy and Contextual Aversive Valence

    Science.gov (United States)

    Huh, Kyu Hwan; Guzman, Yomayra F.; Tronson, Natalie C.; Guedea, Anita L.; Gao, Can; Radulovic, Jelena

    2009-01-01

    Extinction of fear requires learning that anticipated aversive events no longer occur. Animal models reveal that sustained phosphorylation of the extracellular signal-regulated kinase (Erk) in hippocampal CA1 neurons plays an important role in this process. However, the key signals triggering and regulating the activity of Erk are not known. By…

  20. AAB and ABA Renewal as a Function of the Number of Extinction Trials in Conditioned Taste Aversion

    Science.gov (United States)

    Rosas, Juan M.; Garcia-Gutierrez, Ana; Callejas-Aguilera, Jose E.

    2007-01-01

    Three experiments explored renewal in conditioned taste aversion after different amounts of extinction. In Experiment 1, three groups of rats received a single conditioning trial where a saccharin solution was paired with LiCl, followed by 3 extinction trials, and a two-trial test. Groups differed in the context where they received each of the…

  1. Environmental and Economic Optimization Model for Electric System Planning in Ningxia, China: Inexact Stochastic Risk-Aversion Programming Approach

    Directory of Open Access Journals (Sweden)

    L. Ji

    2015-01-01

    Full Text Available The main goal of this paper is to provide a novel risk aversion model for long-term electric power system planning from the manager’s perspective with the consideration of various uncertainties. In the proposed method, interval parameter programming and two-stage stochastic programming are integrated to deal with the technical, economics, and policy uncertainties. Moreover, downside risk theory is introduced to balance the trade-off between the profit and risk according to the decision-maker’s risk aversion attitude. To verify the effectiveness and practical application of this approach, an inexact stochastic risk aversion model is developed for regional electric system planning and management in Ningxia Hui Autonomous Region, China. The series of solutions provide the decision-maker with the optimal investment strategy and operation management under different future emission reduction scenarios and risk-aversion levels. The results indicated that pollution control devices are still the main measures to achieve the current mitigation goal and the adjustment of generation structure would play an important role in the future cleaner electricity system with the stricter environmental policy. In addition, the model can be used for generating decision alternatives and helping decision-makers identify desired energy structure adjustment and pollutants/carbon mitigation abatement policies under various economic and system-reliability constraints.

  2. Lossed in Translation: An Off-the-Shelf Method to Recover Probabilistic Beliefs from Loss-Averse Agents

    NARCIS (Netherlands)

    T. Offerman; A. Palley

    2013-01-01

    Although strictly proper rules are designed to truthfully elicit subjective probabilistic beliefs, experimental results have shown that risk aversion causes agents to bias their reports towards the rule's baseline probability of 1/2, and a conservative preference for certain outcomes leads agents wi

  3. Studies on the role of central histamine in the acquisition of a radiation-induced conditioned taste aversion

    International Nuclear Information System (INIS)

    The experiments described in this report were designed to test two hypotheses about how exposure to low-level radiation can affect the behavior of an organism: first, tht radiation effects on behavior are mediated by a radiation-induced release of histamine; and second, that this radiation-induced histamine release can exert relatively direct effects on the central nervous system. The results of the first experiment showed that microinjection of histamine directly into the fourth ventricle of rats produced a taste aversion to a novel sucrose solution. Pretreating rats with intraventricular H1 or H2 blockers was not effective in preventing the acquisition of the radiation-induced aversion, although the H1 blocker did prevent the acquisition of a histamine-induced taste aversion. It also was not possible to establish a cross-tolerance between centrally administered histamine and radiation. The results are interpreted as not supporting the hypothesis that a radiation-induced release of central histamine mediates the acquisition of a conditioned taste aversion following exposure to low-level radiation

  4. Systemic 5-Bromo-2-Deoxyuridine Induces Conditioned Flavor Aversion and C-Fos in the Visceral Neuraxis

    Science.gov (United States)

    Kimbrough, Adam; Kwon, Bumsup; Eckel, Lisa A.; Houpt, Thomas A.

    2011-01-01

    5-bromo-2-deoxyuridine (BrdU) is often used in studies of adult neurogenesis and olfactory learning, but it can also have toxic effects on highly proliferative tissue. We found that pairing Kool-Aid flavors with acute systemic injections of BrdU induced strong conditioned flavor aversions. Intermittent injections during Kool-Aid-glucose…

  5. Aversive responses of white-tailed deer,Odocoileus virginianus, to predator urines.

    Science.gov (United States)

    Swihart, R K; Pignatello, J J; Mattina, M J

    1991-04-01

    We tested whether predator odors could reduce winter browsing of woody plants by white-tailed deer (Odocoileus virginianus). Urine from bobcats (Lyra rufus) and coyotes (Canis latrans) significantly reduced browsing of Japanese yews (Taxus cuspidata), and repellency was enhanced when urine was reapplied weekly as a topical spray. Urine of cottontail rabbits (Sylvilagus floridanus) and humans did not reduce damage, suggesting that deer do not respond aversively to odors of nonpredatory mammals or occasional predators with which they lack a long evolutionary association. Bobcat and coyote urine were more effective in tests conducted with eastern hemlock (Tsuga canadensis), which is less palatable to white-tailed deer than Japanese yew. A dichloromethane extract of bobcat urine was as effective as unextracted urine in reducing damage to hemlocks. Testing of the organic components of bobcat urine, particularly the volatile components, may enable identification of the compounds responsible for the repellency we observed. PMID:24258921

  6. Personal finance and life insurance under separation of risk aversion and elasticity of substitution

    DEFF Research Database (Denmark)

    Jensen, Ninna Reitzel; Steffensen, Mogens

    2015-01-01

    aversion from elasticity of inter-temporal substitution, we introduce certainty equivalents. We propose a time-inconsistent global optimization problem, and we present a verification theorem for an equilibrium control. In the special case without mortality risk, we discover that our optimization approach...... is equivalent to recursive utility optimization with Epstein–Zin preferences in the sense that the two approaches lead to the same result. We find this interesting since our optimization problem has an intuitive interpretation as a global maximization of certainty equivalents and since recursive...... utility, in contrast to our approach, gives rise to severe differentiability problems. Also, our optimization approach can there be seen as a generalization of recursive utility optimization with Epstein–Zin preferences to include mortality risk and life insurance....

  7. In uncertainty we trust: a median voter model with risk aversion

    Directory of Open Access Journals (Sweden)

    Pavel A. Yakovlev

    2011-12-01

    Full Text Available The principal-agent problem and uncertainty are some of the key factors affecting financial and political markets. Fear of the unknown plays an important role in human decision making, including voting. This article describes a theoretical model where voter risk aversion towards uncertainty gives political incumbents a significant advantage over their challengers, exacerbating the principal-agent problem between voters and legislators. The model presented predicts that a rise in voter uncertainty concerning the challenger allows the incumbent to deviate from the median voter’s policy preference without losing the election. This model reconciles the paradoxical coexistence of ideological shirking and high incumbent reelection rates without abandoning the elegant median voter framework.

  8. Altered frontocingulate activation during aversive interoceptive processing in young adults transitioning to problem stimulant use

    Directory of Open Access Journals (Sweden)

    Jennifer Lorraine Stewart

    2013-11-01

    Full Text Available Problems associated with stimulant use have been linked to frontocingulate, insular, and thalamic dysfunction during decision-making and alterations in interoceptive processing. However, little is known about how interoception and decision-making interact and contribute to dysfunctions that promote the transition from recreational drug use to abuse or dependence. Here, we investigate brain activation in response to reward, punishment, and uncertainty during an aversive interoceptive challenge in current and former stimulant (cocaine and amphetamine users using functional magnetic resonance imaging (fMRI. Young adults previously identified as recreational users (n=184 were followed up three years later. Of these, 18 individuals progressed to problem stimulant use (PSU, whereas 15 desisted stimulant use (DSU. PSU, DSU, and 14 healthy comparison subjects (CTL performed a two-choice prediction task at three fixed error rates (20%=reward, 50%=uncertainty, 80%=punishment during which they anticipated and experienced episodes of inspiratory breathing load. Although groups did not differ in insula activation or subjective breathing load ratings, PSU exhibited lower right inferior frontal gyrus (IFG and bilateral anterior cingulate (ACC activation than DSU and CTL during aversive interoceptive processing as well as lower right IFG in response to decision making involving uncertainty. However, PSU exhibited greater bilateral IFG activation than DSU and CTL while making choices within the context of punishing feedback, and both PSU and DSU showed lower thalamic activation during breathing load than CTL. Findings suggest that frontocingulate attenuation, reflecting reduced resources devoted to goal maintenance and action selection in the presence of uncertainty and interoceptive perturbations, may be a biomarker for susceptibility to problem stimulant use.

  9. Drug predictive cues activate aversion-sensitive striatal neurons that encode drug seeking.

    Science.gov (United States)

    Wheeler, Daniel S; Robble, Mykel A; Hebron, Emily M; Dupont, Matthew J; Ebben, Amanda L; Wheeler, Robert A

    2015-05-01

    Drug-associated cues have profound effects on an addict's emotional state and drug-seeking behavior. Although this influence must involve the motivational neural system that initiates and encodes the drug-seeking act, surprisingly little is known about the nature of such physiological events and their motivational consequences. Three experiments investigated the effect of a cocaine-predictive stimulus on dopamine signaling, neuronal activity, and reinstatement of cocaine seeking. In all experiments, rats were divided into two groups (paired and unpaired), and trained to self-administer cocaine in the presence of a tone that signaled the immediate availability of the drug. For rats in the paired group, self-administration sessions were preceded by a taste cue that signaled delayed drug availability. Assessments of hedonic responses indicated that this delay cue became aversive during training. Both the self-administration behavior and the immediate cue were subsequently extinguished in the absence of cocaine. After extinction of self-administration behavior, the presentation of the aversive delay cue reinstated drug seeking. In vivo electrophysiology and voltammetry recordings in the nucleus accumbens measured the neural responses to both the delay and immediate drug cues after extinction. Interestingly, the presentation of the delay cue simultaneously decreased dopamine signaling and increased excitatory encoding of the immediate cue. Most importantly, the delay cue selectively enhanced the baseline activity of neurons that would later encode drug seeking. Together these observations reveal how cocaine cues can modulate not only affective state, but also the neurochemical and downstream neurophysiological environment of striatal circuits in a manner that promotes drug seeking. PMID:25948270

  10. GABAA receptor drugs and neuronal plasticity in reward and aversion: focus on the ventral tegmental area

    Directory of Open Access Journals (Sweden)

    Elena eVashchinkina

    2014-11-01

    Full Text Available GABAA receptors are the main fast inhibitory neurotransmitter receptors in the mammalian brain, and targets for many clinically important drugs widely used in the treatment of anxiety disorders, insomnia and in anesthesia. Nonetheless, there are significant risks associated with the long-term use of these drugs particularly related to development of tolerance and addiction. Addictive mechanisms of GABAA receptor drugs are poorly known, but recent findings suggest that those drugs may induce aberrant neuroadaptations in the brain reward circuitry. Recently, benzodiazepines, acting on synaptic GABAA receptors, and modulators of extrasynaptic GABAA receptors (THIP and neurosteroids have been found to induce plasticity in the ventral tegmental area (VTA dopamine neurons and their main target projections. Furthermore, depending whether synaptic or extrasynaptic GABAA receptor populations are activated, the behavioral outcome of repeated administration seems to correlate with rewarding or aversive behavioral responses, respectively. The VTA dopamine neurons project to forebrain centers such as the nucleus accumbens and medial prefrontal cortex, and receive afferent projections from these brain regions and especially from the extended amygdala and lateral habenula, forming the major part of the reward and aversion circuitry. Both synaptic and extrasynaptic GABAA drugs inhibit the VTA GABAergic interneurons, thus activating the VTA DA neurons by disinhibition and this way inducing glutamatergic synaptic plasticity. However, the GABAA drugs failed to alter synaptic spine numbers as studied from Golgi-Cox-stained VTA dendrites. Since the GABAergic drugs are known to depress the brain metabolism and gene expression, their likely way of inducing neuroplasticity in mature neurons is by disinhibiting the principal neurons, which remains to be rigorously tested for a number of clinically important anxiolytics, sedatives and anesthetics in different parts of

  11. Neural activation during processing of aversive faces predicts treatment outcome in alcoholism.

    Science.gov (United States)

    Charlet, Katrin; Schlagenhauf, Florian; Richter, Anne; Naundorf, Karina; Dornhof, Lina; Weinfurtner, Christopher E J; König, Friederike; Walaszek, Bernadeta; Schubert, Florian; Müller, Christian A; Gutwinski, Stefan; Seissinger, Annette; Schmitz, Lioba; Walter, Henrik; Beck, Anne; Gallinat, Jürgen; Kiefer, Falk; Heinz, Andreas

    2014-05-01

    Neuropsychological studies reported decoding deficits of emotional facial expressions in alcohol-dependent patients, and imaging studies revealed reduced prefrontal and limbic activation during emotional face processing. However, it remains unclear whether this reduced neural activation is mediated by alcohol-associated volume reductions and whether it interacts with treatment outcome. We combined analyses of neural activation during an aversive face-cue-comparison task and local gray matter volumes (GM) using Biological Parametric Mapping in 33 detoxified alcohol-dependent patients and 33 matched healthy controls. Alcoholics displayed reduced activation toward aversive faces-neutral shapes in bilateral fusiform gyrus [FG; Brodmann areas (BA) 18/19], right middle frontal gyrus (BA46/47), right inferior parietal gyrus (BA7) and left cerebellum compared with controls, which were explained by GM differences (except for cerebellum). Enhanced functional activation in patients versus controls was found in left rostral anterior cingulate cortex (ACC) and medial frontal gyrus (BA10/11), even after GM reduction control. Increased ACC activation correlated significantly with less (previous) lifetime alcohol intake [Lifetime Drinking History (LDH)], longer abstinence and less subsequent binge drinking in patients. High LDH appear to impair treatment outcome via its neurotoxicity on ACC integrity. Thus, high activation of the rostral ACC elicited by affective faces appears to be a resilience factor predicting better treatment outcome. Although no group differences were found, increased FG activation correlated with patients' higher LDH. Because high LDH correlated with worse task performance for facial stimuli in patients, elevated activation in the fusiform 'face' area may reflect inefficient compensatory activation. Therapeutic interventions (e.g. emotion evaluation training) may enable patients to cope with social stress and to decrease relapses after detoxification. PMID

  12. Innovation and risk-averse firms: Options on carbon allowances as a hedging tool

    International Nuclear Information System (INIS)

    In a regulated world where government seeks to decarbonize the energy sector, firms face both indirect and direct costs of emitting CO2. This study seeks to take the perspective of the firm, which needs to maximize profits implying minimization of (carbon) cost as well. In this study, the firm can compose the cost-optimal portfolio of (a) investing into carbon-saving technology, which is currently expensive, (b) investing into carbon-saving technology R and D and adopt this technology at a later point, (c) buying allowances per ton of emitted CO2 in a carbon market (alternatively this could be formulated as a tax), and (d) buying offsets traded in the same market, which are based on reduced emissions from deforestation and degradation (REDD+). Uncertainties in the cost of carbon coming from a lack of commitment in policy-making leading to fluctuations in markets and uncertainty in the payoff of R and D activities could provide disincentives to incur large up-front sunk cost and raise the economic value of being flexible. We apply a real options approach with stochastic carbon-saving technology costs and stochastic CO2 costs. Assuming that firms are risk-averse, they will not only value flexibility, but also risk reductions from diversification over the different (carbon mitigation) options. - Highlights: • We study the compliance problem of a private firm under both regulatory and technological uncertainty in an optimal control setting. • When firms are risk-averse, forest-backed offset options will be part of the compliance portfolio. • R and D creates valuable options on new technology

  13. Gender differences in sleep deprivation effects on risk and inequality aversion: evidence from an economic experiment.

    Directory of Open Access Journals (Sweden)

    Michele Ferrara

    Full Text Available Excessive working hours--even at night--are becoming increasingly common in our modern 24/7 society. The prefrontal cortex (PFC is particularly vulnerable to the effects of sleep loss and, consequently, the specific behaviors subserved by the functional integrity of the PFC, such as risk-taking and pro-social behavior, may be affected significantly. This paper seeks to assess the effects of one night of sleep deprivation on subjects' risk and social preferences, which are probably the most explored behavioral domains in the tradition of Experimental Economics. This novel cross-over study employs thirty-two university students (gender-balanced participating to 2 counterbalanced laboratory sessions in which they perform standard risk and social preference elicitation protocols. One session was after one night of undisturbed sleep at home, and the other was after one night of sleep deprivation in the laboratory. Sleep deprivation causes increased sleepiness and decreased alertness in all subjects. After sleep loss males make riskier decisions compared to the rested condition, while females do the opposite. Females likewise show decreased inequity aversion after sleep deprivation. As for the relationship between cognitive ability and economic decisions, sleep deprived individuals with higher cognitive reflection show lower risk aversion and more altruistic behavior. These results show that one night of sleep deprivation alters economic behavior in a gender-sensitive way. Females' reaction to sleep deprivation, characterized by reduced risky choices and increased egoism compared to males, may be related to intrinsic psychological gender differences, such as in the way men and women weigh up probabilities in their decision-making, and/or to the different neurofunctional substrate of their decision-making.

  14. Quantifying uncertainty in pest risk maps and assessments: adopting a risk-averse decision maker’s perspective

    Directory of Open Access Journals (Sweden)

    Denys Yemshanov

    2013-09-01

    Full Text Available Pest risk maps are important decision support tools when devising strategies to minimize introductions of invasive organisms and mitigate their impacts. When possible management responses to an invader include costly or socially sensitive activities, decision-makers tend to follow a more certain (i.e., risk-averse course of action. We presented a new mapping technique that assesses pest invasion risk from the perspective of a risk-averse decision maker.We demonstrated the method by evaluating the likelihood that an invasive forest pest will be transported to one of the U.S. states or Canadian provinces in infested firewood by visitors to U.S. federal campgrounds. We tested the impact of the risk aversion assumption using distributions of plausible pest arrival scenarios generated with a geographically explicit model developed from data documenting camper travel across the study area. Next, we prioritized regions of high and low pest arrival risk via application of two stochastic ordering techniques that employed, respectively, first- and second-degree stochastic dominance rules, the latter of which incorporated the notion of risk aversion. We then identified regions in the study area where the pest risk value changed considerably after incorporating risk aversion.While both methods identified similar areas of highest and lowest risk, they differed in how they demarcated moderate-risk areas. In general, the second-order stochastic dominance method assigned lower risk rankings to moderate-risk areas. Overall, this new method offers a better strategy to deal with the uncertainty typically associated with risk assessments and provides a tractable way to incorporate decision-making preferences into final risk estimates, and thus helps to better align these estimates with particular decision-making scenarios about a pest organism of concern. Incorporation of risk aversion also helps prioritize the set of locations to target for inspections and

  15. Nurses and subordination: a historical study of mental nurses' perceptions on administering aversion therapy for 'sexual deviations'.

    Science.gov (United States)

    Dickinson, Tommy; Cook, Matt; Playle, John; Hallett, Christine

    2014-12-01

    This study aimed to examine the meanings that nurses attached to the 'treatments' administered to cure 'sexual deviation' (SD) in the UK, 1935-1974. In the UK, homosexuality was considered a classifiable mental illness that could be 'cured' until 1992. Nurses were involved in administering painful and distressing treatments. The study is based on oral history interviews with fifteen nurses who had administered treatments to cure individuals of their SD. The interviews were transcribed for historical interpretation. Some nurses believed that their role was to passively follow any orders they had been given. Other nurses limited their culpability concerning administering these treatments by adopting dehumanising and objectifying language and by focussing on administrative tasks, rather than the human beings in need of their care. Meanwhile, some nurses genuinely believed that they were acting beneficently by administering these distinctly unpleasant treatments. It is envisaged that this study might act to reiterate the need for nurses to ensure their interventions have a sound evidence base and that they constantly reflect on the moral and value base of their practice and the influence that science and societal norms can have on changing views of what is considered 'acceptable practice'. PMID:23876127

  16. The dorsal medial prefrontal (anterior cingulate) cortex–amygdala aversive amplification circuit in unmedicated generalised and social anxiety disorders: an observational study

    OpenAIRE

    Robinson, O.J.; Krimsky, M; Lieberman, L.; Allen, P.; Vytal, K.; Grillon, C.

    2014-01-01

    We have delineated, across four prior studies, the role of positive dorsal medial prefrontal/anterior cingulate cortex (dmPFC/ACC)-amygdala circuit coupling during aversive processing in healthy individuals under stress. This translational circuit, termed the 'aversive amplification circuit', is thought to drive adaptive, harm-avoidant behavior in threatening environments. Here, in a natural progression of this prior work, we confirm that this circuit also plays a role in the pathological man...

  17. Do evolutionary perspectives of morning sickness and meat aversions apply to large-scale societies? : an examination of medieval Christian women

    OpenAIRE

    Snodgrass, Kristen M.

    2012-01-01

    A hypothesis put forth in 2002 by Daniel Fessler argues that, of all food types, meat and animal products are the most likely food items to carry pathogens and are, therefore, the principle target of gestational food aversions and pregnancy food taboos. Fessler posits these aversions are likely a source of selective pressure that has affected pregnant females throughout human history. Through an examination of 73 societies, Fessler's findings support his hypothesis. These societies, however, ...

  18. Risk aversion and institutional information disclosure on the European carbon market: A case-study of the 2006 compliance event

    International Nuclear Information System (INIS)

    This article evaluates the impact of the 2006 compliance event on changes in investors' risk aversion on the European carbon market using the newly available option prices dataset. Thus, we aim at capturing the specific event that occurred on April 2007 as the European Commission disclosed the 2006 verified emissions data. Following the methodology existing for stock indices, we recover empirically risk aversion adjustments on the period 2006-2007 by estimating first the risk-neutral distribution from option prices and second the actual distribution from futures on the European Climate Exchange. Our results show evidence of a dramatic change in the market perception of risk around the 2006 yearly compliance event that has not been assessed yet

  19. Risk aversion and institutional information disclosure on the European carbon market. A case-study of the 2006 compliance event

    Energy Technology Data Exchange (ETDEWEB)

    Chevallier, Julien [Grantham Institute for Climate Change, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); EconomiX-CNRS, University of Paris 10 (France); Ielpo, Florian [Pictet Asset Management, Route des Acacias 60, CH-1211 Geneva 73 and CES-CNRS, University of Paris 1 (France); Mercier, Ludovic [Dexia Credit Local, Paris (France)

    2009-01-15

    This article evaluates the impact of the 2006 compliance event on changes in investors' risk aversion on the European carbon market using the newly available option prices dataset. Thus, we aim at capturing the specific event that occurred on April 2007 as the European Commission disclosed the 2006 verified emissions data. Following the methodology existing for stock indices, we recover empirically risk aversion adjustments on the period 2006-2007 by estimating first the risk-neutral distribution from option prices and second the actual distribution from futures on the European Climate Exchange. Our results show evidence of a dramatic change in the market perception of risk around the 2006 yearly compliance event that has not been assessed yet. (author)

  20. Risk aversion and institutional information disclosure on the European carbon market: A case-study of the 2006 compliance event

    Energy Technology Data Exchange (ETDEWEB)

    Chevallier, Julien [Grantham Institute for Climate Change, Imperial College London, South Kensington Campus, London SW7 2AZ, UK and EconomiX-CNRS, University of Paris 10 (France)], E-mail: jchevall@u-paris10.fr; Ielpo, Florian [Pictet Asset Management, Route des Acacias 60, CH-1211 Geneva 73 and CES-CNRS, University of Paris 1 (France)], E-mail: ielpo@ces.ens-cachan.fr; Mercier, Ludovic [Dexia Credit Local, Paris (France)], E-mail: ludovic.mercier@clf-dexia.com

    2009-01-15

    This article evaluates the impact of the 2006 compliance event on changes in investors' risk aversion on the European carbon market using the newly available option prices dataset. Thus, we aim at capturing the specific event that occurred on April 2007 as the European Commission disclosed the 2006 verified emissions data. Following the methodology existing for stock indices, we recover empirically risk aversion adjustments on the period 2006-2007 by estimating first the risk-neutral distribution from option prices and second the actual distribution from futures on the European Climate Exchange. Our results show evidence of a dramatic change in the market perception of risk around the 2006 yearly compliance event that has not been assessed yet.

  1. Risk-averse decision-making for civil infrastructure exposed to low-probability, high-consequence events

    International Nuclear Information System (INIS)

    Quantitative analysis and assessment of risk to civil infrastructure has two components: probability of a potentially damaging event and consequence of damage, measured in terms of financial or human losses. Decision models that have been utilized during the past three decades take into account the probabilistic component rationally, but address decision-maker attitudes toward consequences and risk only to a limited degree. The application of models reflecting these attitudes to decisions involving low-probability, high-consequence events that may impact civil infrastructure requires a fundamental understanding of risk acceptance attitudes and how they affect individual and group choices. In particular, the phenomenon of risk aversion may be a significant factor in decisions for civil infrastructure exposed to low-probability events with severe consequences, such as earthquakes, hurricanes or floods. This paper utilizes cumulative prospect theory to investigate the role and characteristics of risk-aversion in assurance of structural safety.

  2. Aversive Peer Experiences on Social Networking Sites: Development of the Social Networking-Peer Experiences Questionnaire (SN-PEQ).

    Science.gov (United States)

    Landoll, Ryan R; La Greca, Annette M; Lai, Betty S

    2013-12-01

    Cyber victimization is an important research area; yet, little is known about aversive peer experiences on social networking sites (SNSs), which are used extensively by youth and host complex social exchanges. Across samples of adolescents (n=216) and young adults (n=214), we developed the Social Networking-Peer Experiences Questionnaire (SN-PEQ), and examined its psychometric properties, distinctiveness from traditional peer victimization, and associations with internalized distress. The SN-PEQ demonstrated strong factorial invariance and a single factor structure that was distinct from other forms of peer victimization. Negative SNS experiences were associated with youths' symptoms of social anxiety and depression, even when controlling for traditional peer victimization. Findings highlight the importance of examining the effects of aversive peer experiences that occur via social media. PMID:24288449

  3. The Controversy Around Tomboy: the Aversion to Gender Theory in French Education and Culture

    Directory of Open Access Journals (Sweden)

    Jennifer Vilchez

    2015-10-01

    Full Text Available By analyzing the controversy around Céline Sciamma’s Tomboy (2011 and the concept of gender theory, this paper discusses a demonstration of various levels of aversion to gender theory in current French political discourses as represented in the media in relation to same-sex marriage, the family and state education. The social institution of the family—whose functions encompass marriage and the rearing of children—is often considered a foundational unit of the state and civil society. After the family, the institution of education continues lessons of belonging, history, culture and nationality. In France, Sciamma’s Tomboy repeatedly appeared in public debates related to gender theory, primary education and the family. In early 2014, parents received mobile text messages to participate in a collective action to keep their children out of school to protest curriculum which would allegedly teach gender theory and include Tomboy as part of the Ecole et Cinéma educational program. Former Minister of Education Vincent Peillon responded to this campaign by stating that the national school system is in no way teaching “gender theory”. This film is approached as a polemical and subversive work in which gender is represented and perceived as a construct and performative identity, challenging traditional institutions of gender logics and the institution of the family, and as a learning tool to discuss gender differences and questions of equality in school. Both Tomboy and gender theory are represented in manners that do not engage with either topics directly but instead push forward specific agendas of various political groups such as protection of family and programs of equality. This sense of aversion towards gender theory and works like Tomboy are a reaction to anxieties towards changing French national identity. Tomboy finds itself within these tensions in current French national identity through its representation of children, gender and

  4. Variation in the Williams syndrome GTF2I gene and anxiety proneness interactively affect prefrontal cortical response to aversive stimuli.

    Science.gov (United States)

    Jabbi, M; Chen, Q; Turner, N; Kohn, P; White, M; Kippenhan, J S; Dickinson, D; Kolachana, B; Mattay, V; Weinberger, D R; Berman, K F

    2015-01-01

    Characterizing the molecular mechanisms underlying the heritability of complex behavioral traits such as human anxiety remains a challenging endeavor for behavioral neuroscience. Copy-number variation (CNV) in the general transcription factor gene, GTF2I, located in the 7q11.23 chromosomal region that is hemideleted in Williams syndrome and duplicated in the 7q11.23 duplication syndrome (Dup7), is associated with gene-dose-dependent anxiety in mouse models and in both Williams syndrome and Dup7. Because of this recent preclinical and clinical identification of a genetic influence on anxiety, we examined whether sequence variation in GTF2I, specifically the single-nucleotide polymorphism rs2527367, interacts with trait and state anxiety to collectively impact neural response to anxiety-laden social stimuli. Two hundred and sixty healthy adults completed the Tridimensional Personality Questionnaire Harm Avoidance (HA) subscale, a trait measure of anxiety proneness, and underwent functional magnetic resonance imaging (fMRI) while matching aversive (fearful or angry) facial identity. We found an interaction between GTF2I allelic variations and HA that affects brain response: in individuals homozygous for the major allele, there was no correlation between HA and whole-brain response to aversive cues, whereas in heterozygotes and individuals homozygous for the minor allele, there was a positive correlation between HA sub-scores and a selective dorsolateral prefrontal cortex (DLPFC) responsivity during the processing of aversive stimuli. These results demonstrate that sequence variation in the GTF2I gene influences the relationship between trait anxiety and brain response to aversive social cues in healthy individuals, supporting a role for this neurogenetic mechanism in anxiety. PMID:26285132

  5. Loss aversion and price volatility as determinants of attitude towards and preference for variable price in the Swedish electricity market

    Energy Technology Data Exchange (ETDEWEB)

    Juliusson, E. Asgeir; Gamble, Amelie; Gaerling, Tommy [Goeteborg University, Goeteborg (Sweden). Department of Psychology

    2007-11-15

    The results of a survey of a random sample of 488 Swedish residents showed that a positive attitude towards and preference for a variable price agreement with the incumbent electricity supplier was negatively affected by loss aversion, and a positive attitude also negatively affected by beliefs about price volatility. Although correlated with attitude and preference, age, education, and current choice of a variable price agreement had no independent effects. Income and current electricity costs had no effects. (author)

  6. Cooperative game analysis of a supply chain with one risk-neutral supplier and two risk-averse retailers

    OpenAIRE

    Changwen Li; Yongwu Zhou; Yong Lu; Jinsen Guo

    2014-01-01

    Purpose: This paper considers a two-echelon supply chain composed of one risk-neutral supplier and two risk-averse retailers. The retailers obtain production from the supplier and sell them to the market. Based on the cooperative game theory, the paper studies the appropriate profit allocation of the supply chain when all the players cooperate with each other, where the two retailers face a price-sensitive stochastic demand. The two retailers can either determine their retail prices independe...

  7. Cooperative game analysis of a supply chain with one risk-neutral supplier and two risk-averse retailers

    Directory of Open Access Journals (Sweden)

    Changwen Li

    2014-09-01

    Full Text Available Purpose: This paper considers a two-echelon supply chain composed of one risk-neutral supplier and two risk-averse retailers. The retailers obtain production from the supplier and sell them to the market. Based on the cooperative game theory, the paper studies the appropriate profit allocation of the supply chain when all the players cooperate with each other, where the two retailers face a price-sensitive stochastic demand. The two retailers can either determine their retail prices independently, or decide whether or not to cooperate with each other. Design/methodology/approach: To allocate the system-wide profit among upstream risk-neutral suppliers and two risk-averse downstream retailers, this paper constructed a cooperative game model, considered as the supermodularity of the characteristic function and the Shapley value of the game. Findings and Originality/value: By analyzing the construction’s cooperative game model, the results show that the profit of the whole supply chain is the highest in the grand coalition structure. This paper also shows that the core of our cooperative game is nonempty, and has the supermodularity property. Based on this, we have computed the Shapley value-based profit allocation for the whole supply chain in a fair manner. Originality/value: Although there are a lot of literature examined risk aversion in a supply chain, but they did not consider using cooperative game to study this problem. This the first study is in the context of a supply chain with risk aversion problem.

  8. Acquisition of conditioned taste aversion is impaired in the APP/PS1 mouse model of Alzheimer’s disease

    OpenAIRE

    Pistell, Paul J.; Zhu, Min; Ingram, Donald K.

    2008-01-01

    Research into the underlying mechanisms of cognitive dysfunction in Alzheimer’s disease (AD) has relied traditionally on tasks such as the water maze which evaluate spatial learning and memory. Since non-spatial forms of memory are also disrupted by AD, it is critical to establish other paradigms capable of investigating these deficits. Utilizing a non-spatial learning task, acquisition of conditioned taste aversion (CTA) was evaluated in a mouse model of AD. This line of transgenic mice enco...

  9. Relative Risk Aversion and Social Reproduction in Intergenerational Educational Attainment: Application of a Dynamic Discrete Choice Mode

    OpenAIRE

    Anders Holm; Mads Meier Jæger

    2005-01-01

    The theory of Relative Risk Aversion (RRA) claims that educational decision-making is ultimately motivated by the individual’s desire to avoid downward social class mobility, and that this desire is stronger than the desire to pursue upward mobility. This paper implements a dynamic programming model which tests the central behavioral assumption in the RRA theory stating that (1) individuals are forward-looking when choosing education and (2) that the RRA mechanism comprises an important compo...

  10. Influences of β-endorphins in Ethanol Consumption Patterns and Acquisition of a Conditioned Taste Aversion Mediated by the Drug

    Directory of Open Access Journals (Sweden)

    Juan Carlos Molina

    2009-09-01

    Full Text Available Rewarding effects of ethanol may be mediated in part by endogenous opioids. Ethanol alters β-endorphin synthesis and release. β-endorphin heterozygous (HT and knockout (KO mice consume higher levels of a low-concentrated alcohol solution and show heightened predisposition to self-administer ethanol in comparison with wild-type (WT mice (Grisel et al., 1999. This study was conducted in order to: i re-analyze and extend previous results in terms of ethanol consumption profiles of β-endorphin deficient mice; and ii analyze conditioned aversive learning mediated by ethanol postabsorptive effects as a function of genetic capabilities to synthesize β-endorphin. In Experiment 1, mice were evaluated in terms of consumption of a low (7% ethanol solution in a two-bottle free choice paradigm. Ethanol concentration was then increased to 10 % and voluntary intake consumption was tested. WT mice displayed significantly higher consumption levels and ethanol-preference scores than did KO mice, independently from ethanol concentration. HT mice drank more ethanol than did KO mice. In Experiment 2, mice (KO, HT and WT were tested in a conditioned taste aversion paradigm in which a sodium chloride (NaCl solution was paired with a 2-g/kg ethanol dose. Only HT and KO displayed a conditioned aversion when using 2-g/kg ethanol as unconditioned stimulus. The present results indicate that total or partial deficiency of β-endorphin synthesis reduces ethanol preference and consumption. Furthermore, this study indicates that the lack of β-endorphin synthesis exacerbates ethanol’s aversive postabsorptive effects which can in turn modulate self-administration patterns of the drug.

  11. Aversive Peer Experiences on Social Networking Sites: Development of the Social Networking-Peer Experiences Questionnaire (SN-PEQ)

    OpenAIRE

    Landoll, Ryan R.; La Greca, Annette M.; Lai, Betty S.

    2013-01-01

    Cyber victimization is an important research area; yet, little is known about aversive peer experiences on social networking sites (SNSs), which are used extensively by youth and host complex social exchanges. Across samples of adolescents (n=216) and young adults (n=214), we developed the Social Networking-Peer Experiences Questionnaire (SN-PEQ), and examined its psychometric properties, distinctiveness from traditional peer victimization, and associations with internalized distress. The SN-...

  12. The monetary value of the man-mSv for Korean NPP radiation workers assessed by the radiation aversion factor.

    Science.gov (United States)

    Lee, Byoung-il; Suh, Dong-hee; Kim, So-i; Jeong, Mi-seon; Lim, Young-khi

    2012-07-01

    The monetary value of the man-mSv for operators of Korean nuclear power plants (NPPs) was calculated using a radiation aversion factor based on a survey of NPP workers. Initially, the life expectancy in the population is 79.4 y, the average age of cancer occurrence is 60 y, the average annual wage for an electric worker is 56 000 $ y(-1) and the nominal risk coefficient induced by radiation is 4.2E(-5) mSv were used to evaluate the basic monetary value (α(base)) resulting in 45.6 $ mSv(-1). To investigate the degree of radiation aversion, the subject of the investigation was selected as the working radiation workers in 10 NPPs in Korea (Kori 1-2, Yeonggwang 1-3, Ulchin 1-3 and Wolseong 1-2). In August 2010, with the cooperation of KHNP and partner companies, a total of 2500 survey questionnaires to 10 NPPs (or 250 surveys to each NPP) were distributed to currently employed radiation workers. From these, 2157 responses were obtained between August and October 2010. The assessed radiation aversion factor and the monetary value of the man-mSv from the calculated radiation aversion factor were 1.26 and ∼50 $ in the 0-1 mSv range, 1.38 and ∼200 $ in the 1-5 mSv range, 1.52 and ∼1000 $ in the 5-10 mSv range, 1.65 and ∼4000 $ in the 10-20 mSv range and 1.74 and ∼8500 $ >20 mSv. PMID:22147927

  13. The monetary value of the man-mSv for Korean NPP radiation workers assessed by the radiation aversion factor

    International Nuclear Information System (INIS)

    The monetary value of the man-mSv for operators of Korean nuclear power plants (NPPs) was calculated using a radiation aversion factor based on a survey of NPP workers. Initially, the life expectancy in the population is 79.4 y, the average age of cancer occurrence is 60 y, the average annual wage for an electric worker is 56 000 $ y-1 and the nominal risk coefficient induced by radiation is 4.2 E-5 mSv were used to evaluate the basic monetary value (α base) resulting in 45.6 $ mSv-1. To investigate the degree of radiation aversion, the subject of the investigation was selected as the working radiation workers in 10 NPPs in Korea (Kori 1-2, Yeonggwang 1-3, Ulchin 1-3 and Wolseong 1-2). In August 2010, with the cooperation of KHNP and partner companies, a total of 2500 survey questionnaires to 10 NPPs (or 250 surveys to each NPP) were distributed to currently employed radiation workers. From these, 2157 responses were obtained between August and October 2010. The assessed radiation aversion factor and the monetary value of the man-mSv from the calculated radiation aversion factor were 1.26 and ∼50 $ in the 0-1 mSv range, 1.38 and ∼200 $ in the 1-5 mSv range, 1.52 and ∼1000 $ in the 5-10 mSv range, 1.65 and ∼4000 $ in the 10-20 mSv range and 1.74 and ∼8500 $ >20 mSv. (authors)

  14. Investigating Methods to Reduce Black Bear (Ursus americanus) Visitation to Anthropogenic Food Sources: Conditioned Taste Aversion and Food Removal

    OpenAIRE

    Signor, Kari D.

    2009-01-01

    Conflicts between humans and black bears (Ursus americanus) jeopardize the safety of both humans and bears, especially when bears become food-conditioned to anthropogenic food sources in areas such as campgrounds. Interest in using non-lethal techniques, such as aversive conditioning, to manage such conflicts is growing. I conducted a captive experiment at The Wildlife Science Center in Minnesota and two field experiments in the La Sal Mountains, Utah, to investigate the effects of taste av...

  15. Earthquake Risk Information and Risk Aversive Behavior: Evidence from a Survey of Residents in Tokyo Metropolitan Area

    OpenAIRE

    Yasuo Kawawaki

    2012-01-01

    This paper analyzes the relationship between provision of earthquake risk information and residents' willingness to pay (WTP) for disaster risk reduction by the Contingent Valuation Method (CVM), using questionnaire survey data on the purchase of earthquake insurance in the Tokyo Metropolitan Area, Japan. Degree of disaster risk aversion and subjective probability of loss are estimated as parameters of expected utility function in a discrete choice model. The results suggest that when more pr...

  16. Dopamine Receptor Blockade Modulates the Rewarding and Aversive Properties of Nicotine via Dissociable Neuronal Activity Patterns in the Nucleus Accumbens

    OpenAIRE

    Sun, Ninglei; Laviolette, Steven R

    2014-01-01

    The mesolimbic pathway comprising the ventral tegmental area (VTA) and projection terminals in the nucleus accumbens (NAc) has been identified as a critical neural system involved in processing both the rewarding and aversive behavioral effects of nicotine. Transmission through dopamine (DA) receptors functionally modulates these effects directly within the NAc. Nevertheless, the neuronal mechanisms within the NAc responsible for these bivalent behavioral effects are presently not known. Usin...

  17. The role of dopamine in the context of aversive stimuli with particular reference to acoustically signaled avoidance learning

    Directory of Open Access Journals (Sweden)

    Anton eIlango

    2012-09-01

    Full Text Available Learning from punishment is a powerful means for behavioral adaptation with high relevance for various mechanisms of self-protection. Several studies have explored the contribution of released dopamine (DA or responses of DA neurons on reward seeking using rewards such as food, water, and sex. Phasic DA signals evoked by rewards or conditioned reward predictors are well documented, as are modulations of these signals by such parameters as reward magnitude, probability, and deviation of actually occurring from expected rewards. Less attention has been paid to DA neuron firing and DA release in response to aversive stimuli, and the prediction and avoidance of punishment. In this review, we first focus on DA changes in response to aversive stimuli as measured by microdialysis and voltammetry followed by the change in electrophysiological signatures by aversive stimuli and fearful events. We subsequently focus on the role of DA and effect of DA manipulations on signaled avoidance learning, which consists of learning the significance of a warning cue through Pavlovian associations and the execution of an instrumental avoidance response. We present a coherent framework utilizing the data on microdialysis, voltammetry, electrophysiological recording, electrical brain stimulation and behavioral analysis. We end by outlining current gaps in the literature and proposing future directions aimed at incorporating technical and conceptual progress to understand the involvement of reward circuit on punishment based decisions.

  18. Differential involvement of glutamatergic and catecholaminergic activity within the amygdala during taste aversion retrieval on memory expression and updating.

    Science.gov (United States)

    Daniel, Osorio-Gómez; Kioko, Guzmán-Ramos; Federico, Bermúdez-Rattoni

    2016-07-01

    During memory retrieval, consolidated memories are expressed and destabilized in order to maintain or update information through a memory reconsolidation process. Despite the key role of the amygdala during memory acquistion and consolidation, the participation of neurotransmitter signals in memory retrieval is poorly understood. Hence, we used conditioned taste aversion and in vivo microdialysis to evaluate changes in glutamate, norepinephrine and dopamine concentrations within the amygdala during memory retrieval. We observed that exposure to an aversive-conditioned stimulus induced an augmentation in glutamate, norepinephrine and dopamine levels within the amygdala, while exposure to a familiar and safe stimulus did not induce changes in these neurotransmitters levels. Also, we evaluated the amygdalar blockade of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-d-aspartate (NMDA), β-adrenergic and dopamine D1 receptors in memory retrieval and updating. Results showed that during retrieval, behavioural expression was impaired by intra-amygdalar blockade of AMPA and β-adrenergic receptors, whereas NMDA, D1 and β-adrenergic receptors blockade hindered memory updating. In summary, during conditioned taste aversion retrieval there was an increase in the extracellular levels of glutamate, norepinephrine and dopamine within the amygdala, and their receptors activity were differentially involved in the behavioural expression and memory updating during retrieval. PMID:27018173

  19. Coordinating Contracts for Two-Stage Fashion Supply Chain with Risk-Averse Retailer and Price-Dependent Demand

    Directory of Open Access Journals (Sweden)

    Minli Xu

    2013-01-01

    Full Text Available When the demand is sensitive to retail price, revenue sharing contract and two-part tariff contract have been shown to be able to coordinate supply chains with risk neutral agents. We extend the previous studies to consider a risk-averse retailer in a two-echelon fashion supply chain. Based on the classic mean-variance approach in finance, the issue of channel coordination in a fashion supply chain with risk-averse retailer and price-dependent demand is investigated. We propose both single contracts and joint contracts to achieve supply chain coordination. We find that the coordinating revenue sharing contract and two-part tariff contract in the supply chain with risk neutral agents are still useful to coordinate the supply chain taking into account the degree of risk aversion of fashion retailer, whereas a more complex sales rebate and penalty (SRP contract fails to do so. When using combined contracts to coordinate the supply chain, we demonstrate that only revenue sharing with two-part tariff contract can coordinate the fashion supply chain. The optimal conditions for contract parameters to achieve channel coordination are determined. Numerical analysis is presented to supplement the results and more insights are gained.

  20. Effects of exogenous cholecystokinin octapeptide on acquisition of naloxone precipitated withdrawal induced conditioned place aversion in rats.

    Directory of Open Access Journals (Sweden)

    Hailei Yu

    Full Text Available Cholecystokinin octapeptide (CCK-8, a gut-brain peptide, regulates a variety of physiological behavioral processes. Previously, we reported that exogenous CCK-8 attenuated morphine-induced conditioned place preference, but the possible effects of CCK-8 on aversively motivated drug seeking remained unclear. To investigate the effects of endogenous and exogenous CCK on negative components of morphine withdrawal, we evaluated the effects of CCK receptor antagonists and CCK-8 on the naloxone-precipitated withdrawal-induced conditioned place aversion (CPA. The results showed that CCK2 receptor antagonist (LY-288,513, 10 µg, i.c.v., but not CCK1 receptor antagonist (L-364,718, 10 µg, i.c.v., inhibited the acquisition of CPA when given prior to naloxone (0.3 mg/kg administration in morphine-dependent rats. Similarly, CCK-8 (0.1-1 µg, i.c.v. significantly attenuated naloxone-precipitated withdrawal-induced CPA, and this inhibitory function was blocked by co-injection with L-364,718. Microinjection of L-364,718, LY-288,513 or CCK-8 to saline pretreated rats produced neither a conditioned preference nor aversion, and the induction of CPA by CCK-8 itself after morphine pretreatments was not significant. Our study identifies a different role of CCK1 and CCK2 receptors in negative affective components of morphine abstinence and an inhibitory effect of exogenous CCK-8 on naloxone-precipitated withdrawal-induced CPA via CCK1 receptor.

  1. Aversive and non-reward learning in the fire-bellied toad using familiar and unfamiliar prey stimuli

    Directory of Open Access Journals (Sweden)

    Ursula DICKE, Antje HEIDORN, Gerhard ROTH

    2011-12-01

    Full Text Available The present study investigated how snapping behavior toward familiar and unfamiliar prey is modified by reward omission and aversive conditioning in the fire-bellied toad Bombina orientalis. Toads were trained to snap at cricket images by rewarding them with live crickets. The task was learned, and the learning criterion (10 snapping responses within 2 minutes was reached in all individuals investigated. Subsequent reward omission did not alter the frequency of snapping to the familiar cricket stimulus. Snapping decreased only in some individuals, when a mild foot shock was applied at snapping. However, at presentation of images of hitherto unfamiliar meal worms and foot-shock application at snapping to the stimulus, the majority of toads diminished snapping significantly. Snapping responses decreased more rapidly, when snapping at meal worms was not rewarded or a footshock was applied uncorrelated to the presentation of or snapping at meal worms. These results demonstrate that in toads familiarity and unfamiliarity of prey stimuli are important factors in aversive learning, because well-trained responses to familiar stimuli become immune against reward omission. Furthermore, at presentation of unfamiliar stimuli, omission of reward and uncorrelated footshock had a stronger aversive effect than correlated footshock [Current Zoology 57 (6: 709–716, 2011].

  2. Aversive and non-reward learning in the fire-bellied toad using familiar and unfamiliar prey stimuli

    Institute of Scientific and Technical Information of China (English)

    Ursula DICKE; Antje HEIDORN; Gerhard ROTH

    2011-01-01

    The present study investigated how snapping behavior toward familiar and unfamiliar prey is modified by reward omission and aversive conditioning in the fure-bellied toad Bombina orientalis.Toads were trained to snap at cricket images by rewarding them with live crickets.The task was learned,and the learning criterion (10 snapping responses within 2 minutes) was reached in all individuals investigated.Subsequent reward omission did not alter the frequency of snapping to the familiar cricket stimulus.Snapping decreased only in some individuals,when a mild foot shock was applied at snapping.However,at presentation of images of hitherto unfamiliar meal worms and foot-shock application at snapping to the stimulus,the majority of toads diminished snapping significantly.Snapping responses decreased more rapidly,when snapping at meal worms was not rewarded or a footshock was applied uncorrelated to the presentation of or snapping at meal worms.These results demonstrate that in toads familiarity and unfamiliarity of prey stimuli are important factors in aversive learning,because well-trained responses to familiar stimuli become immune against reward omission.Furthermore,at presentation of unfamiliar stimuli,omission of reward and uncorrelated footshock had a stronger aversive effect than correlated footshock [Current Zoology 57 (6):709-716,2011 ].

  3. Development of an inexact risk-aversion optimization model for regional carbon constrained electricity system planning under uncertainty

    International Nuclear Information System (INIS)

    Highlights: • Inexact two-stage stochastic risk-aversion programming model for electric system planning. • CO2 emission cap and trade scheme were considered. • Generation expansion and operation schedule were provided. • Investment, and operation cost were analyzed with the decision makers’ risk preference. • Uncertainties were expressed as discrete intervals with associated probability distributions. - Abstract: Since carbon dioxide (CO2) emission reduction gains global concerns, power industry is one of the main sources of CO2 emission. Thus, carbon cap and trade scheme and the application of carbon capture and storage have been employed to mitigate CO2 emission. In consideration of these technologies and constraints, an inexact risk-aversion model based on interval two-stage stochastic programming (ITSP) and conditional value at risk method (CVaR) for multi-period electric system planning problem was developed in this study. Under the optimization framework, more realistic problems such as the demand growth, technology development and environmental policy changes were taken into consideration. CVaR was employed as a risk aversion criterion to reflect the decision maker’s risk preference. A case study for regional electric system planning was demonstrated to verify the capabilities of this optimal approach. The series results provided decision makers with trade-off between the expected system cost and CVaR. It provided valuable insights to make informed long term electric system planning decisions with respect to CCS technology and political and market uncertainties

  4. A Bibliometric Analysis of Research on the Behavior Therapy in China and Its Trend

    Institute of Scientific and Technical Information of China (English)

    赵山明; 能昌华; 吴汉荣

    2003-01-01

    To get formed of the status of research and application of the domestic behavior therapy and its development trend, the time distribution and the subject distribution were bibliometricallly analyzed of the literature on behavior therapy from 1981 to 2000 in the CBMdisc. Our results showed that the number of literature of behavior therapy has been increasing in exponential manner over the past 20 years; the behavior modification, the biofeedback and the cognitive therapy are extensively used in China. In clinical practice, the behavior modification and the biofeedback have been applied in all departments of medical institutions, especially for treating the cardiovascular and the neurological conditions. The cognitive therapy has been employed mainly for the treatment of mental disorders (or dysphrenia), the aversive therapy mainly for material withdrawal, and the systematic desensitization for phobia. There was no report found on the clinical use of meditation. It is concluded that the study and application in behavior therapy in China is currently developing very fast.

  5. Response threshold to aversive stimuli in stimulated early protein-malnourished rats

    Directory of Open Access Journals (Sweden)

    L.F. Rocinholi

    1997-03-01

    Full Text Available Two animal models of pain were used to study the effects of short-term protein malnutrition and environmental stimulation on the response threshold to aversive stimuli. Eighty male Wistar rats were used. Half of the pups were submitted to malnutrition by feeding their mothers a 6% protein diet from 0 to 21 days of age while the mothers of the other half (controls were well nourished, receiving 16% protein. From 22 to 70 days all rats were fed commercial lab chow. Half of the animals in the malnourished and control groups were maintained under stimulating conditions, including a 3-min daily handling from 0 to 70 days and an enriched living cage after weaning. The other half was reared in a standard living cage. At 70 days, independent groups of rats were exposed to the shock threshold or to the tail-flick test. The results showed lower body and brain weights in malnourished rats when compared with controls at weaning and testing. In the shock threshold test the malnourished animals were more sensitive to electric shock and environmental stimulation increased the shock threshold. No differences due to diet or environmental stimulation were found in the tail-flick procedure. These results demonstrate that protein malnutrition imposed only during the lactation period is efficient in inducing hyperreactivity to electric shock and that environmental stimulation attenuates the differences in shock threshold produced by protein malnutrition

  6. An aromatic sensor with aversion to damaged strands confers versatility to DNA repair.

    Directory of Open Access Journals (Sweden)

    Olivier Maillard

    2007-04-01

    Full Text Available It was not known how xeroderma pigmentosum group C (XPC protein, the primary initiator of global nucleotide excision repair, achieves its outstanding substrate versatility. Here, we analyzed the molecular pathology of a unique Trp690Ser substitution, which is the only reported missense mutation in xeroderma patients mapping to the evolutionary conserved region of XPC protein. The function of this critical residue and neighboring conserved aromatics was tested by site-directed mutagenesis followed by screening for excision activity and DNA binding. This comparison demonstrated that Trp690 and Phe733 drive the preferential recruitment of XPC protein to repair substrates by mediating an exquisite affinity for single-stranded sites. Such a dual deployment of aromatic side chains is the distinctive feature of functional oligonucleotide/oligosaccharide-binding folds and, indeed, sequence homologies with replication protein A and breast cancer susceptibility 2 protein indicate that XPC displays a monomeric variant of this recurrent interaction motif. An aversion to associate with damaged oligonucleotides implies that XPC protein avoids direct contacts with base adducts. These results reveal for the first time, to our knowledge, an entirely inverted mechanism of substrate recognition that relies on the detection of single-stranded configurations in the undamaged complementary sequence of the double helix.

  7. Environmental Resource Management in Borderlands: Evolution from Competing Interests to Common Aversions

    Directory of Open Access Journals (Sweden)

    Patrick Henry Buckley

    2015-07-01

    Full Text Available Great enthusiasm is attached to the emergence of cross-border regions (CBRs as a new institutional arrangement for dealing with local cross-border environmental resource management and other issues that remain too distant from national capitals and/or too expensive to be addressed in the traditional topocratic manner requiring instead local adhocratic methods. This study briefly discusses the perceived value of CBRs and necessary and sufficient conditions for the successful and sustainable development of such places. Then, assuming that necessary conditions can be met, the study investigates an intriguing hypothesis concerning the catalyzing of sustainable consensus for cross-border resource management based on a game theoretical approach that employs the use of dilemma of common aversion rather than the more traditional dilemma of competing common interests. Using this lens to investigate a series of events on the Pacific northwestern Canadian-American border in a part of the Fraser Lowland, we look for evidence of the emergence of an active and sustainable CBR to address local trans-border resource management issues. Although our micro-level scale fails to conclusively demonstrate such evidence, it does demonstrate the value of using this approach and suggests a number of avenues for further research.

  8. fMRI neurofeedback of amygdala response to aversive stimuli enhances prefrontal-limbic brain connectivity.

    Science.gov (United States)

    Paret, Christian; Ruf, Matthias; Gerchen, Martin Fungisai; Kluetsch, Rosemarie; Demirakca, Traute; Jungkunz, Martin; Bertsch, Katja; Schmahl, Christian; Ende, Gabriele

    2016-01-15

    Down-regulation of the amygdala with real-time fMRI neurofeedback (rtfMRI NF) potentially allows targeting brain circuits of emotion processing and may involve prefrontal-limbic networks underlying effective emotion regulation. Little research has been dedicated to the effect of rtfMRI NF on the functional connectivity of the amygdala and connectivity patterns in amygdala down-regulation with neurofeedback have not been addressed yet. Using psychophysiological interaction analysis of fMRI data, we present evidence that voluntary amygdala down-regulation by rtfMRI NF while viewing aversive pictures was associated with increased connectivity of the right amygdala with the ventromedial prefrontal cortex (vmPFC) in healthy subjects (N=16). In contrast, a control group (N=16) receiving sham feedback did not alter amygdala connectivity (Group×Condition t-contrast: pneurofeedback to influence functional connectivity in key networks of emotion processing and regulation. This may be beneficial for patients suffering from severe emotion dysregulation by improving neural self-regulation. PMID:26481674

  9. Configural integration of temporal and contextual information in rats: Automated measurement in appetitive and aversive preparations.

    Science.gov (United States)

    Dumigan, Natasha M; Lin, Tzu-Ching E; Good, Mark; Honey, Robert C

    2015-06-01

    Two experiments investigated the capacity of rats to learn configural discriminations requiring integration of contextual (where) with temporal (when) information. In Experiment 1, during morning training sessions, food was delivered in context A and not in context B, whereas during afternoon sessions food was delivered in context B and not in context A. Rats acquired this discrimination over the course of 20 days. Experiment 2 employed a directly analogous aversive conditioning procedure in which footshock served in place of food. This procedure allowed the acquisition of the discrimination to be assessed through changes in activity to the contextual + temporal configurations (i.e., inactivity or freezing) and modulation of the immediate impact of footshock presentations (i.e., post-shock activity bursts). Both measures provided evidence of configural learning over the course of 12 days, with a final test showing that the presentation of footshock resulted in more post-shock activity in the nonreinforced than reinforced configurations. These behavioral effects reveal important parallels between (i) configural discrimination learning involving components allied to episodic memory and (ii) simple conditioning. PMID:25762427

  10. A risk-averse optimization model for trading wind energy in a market environment under uncertainty

    International Nuclear Information System (INIS)

    In this paper, a stochastic programming approach is proposed for trading wind energy in a market environment under uncertainty. Uncertainty in the energy market prices is the main cause of high volatility of profits achieved by power producers. The volatile and intermittent nature of wind energy represents another source of uncertainty. Hence, each uncertain parameter is modeled by scenarios, where each scenario represents a plausible realization of the uncertain parameters with an associated occurrence probability. Also, an appropriate risk measurement is considered. The proposed approach is applied on a realistic case study, based on a wind farm in Portugal. Finally, conclusions are duly drawn. -- Highlights: → We model uncertainties on energy market prices and wind power production. → A hybrid intelligent approach generates price-wind power scenarios. → Risk aversion is also incorporated in the proposed stochastic programming approach. → A realistic case study, based on a wind farm in Portugal, is provided. → Our approach allows selecting the best solution according to the desired risk exposure level.

  11. Environmental Resource Management in Borderlands: Evolution from Competing Interests to Common Aversions

    Science.gov (United States)

    Buckley, Patrick Henry; Belec, John; Levy, Jason

    2015-01-01

    Great enthusiasm is attached to the emergence of cross-border regions (CBRs) as a new institutional arrangement for dealing with local cross-border environmental resource management and other issues that remain too distant from national capitals and/or too expensive to be addressed in the traditional topocratic manner requiring instead local adhocratic methods. This study briefly discusses the perceived value of CBRs and necessary and sufficient conditions for the successful and sustainable development of such places. Then, assuming that necessary conditions can be met, the study investigates an intriguing hypothesis concerning the catalyzing of sustainable consensus for cross-border resource management based on a game theoretical approach that employs the use of dilemma of common aversion rather than the more traditional dilemma of competing common interests. Using this lens to investigate a series of events on the Pacific northwestern Canadian-American border in a part of the Fraser Lowland, we look for evidence of the emergence of an active and sustainable CBR to address local trans-border resource management issues. Although our micro-level scale fails to conclusively demonstrate such evidence, it does demonstrate the value of using this approach and suggests a number of avenues for further research. PMID:26154660

  12. Two independent mushroom body output circuits retrieve the six discrete components of Drosophila aversive memory.

    Science.gov (United States)

    Bouzaiane, Emna; Trannoy, Séverine; Scheunemann, Lisa; Plaçais, Pierre-Yves; Preat, Thomas

    2015-05-26

    Understanding how the various memory components are encoded and how they interact to guide behavior requires knowledge of the underlying neural circuits. Currently, aversive olfactory memory in Drosophila is behaviorally subdivided into four discrete phases. Among these, short- and long-term memories rely, respectively, on the γ and α/β Kenyon cells (KCs), two distinct subsets of the ∼2,000 neurons in the mushroom body (MB). Whereas V2 efferent neurons retrieve memory from α/β KCs, the neurons that retrieve short-term memory are unknown. We identified a specific pair of MB efferent neurons, named M6, that retrieve memory from γ KCs. Moreover, our network analysis revealed that six discrete memory phases actually exist, three of which have been conflated in the past. At each time point, two distinct memory components separately recruit either V2 or M6 output pathways. Memory retrieval thus features a dramatic convergence from KCs to MB efferent neurons. PMID:25981036

  13. Two Independent Mushroom Body Output Circuits Retrieve the Six Discrete Components of Drosophila Aversive Memory

    Directory of Open Access Journals (Sweden)

    Emna Bouzaiane

    2015-05-01

    Full Text Available Understanding how the various memory components are encoded and how they interact to guide behavior requires knowledge of the underlying neural circuits. Currently, aversive olfactory memory in Drosophila is behaviorally subdivided into four discrete phases. Among these, short- and long-term memories rely, respectively, on the γ and α/β Kenyon cells (KCs, two distinct subsets of the ∼2,000 neurons in the mushroom body (MB. Whereas V2 efferent neurons retrieve memory from α/β KCs, the neurons that retrieve short-term memory are unknown. We identified a specific pair of MB efferent neurons, named M6, that retrieve memory from γ KCs. Moreover, our network analysis revealed that six discrete memory phases actually exist, three of which have been conflated in the past. At each time point, two distinct memory components separately recruit either V2 or M6 output pathways. Memory retrieval thus features a dramatic convergence from KCs to MB efferent neurons.

  14. Economic impacts of noxious facilities: Incorporating the effects of risk aversion

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.

    1993-09-01

    Developing new sites for noxious facilities has become a complex process with many potential pitfalls. In addition to the need to negotiate conditions acceptable to the host community, siting success may depend on the facility proposer`s ability to identify a candidate site that not only meets technical requirements, but that is located in a community or region whose population is not highly averse to the risks associated with the type of facility being proposed. Success may also depend on the proposer accurately assessing potential impacts of the facility and offering an equitable compensation package to the people affected by it. Facility impact assessments, as typically performed, include only the effects of changes in population, employment and economic activity associated with facility construction and operation. Because of their scope, such assessments usually show a short-run, net economic benefit for the host region, making the intensely negative public reaction to some types and locations of facilities seem unreasonable. The impact component excluded from these assessments is the long-run economic effect of public perceptions of facility risk and nuisance characteristics. Recent developments in psychological and economic measurement techniques have opened the possibility of correcting this flaw by incorporating public perceptions in projections of economic impacts from noxious facilities.

  15. Sleep Deprivation Alters Choice Strategy Without Altering Uncertainty or Loss Aversion Preferences

    Directory of Open Access Journals (Sweden)

    O'Dhaniel A Mullette-Gillman

    2015-10-01

    Full Text Available Sleep deprivation alters decision making; however, it is unclear what specific cognitive processes are modified to drive altered choices. In this manuscript, we examined how one night of total sleep deprivation (TSD alters economic decision making. We specifically examined changes in uncertainty preferences dissociably from changes in the strategy with which participants engage with presented choice information. With high test-retest reliability, we show that TSD does not alter uncertainty preferences or loss aversion. Rather, TSD alters the information the participants rely upon to make their choices. Utilizing a choice strategy metric which contrasts the influence of maximizing and satisficing information on choice behavior, we find that TSD alters the relative reliance on maximizing information and satisficing information, in the gains domain. This alteration is the result of participants both decreasing their reliance on cognitively-complex maximizing information and a concomitant increase in the use of readily-available satisficing information. TSD did not result in a decrease in overall information use in either domain. These results show that sleep deprivation alters decision making by altering the informational strategies that participants employ, without altering their preferences.

  16. Leptin receptor expression in the basolateral nucleus of amygdala of conditioned taste aversion rats

    Institute of Scientific and Technical Information of China (English)

    Zhen Han; Jian-Qun Yan; Guo-Gang Luo; Yong Liu; Yi-Li Wang

    2003-01-01

    AIM: To determine whether serum leptin level and the leptin receptor (OB-R) expression in the basolateral amygdala (BLA)change following conditioned taste aversion (CTA) formation.METHODS: The serum leptin concentration was measured by rat leptin RIA kit, long and short forms of leptin receptor (OB-Rb and OB-Ra) mRNA in the brain sections were examined by in situ hybridization (ISH) and the expression of OB-R was assessed by immunohistochemistry ABC method with a highly specific goat anti-OB-R antibody.RESULTS: The level of serum leptin didn't show significant difference between CTA and control group. Comparing with the control group, the CTA group had an increase on count of OB-R immunohistochemistry positive-stained cells in the BLA (127±12 vs 48±9 per 1 mm2). The OB-Rb mRNA expression level enhanced by 11.9 % in the BLA, while OBRa mRNA level increased by 7.4 % on the choroid plexus in CTA group. So BLA was supposed to be a region where interactions between gustatory and vagal signals take place.CONCLUSION: BLA is one of the sites, which are responsible for CTA formation in the brain. Leptin and OB-R maybe involved in neuronal communication for CTA. So leptin and its receptors probably take part in CTA and integration of autonomic and extroceptive information.

  17. Olfactory aversive conditioning alters olfactory bulb mitral/tufted cell glomerular odor responses

    Directory of Open Access Journals (Sweden)

    Max L Fletcher

    2012-03-01

    Full Text Available The anatomical organization of receptor neuron input into the olfactory bulb (OB allows odor information to be transformed into an odorant-specific spatial map of mitral/tufted cell glomerular activity at the upper level of the olfactory bulb. In other sensory systems, neuronal representations of stimuli can be reorganized or enhanced following learning. While the mammalian OB has been shown to undergo experience-dependent plasticity at the glomerular level, it is still unclear if similar representational change occurs within mitral/tufted cell glomerular odor representations following learning. To address this, odorant-evoked glomerular activity patterns were imaged in mice expressing a GFP-based calcium indicator (GCaMP2 in OB mitral/tufted cells. Glomerular odor responses were imaged before and after olfactory associative conditioning to aversive foot shock. Following conditioning, we found no overall reorganization of the glomerular representation. Training, however, did significantly alter the amplitudes of individual glomeruli within the representation in mice in which the odor was presented together with foot shock. Further, the specific pairing of foot shock with odor presentations lead to increased responses primarily in initially weakly activated glomeruli. Overall, these results suggest that associative conditioning can enhance the initial representation of odors within the olfactory bulb by enhancing responses to the learned odor in some glomeruli.

  18. Differential effects of wake promoting drug Modafinil in aversive learning paradigms

    Directory of Open Access Journals (Sweden)

    Bharanidharan eShanmugasundaram

    2015-08-01

    Full Text Available Modafinil (MO an inhibitor of the dopamine transporter was initially approved to treat narcolepsy, a sleep related disorder in humans. One interesting side-effect of this drug, which emerged from preclinical and clinical studies, is the facilitation of cognitive performance. So far, this was primarily shown in appetitive learning paradigms, but it is yet unclear whether MO exerts a more general cognitive enhancement effect. Thus, the aim of the present study in rats was to extend these findings by testing the effects of MO in two aversive paradigms, Pavlovian fear conditioning (FC and the operant two-way active avoidance (TWA learning paradigms. We discovered a differential, task-dependent effect of MO. In the FC paradigm MO treated rats showed a dose-dependent enhancement of fear memory compared to vehicle treated rats, indicated by increased context-related freezing. Cue related fear memory remained unaffected. In the TWA paradigm MO induced a slight, but significant decrease of avoidance responses compared to vehicle treated animals, while the number of escape reactions during the acquisition of the TWA task remained unaffected. These findings expand the knowledge in the regulation of cognitive abilities and may contribute to the understanding of the contraindicative effects of MO in anxiety related mental disorders.

  19. Aversive conditioning in honey bees (Apis mellifera anatolica): a comparison of drones and workers.

    Science.gov (United States)

    Dinges, Christopher W; Avalos, Arian; Abramson, Charles I; Craig, David Philip Arthur; Austin, Zoe M; Varnon, Christopher A; Dal, Fatima Nur; Giray, Tugrul; Wells, Harrington

    2013-11-01

    Honey bees provide a model system to elucidate the relationship between sociality and complex behaviors within the same species, as females (workers) are highly social and males (drones) are more solitary. We report on aversive learning studies in drone and worker honey bees (Apis mellifera anatolica) in escape, punishment and discriminative punishment situations. In all three experiments, a newly developed electric shock avoidance assay was used. The comparisons of expected and observed responses were performed with conventional statistical methods and a systematic randomization modeling approach called object oriented modeling. The escape experiment consisted of two measurements recorded in a master-yoked paradigm: frequency of response and latency to respond following administration of shock. Master individuals could terminate an unavoidable shock triggered by a decrementing 30 s timer by crossing the shuttlebox centerline following shock activation. Across all groups, there was large individual response variation. When assessing group response frequency and latency, master subjects performed better than yoked subjects for both workers and drones. In the punishment experiment, individuals were shocked upon entering the shock portion of a bilaterally wired shuttlebox. The shock portion was spatially static and unsignalled. Only workers effectively avoided the shock. The discriminative punishment experiment repeated the punishment experiment but included a counterbalanced blue and yellow background signal and the side of shock was manipulated. Drones correctly responded less than workers when shock was paired with blue. However, when shock was paired with yellow there was no observable difference between drones and workers. PMID:24133154

  20. The impact of perceived similarity on tacit coordination: propensity for matching and aversion to decoupling choices.

    Science.gov (United States)

    Chierchia, Gabriele; Coricelli, Giorgio

    2015-01-01

    Homophily, or "love for similar others," has been shown to play a fundamental role in the formation of interpersonal ties and social networks. Yet no study has investigated whether perceived similarities can affect tacit coordination. We had 68 participants attempt to maximize real monetary earnings by choosing between a safe but low paying option (that could be obtained with certainty) and a potentially higher paying but "risky" one, which depended on the choice of a matched counterpart. While making their choices participants were mutually informed of whether their counterparts similarly or dissimilarly identified with three person-descriptive words as themselves. We found that similarity increased the rate of "risky" choices only when the game required counterparts to match their choices (stag hunt games). Conversely, similarity led to decreased risk rates when they were to tacitly decouple their choices (entry games). Notably, though similarity increased coordination in the matching environment, it did not did not increase it in the decoupling game. In spite of this, similarity increased (expected) payoffs across both coordination environments. This could shed light on why homophily is so successful as a social attractor. Finally, this propensity for matching and aversion to decoupling choices was not observed when participants "liked" their counterparts but were dissimilar to them. We thus conclude that the impact of similarity of coordination should not be reduced to "liking" others (i.e., social preferences) but it is also about predicting them. PMID:26283940

  1. A qualitative study to discover the future scope and barriers towards facilitating animals-assisted therapy (AAT)for autisitic children in Macau (China)

    OpenAIRE

    Das Neves Chiang, Sara Violeta

    2015-01-01

    This qualitative study seeks to discover the future scope of developing animal-assisted therapy (AAT) in Macau (China) based on the local parents’ perspectives. Social aversion in children with autism tends to be human-specific thus does not take into account of therapy animals, which can offer calming and nonjudgmental support thus enhancing and encouraging social interactions in children with autism. The aims of this paper include evaluating current evidence on how AAT can support the domai...

  2. Role of the hippocampus in contextual memory after classical aversive conditioning in pigeons (C. livia

    Directory of Open Access Journals (Sweden)

    Reis F.

    1999-01-01

    Full Text Available We investigated the effects of hippocampal lesions with ibotenic acid (IBO on the memory of the sound-context-shock association during reexposure to the conditioning context. Twenty-nine adult pigeons were assigned to a non-lesioned control group (CG, N = 7, a sham-lesioned group (SG, N = 7, a hippocampus-lesioned experimental group (EG, N = 7, and to an unpaired nonlesioned group (tone-alone exposure (NG, N = 8. All pigeons were submitted to a 20-min session in the conditioning chamber with three associations of sound (1000 Hz, 85 dB, 1 s and shock (10 mA, 1 s. Experimental and sham lesions were performed 24 h later (EG and SG when EG birds received three bilateral injections (anteroposterior (A, 4.5, 5.25 and 7.0 of IBO (1 µl and 1 µg/µl and SG received one bilateral injection (A, 5.25 of PBS. The animals were reexposed to the training context 5 days after the lesion. Behavior was videotaped for 20 min and analyzed at 30-s intervals. A significantly higher percent rating of immobility was observed for CG (median, 95.1; range, 79.2 to 100.0 and SG (median, 90.0; range, 69.6 to 95.0 compared to EG (median, 11.62; range, 3.83 to 50.1 and NG (median, 7.33; range, 6.2 to 28.1 (P<0.001 in the training context. These results suggest impairment of contextual fear in birds who received lesions one day after conditioning and a role for the hippocampus in the modulation of emotional aversive memories in pigeons.

  3. Speed matters: relationship between speed of eye movements and modification of aversive autobiographical memories

    Directory of Open Access Journals (Sweden)

    Suzanne Chantal Van Veen

    2015-04-01

    Full Text Available Eye Movement Desensitization and Reprocessing (EMDR is an efficacious treatment for posttraumatic stress disorder. In EMDR, patients recall a distressing memory and simultaneously make eye movements (EM. Both tasks are considered to require limited working memory (WM resources. Because this leaves fewer resources available for memory retrieval, the memory should become less vivid and less emotional during future recall. Currently, EMDR is a standardized treatment and patients typically receive the same dual task manipulation of 1 EM cycle per second (1 Hz. From a WM perspective, the WM taxation of the dual task might be titrated to the WM taxation of the memory image. We hypothesized that highly vivid images are more affected by high WM taxation and less vivid images are more affected by low WM taxation. In study 1, 34 participants performed a reaction time task, and rated image vividness and difficulty of retrieving an image, during five speeds of EM and no EM. Both a high WM taxing frequency (fast EM; 1.2 Hz and a low WM taxing EM frequency (slow EM; 0.8 Hz were selected. In study 2, 72 participants recalled three highly vivid aversive autobiographical memory images (n=36 or three less vivid images (n=36 under each of three conditions: recall + fast EM, recall + slow EM or recall only. Multi-level modeling revealed a consistent pattern for all outcome measures: recall + fast EM led to less emotional, less vivid and more difficult to retrieve images than recall + slow EM and recall only, and the effects of recall + slow EM felt consistently in between the effects of recall + fast EM and recall only, but only differed significantly from recall + fast EM. Crucially, image vividness did not interact with condition on the decrease of emotionality over time, which was inconsistent with the prediction. Implications for understanding the mechanisms of action in memory modification and directions for future research are discussed.

  4. A Window on the Study of Aversive Instrumental Learning: Strains, Performance, Neuroendocrine, and Immunologic Systems

    Science.gov (United States)

    de Oliveira, Caroline C.; Gouveia, Flávia V.; de Castro, Marina C.; Kuroki, Mayra A.; dos Santos, Lennon C. T.; Fonoff, Erich T.; Teixeira, Manoel J.; Otoch, José P.; Martinez, Raquel C. R.

    2016-01-01

    The avoidance response is present in pathological anxiety and interferes with normal daily functions. The aim of this article is to shed light on performance markers of active avoidance (AA) using two different rat strains, Sprague-Dawley (SD) and Wistar. Specifically, good and poor performers were evaluated regarding anxiety traits exhibited in the elevated plus maze (EPM) and corticosterone levels and motor activity in the open field test. In addition, the plasma levels of Interleukin-6 (IL-6), Interleukin-1Beta (IL-1beta), Nerve Growth Factor Beta (NGF-beta), Tumor Necrosis Factor-Alpha (TNF-alpha) and cytokine-induced neutrophil chemoattractant 1 (CINC-1) were compared in the good and poor performers to better understand the role of the immunologic system in aversive learning. Behavioral criteria were employed to identify subpopulations of SD and Wistar rats based on their behavioral scores during a two-way AA test. The animals were tested for anxiety-like behavior in the EPM and motor activity in the open-field test. Plasma corticosterone levels were measured at the end of the avoidance test. Cytokine levels of IL-6, IL-1beta, NGF-beta, TNF-alpha, and CINC-1 were measured in the plasma of the Wistar rats. Sixty-six percent of the Wistar rats and 35% of the SD rats exhibited a poor performance. This feature was associated with a decrease in anxiety-like behavior in the EPM. The poor and good performers exhibited lower levels of corticosterone compared with the control animals, which suggests that training alters corticosterone levels, thereby leading to hypocortisolism, independent of the performance. The CINC-1 levels were increased in the poor performers, which reinforces the role of immunologic system activation in learning deficits. Our study provides a better understanding of the complex interactions that underlie neuroimmune consequences and their implications for performance.

  5. Do more graphic and aversive cigarette health warning labels affect Brazilian smokers' likelihood of quitting?

    Science.gov (United States)

    Szklo, André Salem; Volchan, Eliane; Thrasher, James F; Perez, Cristina; Szklo, Moysés; de Almeida, Liz Maria

    2016-09-01

    Between 2008 and 2013, Brazil experienced a large decline in smoking prevalence, with an innovative round of aversive pictorial health warnings implemented on cigarette packs and at points of sale in 2009. The objective of this study was to examine changes over time in the distribution of quitting attempts and self-reported thoughts about quitting due to health warnings among current smokers. We conducted a pre-post study to evaluate data from two nationally-representative surveys conducted in 2008 and 2013. Responses to questions on smokers' quitting attempts in the last year (yes vs. no) and whether health warnings led them to think about quitting in the last month (yes vs. no) were combined into four categories, for which the distribution of the Brazilian smoking population by year was estimated. A multinomial model was used to obtain proportions for each category, adjusted by socio-demographic variables and nicotine dependence. The proportion of smokers who reported making a quitting attempt in the last year and stated that health warnings led them think about quitting smoking statistically increased over time (from 30.0% to 33.1%; p-value=0.010). The percentage of those who answered "no" to these two questions also increased over time (from 23.5% to 32.9%; p-value≤0.001). These findings suggest that innovative warnings introduced in Brazil likely served as a "reminder" for continuing to think about cessation among those who attempted to quit in the last year. These warnings may have also triggered more avoidance of thinking about their contents than the previous warnings, which some studies have found to promote subsequent quitting activity. PMID:27161535

  6. Long term effects of aversive reinforcement on colour discrimination learning in free-flying bumblebees.

    Directory of Open Access Journals (Sweden)

    Miguel A Rodríguez-Gironés

    Full Text Available The results of behavioural experiments provide important information about the structure and information-processing abilities of the visual system. Nevertheless, if we want to infer from behavioural data how the visual system operates, it is important to know how different learning protocols affect performance and to devise protocols that minimise noise in the response of experimental subjects. The purpose of this work was to investigate how reinforcement schedule and individual variability affect the learning process in a colour discrimination task. Free-flying bumblebees were trained to discriminate between two perceptually similar colours. The target colour was associated with sucrose solution, and the distractor could be associated with water or quinine solution throughout the experiment, or with one substance during the first half of the experiment and the other during the second half. Both acquisition and final performance of the discrimination task (measured as proportion of correct choices were determined by the choice of reinforcer during the first half of the experiment: regardless of whether bees were trained with water or quinine during the second half of the experiment, bees trained with quinine during the first half learned the task faster and performed better during the whole experiment. Our results confirm that the choice of stimuli used during training affects the rate at which colour discrimination tasks are acquired and show that early contact with a strongly aversive stimulus can be sufficient to maintain high levels of attention during several hours. On the other hand, bees which took more time to decide on which flower to alight were more likely to make correct choices than bees which made fast decisions. This result supports the existence of a trade-off between foraging speed and accuracy, and highlights the importance of measuring choice latencies during behavioural experiments focusing on cognitive abilities.

  7. Estradiol enhances the acquisition of lithium chloride-induced conditioned taste aversion in castrated male rats

    Science.gov (United States)

    Lin, Shih-Fan; Tsai, Yuan-Feen; Tai, Mei-Yun; Yeh, Kuei-Ying

    2015-10-01

    The present study examined the effects of short-term treatment with ovarian hormones on the acquisition of conditioned taste aversion (CTA). Adult male rats were castrated and randomly divided into LiCl- and saline-treated groups. Nineteen days after castration, all of the animals were subjected to 23.5-h daily water deprivation for seven successive days (day 1 to day 7). On the conditioning day (day 8), the rats received either a 4 ml/kg of 0.15 M LiCl or the same dose of saline injection immediately after administration of a 2 % sucrose solution during the 30-min water session. Starting from day 6, rats in both groups received one of the following treatments: daily subcutaneous injection of (1) estradiol alone (30 μg/kg; estradiol benzoate (E) group), (2) estradiol plus progesterone (500 μg; E + progesterone (P) group), or (3) olive oil. From day 9 to day 11, all of the rats were given daily two-bottle preference tests during the 30-min fluid session. The estradiol and estradiol plus progesterone treatments in the LiCl groups resulted in significantly lower preference scores for the sucrose solution compared with the olive oil treatment groups, but no difference in preference score was seen between these two groups. These results indicate that both the estradiol and estradiol plus progesterone treatments in the LiCl groups enhanced the acquisition of CTA learning and suggest that estradiol affects the acquisition of CTA mediated by an activational effect in male rats, whereas progesterone treatment does not influence the effects of estradiol on the acquisition of CTA.

  8. Activity-dependent structural plasticity after aversive experiences in amygdala and auditory cortex pyramidal neurons.

    Science.gov (United States)

    Gruene, Tina; Flick, Katelyn; Rendall, Sam; Cho, Jin Hyung; Gray, Jesse; Shansky, Rebecca

    2016-07-22

    The brain is highly plastic and undergoes changes in response to many experiences. Learning especially can induce structural remodeling of dendritic spines, which is thought to relate to memory formation. Classical Pavlovian fear conditioning (FC) traditionally pairs an auditory cue with an aversive footshock, and has been widely used to study neural processes underlying associative learning and memory. Past research has found dendritic spine changes after FC in several structures. But, due to heterogeneity of cells within brain structures and limitations of traditional neuroanatomical techniques, it is unclear if all cells included in analyses were actually active during learning processes, even if known circuits are isolated. In this study, we employed a novel approach to analyze structural plasticity explicitly in neurons activated by exposure to either cued or uncued footshocks. We used male and female Arc-dVenus transgenic mice, which express the Venus fluorophore driven by the activity-related Arc promoter, to identify neurons that were active during either scenario. We then targeted fluorescent microinjections to Arc+ and neighboring Arc- neurons in the basolateral area of the amygdala (BLA) and auditory association cortex (TeA). In both BLA and TeA, Arc+ neurons had reduced thin and mushroom spine densities compared to Arc- neurons. This effect was present in males and females alike and also in both cued and uncued shock groups. Overall, this study adds to our understanding of how neuronal activity affects structural plasticity, and represents a methodological advance in the ways we can directly relate structural changes to experience-related neural activity. PMID:27155146

  9. The role of the COMT val158met polymorphism in mediating aversive learning in visual cortex.

    Science.gov (United States)

    Gruss, L Forest; Langaee, Taimour; Keil, Andreas

    2016-01-15

    The catechol-O-methyltransferase (COMT) val158met single nucleotide polymorphism (SNP) alters metabolic activity of the COMT enzyme regulating catecholamines, with the Val (valine) allele resulting in 40% greater enzymatic activity than the Met (methionine) allele. Previous research has identified systematic inter-individual differences in cognitive and behavioral phenotypes related to this polymorphism, often attributed to the fact that extracellular dopamine in the prefrontal cortex is strongly affected by the COMT enzyme. The neurophysiological mechanisms mediating these inter-individual differences in specific brain systems and task contexts remain to be established however. In the current study, we examined the extent to which physio-mechanistic differences by COMT genotype affect somato-visceral and visual cortical responses to learned threat cues. Classical aversive differential conditioning was implemented using rapidly phase-reversing grating stimuli, previously shown to engage retinotopic visual cortex. Differential response patterns in sensory and autonomic systems were elicited by pairing one grating (CS+, conditioned stimulus), but not the other (CS-), with a noxious stimulus. Dense-array electroencephalography and somato-visceral measures of defensive reactivity were recorded in addition to self-report data. Individuals of the Val/Val genotype, compared to Met allele carriers, reliably showed greater initial enhancement in their visuocortical response to the CS+, accompanied by stronger defensive engagement, indexed by heart rate acceleration and startle potentiation. The finding that COMT polymorphism status affects threat cue reactivity at the visuocortical level is consistent with the notion that sensory processing of threat is facilitated by strong re-entrant bias signals from anterior areas, including the prefrontal cortex. PMID:26549298

  10. Proton Therapy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Proton Therapy Proton therapy delivers radiation to tumor tissue ... feel during and after the procedure? What is proton therapy and how is it used? Protons are ...

  11. Sex differences in the effects of ethanol pre-exposure during adolescence on ethanol-induced conditioned taste aversion in adult rats.

    Science.gov (United States)

    Sherrill, Luke K; Berthold, Claire; Koss, Wendy A; Juraska, Janice M; Gulley, Joshua M

    2011-11-20

    Alcohol use, which typically begins during adolescence and differs between males and females, is influenced by both the rewarding and aversive properties of the drug. One way adolescent alcohol use may modulate later consumption is by reducing alcohol's aversive properties. Here, we used a conditioned taste aversion (CTA) paradigm to determine if pre-exposure to alcohol (ethanol) during adolescence would attenuate ethanol-induced CTA assessed in adulthood in a sex-dependent manner. Male and female Long-Evans rats were given intraperitoneal (i.p.) injections of saline or 3.0g/kg ethanol in a binge-like pattern during postnatal days (PD) 35-45. In adulthood (>PD 100), rats were given access to 0.1% saccharin, followed by saline or ethanol (1.0 or 1.5g/kg, i.p.), over four conditioning sessions. We found sex differences in ethanol-induced CTA, with males developing a more robust aversion earlier in conditioning. Sex differences in the effects of pre-exposure were also evident: males, but not females, showed an attenuated CTA in adulthood following ethanol pre-exposure, which occurred approximately nine weeks earlier. Taken together, these findings indicate that males are more sensitive to the aversive properties of ethanol than females. In addition, the ability of pre-exposure to the ethanol US to attenuate CTA is enhanced in males compared to females. PMID:21767576

  12. p38 mitogen-activated protein kinase activation in amygdala mediates κ opioid receptor agonist U50,488H-induced conditioned place aversion.

    Science.gov (United States)

    Zan, G-Y; Wang, Q; Wang, Y-J; Chen, J-C; Wu, X; Yang, C-H; Chai, J-R; Li, M; Liu, Y; Hu, X-W; Shu, X-H; Liu, J-G

    2016-04-21

    κ opioid receptor agonists produce aversive effects in rodents, however the underlying mechanisms remain unclear. Activation of p38 mitogen-activated protein kinase (MAPK) has been discovered to play a critical role in the modulation of affective behaviors. The present study was undertaken to detect the possible involvement of p38 MAPK in the aversive effects induced by κ opioid receptor activation. We found that the κ opioid receptor agonist trans-(±)-3,4-Dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]benzenacetamide methanesulfonate salt (U50,488H) produced significant place aversion in mice as measured by the conditioned place preference procedure, accompanied with significant p38 MAPK activation in the amygdala, but not in the nucleus accumbens and hippocampus. Stereotaxic microinjection of the p38 MAPK inhibitor 4-(4-fluorophenyl)-2-(4-methylsulfonylphenyl)-5-(4-pyridy-l)-1H-imidazole (SB203580) into amygdala significantly inhibited p38 MAPK activation and completely blocked the conditioned place aversion in mice. Thus, these results suggested that activation of p38 MAPK in the amygdala was required to mediate κ opioid receptor-induced aversive behavior. PMID:26826330

  13. Impaired Reality Testing in Mice Lacking Phospholipase Cβ1: Observed by Persistent Representation-Mediated Taste Aversion.

    Science.gov (United States)

    Kim, Hea-Jin; Koh, Hae-Young

    2016-01-01

    Hallucinations and delusions are the most prominent symptoms of schizophrenia and characterized by impaired reality testing. Representation-mediated taste aversion (RMTA) has been proposed as a potential behavioral assessment of reality testing and has been applied to a neurodevelopmental rat model of schizophrenia. However, the theory underlying this approach has not been generalized yet with any demonstration of impaired reality testing in other animal models of schizophrenia, such as genetically-modified mice. We devised a RMTA procedure for mice that combines a Pavlovian association protocol pairing odor conditioned stimulus (CS) with sugar reward unconditioned stimulus (US), and a conditioned taste aversion (CTA) method. In this RMTA paradigm, we compared performances of wild-type (PLCβ1+/+) mice and phospholipase C β1 knock-out (PLCβ1-/-) mice which are known as one of the genetic models for schizophrenia. With a minimal amount of initial odor-sugar associative training, both PLCβ1+/+ and PLCβ1-/- mice were able to form an aversion to the sugar reward when the odor CS predicting sugar was paired with nausea. With an extended initial training, however, only PLCβ1-/- mice could form a RMTA. This persistent RMTA displayed by PLCβ1-/- mice shows their inability to distinguish real sugar from the CS-evoked representation of sugar at a stage in associative learning where wild-type mice normally could differentiate the two. These results demonstrate an impaired reality testing first observed in a genetic mouse model of schizophrenia, and suggest that RMTA paradigm may, with general applicability, allow diverse biological approaches to impaired reality testing. PMID:26731530

  14. Impaired Reality Testing in Mice Lacking Phospholipase Cβ1: Observed by Persistent Representation-Mediated Taste Aversion.

    Directory of Open Access Journals (Sweden)

    Hea-Jin Kim

    Full Text Available Hallucinations and delusions are the most prominent symptoms of schizophrenia and characterized by impaired reality testing. Representation-mediated taste aversion (RMTA has been proposed as a potential behavioral assessment of reality testing and has been applied to a neurodevelopmental rat model of schizophrenia. However, the theory underlying this approach has not been generalized yet with any demonstration of impaired reality testing in other animal models of schizophrenia, such as genetically-modified mice. We devised a RMTA procedure for mice that combines a Pavlovian association protocol pairing odor conditioned stimulus (CS with sugar reward unconditioned stimulus (US, and a conditioned taste aversion (CTA method. In this RMTA paradigm, we compared performances of wild-type (PLCβ1+/+ mice and phospholipase C β1 knock-out (PLCβ1-/- mice which are known as one of the genetic models for schizophrenia. With a minimal amount of initial odor-sugar associative training, both PLCβ1+/+ and PLCβ1-/- mice were able to form an aversion to the sugar reward when the odor CS predicting sugar was paired with nausea. With an extended initial training, however, only PLCβ1-/- mice could form a RMTA. This persistent RMTA displayed by PLCβ1-/- mice shows their inability to distinguish real sugar from the CS-evoked representation of sugar at a stage in associative learning where wild-type mice normally could differentiate the two. These results demonstrate an impaired reality testing first observed in a genetic mouse model of schizophrenia, and suggest that RMTA paradigm may, with general applicability, allow diverse biological approaches to impaired reality testing.

  15. Depletion of nucleus accumbens dopamine leads to impaired reward and aversion processing in mice: Relevance to motivation pathologies.

    Science.gov (United States)

    Bergamini, Giorgio; Sigrist, Hannes; Ferger, Boris; Singewald, Nicolas; Seifritz, Erich; Pryce, Christopher R

    2016-10-01

    Dopamine (DA) neurotransmission, particularly the ventral tegmental area-nucleus accumbens (VTA-NAcc) projection, underlies reward and aversion processing, and deficient DA function could underlie motivational impairments in psychiatric disorders. 6-hydroxydopamine (6-OHDA) injection is an established method for chronic DA depletion, principally applied in rat to study NAcc DA regulation of reward motivation. Given the increasing focus on studying environmental and genetic regulation of DA function in mouse models, it is important to establish the effects of 6-OHDA DA depletion in mice, in terms of reward and aversion processing. This mouse study investigated effects of 6-OHDA-induced NAcc DA depletion using the operant behavioural test battery of progressive ratio schedule (PRS), learned non-reward (LNR), learned helplessness (LH), treadmill, and in addition Pavlovian fear conditioning. 6-OHDA NAcc DA depletion, confirmed by ex vivo HPLC-ED, reduced operant responding: for gustatory reward under effortful conditions in the PRS test; to a stimulus recently associated with gustatory non-reward in the LNR test; to escape footshock recently experienced as uncontrollable in the LH test; and to avoid footshock by physical effort in the treadmill test. Evidence for specificity of effects to NAcc DA was provided by lack of effect of medial prefrontal cortex DA depletion in the LNR and LH tests. These findings add significantly to the evidence that NAcc DA is a major regulator of behavioural responding, particularly at the motivational level, to both reward and aversion. They demonstrate the suitability of mouse models for translational study of causation and reversal of pathophysiological DA function underlying motivation psychopathologies. PMID:27036890

  16. THE FORMATION OF CONSUMER’S PERCEIVED RISK AND RISK AVERSION IN THE CONTEXT OF INNOVATION ADOPTION: A QUALITATIVE RESEARCH

    Directory of Open Access Journals (Sweden)

    Dorian-Laurentiu FLOREA

    2014-12-01

    Full Text Available The level of perceived risk is acknowledged to determine the innovation adoption decision. Yet, despite being largely studied in a manifold of disciplines, we still have a poor understanding of its formation from a marketing perspective. This paper offers valuable insight on how perceived risk and risk aversion evolve under different conditions and how the influence on adoption decision is made. We perform two focus groups and 10 in-depth interviews that enable us to build several counterintuitive paths that refute previous findings. Implications for management and science are discussed and a new theory is proposed.

  17. Periaqueductal gray c-Fos expression varies relative to the method of conditioned taste aversion extinction employed

    OpenAIRE

    Mickley, G Andrew; Wilson, Gina N.; Remus, Jennifer L.; Ramos, Linnet; Ketchesin, Kyle D.; Biesan, Orion R.; Luchsinger, Joseph R.; Prodan, Suzanna

    2011-01-01

    A conditioned taste aversion (CTA) is acquired when an animal consumes a novel taste (CS) and then experiences the symptoms of poisoning (US). Following CTA training, animals will avoid the taste that was previously associated with malaise. This defensive reaction to a learned fear can be extinguished by repeated exposure to the CS alone (CS-only; CSO-EXT). However, following a latency period in which the CS is not presented, the CTA will spontaneously recover (SR). Through the use of an expl...

  18. Nurses' experiences of leech therapy in plastic and reconstructive surgery.

    Science.gov (United States)

    Reynolds, Alison; OBoyle, Colm

    2016-07-14

    The aim of this study was to explore nurses' experience of using leech therapy. Leech therapy is useful in promoting revascularisation of skin grafts. Nurse disquiet in their role as leech therapists has been noted. This study explored the experience of Irish nurses. A qualitative design with an interview schedule was used to learn about emotional and practical clinical experiences. Interviews were carried out with seven nurses working with leeches in reconstructive surgery in 2013. These interviews were coded and explored for themes. Results revealed that many nurses feel aversion to the use of leeches. This may be associated with the use of a parasitic organism as treatment in conflict with the nurse's role in cross infection. It was also found that management of a nurse's own and patient's emotional responses is required. In conclusion, preparation for the role of leech therapy beyond the purely practical is necessary, and should explore affective responses of the practitioner and patients. PMID:27409780

  19. 风险规避型供应链的收益共享机制研究%Revenue Sharing Contract Mechanisms of Risk-Averse Supply Chains

    Institute of Scientific and Technical Information of China (English)

    叶飞; 林强

    2012-01-01

    Market demand uncertainty brings risks to supply chain members. All members have different risk preferences. For example, risk-averse members tend to choose conservative decision-making behaviors. In contrast, risk-taking members seek high risks and returns. Therefore, the design of supply chain coordination mechanisms should take the risk attitudes of supply chain members into consideration.The risk-averse decision maker behaves conservatively to mitigate risks in certain ways. If a supply chain contains risk-averse firm (s) , we consider it as a risk-averse supply chain. Recently, studies on supply chain coordination and optimization with risk-averse decision makers have attracted extensive attentions. However, most existing models of this setting only consider single risk-averse supply chain member. Very few studies take both risk-averse suppliers and retailers into account. This study focuses on the supply chain coordination problem by considering both supplier and retailer are risk aversion decision-makers. Another objective of this study is to provide an in-depth analysis on how risk sensitivity affects the optimal decision-making behavior, and how these dynamics are altered by the coordination contract mechanism.Under the mean-variance value function, we investigate decision-making behaviors using the Stackelberg game model to analyze the behavior of risk-averse retailers and risk-averse suppliers, and the impact of risk-aversion coefficient on both sides of decision.Then, under the vertical integration model we study the risk-averse supply chain's decision behavior and analyze the impact of both risk-aversion coefficients on the optimal decision-making behavior. By comparing the analysis of Stackelberg and vertical integration model, the results show that the risk-averse supply chain collaboration enhances the overall effectiveness. This finding suggests revenue sharing mechanisms be used to coordinate the supply chain.In addition, there are three major

  20. Speed Matters: Relationship between Speed of Eye Movements and Modification of Aversive Autobiographical Memories.

    Science.gov (United States)

    van Veen, Suzanne Chantal; van Schie, Kevin; Wijngaards-de Meij, Leoniek D N V; Littel, Marianne; Engelhard, Iris M; van den Hout, Marcel A

    2015-01-01

    Eye movement desensitization and reprocessing (EMDR) is an efficacious treatment for post-traumatic stress disorder. In EMDR, patients recall a distressing memory and simultaneously make eye movements (EM). Both tasks are considered to require limited working memory (WM) resources. Because this leaves fewer resources available for memory retrieval, the memory should become less vivid and less emotional during future recall. In EMDR analogue studies, a standardized procedure has been used, in which participants receive the same dual task manipulation of 1 EM cycle per second (1 Hz). From a WM perspective, the WM taxation of the dual task might be titrated to the WM taxation of the memory image. We hypothesized that highly vivid images are more affected by high WM taxation and less vivid images are more affected by low WM taxation. In study 1, 34 participants performed a reaction time task, and rated image vividness, and difficulty of retrieving an image, during five speeds of EM and no EM. Both a high WM taxing frequency (fast EM; 1.2 Hz) and a low WM taxing frequency (slow EM; 0.8 Hz) were selected. In study 2, 72 participants recalled three highly vivid aversive autobiographical memory images (n = 36) or three less vivid images (n = 36) under each of three conditions: recall + fast EM, recall + slow EM, or recall only. Multi-level modeling revealed a consistent pattern for all outcome measures: recall + fast EM led to less emotional, less vivid and more difficult to retrieve images than recall + slow EM and recall only, and the effects of recall + slow EM felt consistently in between the effects of recall + fast EM and recall only, but only differed significantly from recall + fast EM. Crucially, image vividness did not interact with condition on the decrease of emotionality over time, which was inconsistent with the prediction. Implications for understanding the mechanisms of action in memory modification and directions for

  1. Baclofen alters gustatory discrimination capabilities and induces a conditioned taste aversion (CTA

    Directory of Open Access Journals (Sweden)

    Wilson Gina N

    2011-12-01

    Full Text Available Abstract Background Studies intending to measure drug-induced changes in learning and memory are challenged to parse out the effects of drugs on sensory, motor, and associative systems in the brain. In the context of conditioned taste aversion (CTA, drugs that alter the sensorium of subjects and affect their ability to taste and/or feel malaise may limit the ability of investigators to make conclusions about associative effects of these substances. Since the GABAergic system is implicated in inhibition, the authors were hopeful to use the GABA agonist, baclofen (BAC, to enhance extinction of a CTA, but first a preliminary evaluation of BAC's peripheral effects on animals' sensorium had to be completed due to a lack of published literature in this area. Findings Our first experiment aimed to evaluate the extent to which the GABAB agonist, BAC, altered the ability of rats to differentiate between 0.3% and 0.6% saccharin (SAC in a two bottle preference test. Here we report that 2 or 3 mg/kg (i.p. BAC, but not 1 mg/kg BAC, impaired animals' gustatory discrimination abilities in this task. Furthermore, when SAC consumption was preceded by 2 or 3 mg/kg (i.p. BAC, rats depressed their subsequent SAC drinking. A second experiment evaluated if the suppression of SAC and water drinking (revealed in Experiment 1 was mediated by amnesiac effects of BAC or whether BAC possessed US properties in the context of the CTA paradigm. The time necessary to reach an asymptotic level of CTA extinction was not significantly different in those animals that received the 3 mg/kg dose of BAC compared to more conventionally SAC + lithium chloride (LiCl, 81 mg/kg conditioned animals. Conclusions Our findings were not consistent with a simple amnesia-of-neophobia explanation. Instead, results indicated that 2 and 3 mg/kg (i.p. BAC were capable of inducing a CTA, which was extinguishable via repeated presentations of SAC only. Our data indicate that, depending on the dose, BAC

  2. [Pharmacological support of exposure therapy in anxiety disorders. Animal experiment studies].

    Science.gov (United States)

    Koch, M

    2002-05-01

    The fear-potentiated startle paradigm (i.e., the enhancement of the startle response in the presence of an aversive conditioned stimulus) is a valuable cross-species model for the study of the neuronal mechanisms underlying fear and anxiety as well as of the cognitive control of those aversive states. Walker et al. present data from a study in rats indicating that extinction of fear in the fear-potentiated startle paradigm is enhanced by the partial agonist of the N-methyl-D-aspartate receptor D-cycloserine (DCS). The authors therefore suggest tests of DCS in clinical trials as a potential pharmacotherapeutic adjuvant for exposition therapies in fear and anxiety disorders. PMID:12078031

  3. Explicit disassociation of a conditioned stimulus and unconditioned stimulus during extinction training reduces both time to asymptotic extinction and spontaneous recovery of a conditioned taste aversion

    OpenAIRE

    Mickley, G Andrew; DiSorbo, Anthony; Wilson, Gina N.; Huffman, Jennifer; Bacik, Stephanie; Hoxha, Zana; Biada, Jaclyn M.; Kim, Ye-Hyun

    2009-01-01

    Conditioned taste aversions (CTAs) may be acquired when an animal consumes a novel taste (CS) and then experiences the symptoms of poisoning (US). This aversion may be extinguished by repeated exposure to the CS alone. However, following a latency period in which the CS is not presented, the CTA will spontaneously recover (SR). In the current study we employed an explicitly unpaired extinction procedure (EU-EXT) to determine if it could thwart SR of a CTA. Sprague-Dawley rats acquired a stron...

  4. Binge ethanol exposure in late gestation induces ethanol aversion in the dam but enhances ethanol intake in the offspring and affects their postnatal learning about ethanol

    OpenAIRE

    Chotro, M. Gabriela; Arias, Carlos; Norman E. Spear

    2009-01-01

    Previous studies show that exposure to 1 or 2 g/kg ethanol during the last days of gestation increases ethanol acceptance in infant rats. We tested whether prenatal exposure to 3 g/kg, a relatively high ethanol dose, generates an aversion to ethanol in both the dam and offspring, and whether this prenatal experience affects the expression of learning derived from ethanol exposure postnatally. The answer was uncertain, since postnatal administration of a 3 g/kg ethanol dose induces an aversion...

  5. Enhancement of Inhibitory Avoidance and Conditioned Taste Aversion Memory With Insular Cortex Infusions of 8-Br-cAMP: Involvement of the Basolateral Amygdala

    OpenAIRE

    Miranda, María I.; McGaugh, James L.

    2004-01-01

    There is considerable evidence that in rats, the insular cortex (IC) and amygdala are involved in the learning and memory of aversively motivated tasks. The present experiments examined the effects of 8-Br-cAMP, an analog of cAMP, and oxotremorine, a muscarinic agonist, infused into the IC after inhibitory avoidance (IA) training and during the acquisition/consolidation of conditioned taste aversion (CTA). Posttraining infusion into the IC of 0.3 μg oxotremorine and 1.25 μg 8-Br-cAMP enhanced...

  6. fMRI evidence of a hot-cold empathy gap in hypothetical and real aversive choices.

    Science.gov (United States)

    Kang, Min J; Camerer, Colin F

    2013-01-01

    Hypothetical bias is the common finding that hypothetical monetary values for "goods" are higher than real values. We extend this research to the domain of "bads" such as consumer and household choices made to avoid aversive outcomes (e.g., insurance). Previous evidence of hot-cold empathy gaps suggest food disgust is likely to be strongly underestimated in hypothetical (cold) choice. Depending on relative underestimation of food disgust and pain of spending, the hypothetical bias for aversive bad scan go in the typical direction for goods, disappear, or reverse in sign. We find that the bias is reversed in sign-subjects pay more to avoid bads when choice is real. fMRI shows that real choice more strongly activates striatum and medial prefrontal cortex (reward regions) and shows distinct activity in insula and amygdala (disgust and fear regions). The neural findings suggest ways to exogeneously manipulate or record brain activity in order to create better forecasts of actual consumer choice. PMID:23772205

  7. Investigation on Habit Formation, Risk Aversion and Intertemporal Substitution in Consumption of Iranian Households by GMM Approach

    Directory of Open Access Journals (Sweden)

    Reza Roshan

    2013-01-01

    Full Text Available Consumption is the principal feature of Iran’s Gross National Production. Therefore, recognizing of factors that influence it is quite crucial. This article, investigates habit formation, durability, relative risk aversion and intertemporal substitution in consumption expenditures of Iranian households. For empirical study, at first, we constructed two weighted portfolio of the main assets return that households hold them. Then, by using generalized method of moments, we examined some models with the mentioned factors in pattern of households’ consumption for 1979-2012 periods. Our Empirical findings indicated that for durable goods, the effect of habit persistence dominated the effect of durability in consumption expenditures and for semi durable goods vice versa. Also, for semi-durable and durable goods the effect of durability dominated the effect of habit formation. Furthermore, the results indicate that coefficients of relative risk aversion and elasticity of intertemporal substitution are between 0.25 to 0.95 and 1.05 to 4, respectively.

  8. An inexact mixed risk-aversion two-stage stochastic programming model for water resources management under uncertainty.

    Science.gov (United States)

    Li, W; Wang, B; Xie, Y L; Huang, G H; Liu, L

    2015-02-01

    Uncertainties exist in the water resources system, while traditional two-stage stochastic programming is risk-neutral and compares the random variables (e.g., total benefit) to identify the best decisions. To deal with the risk issues, a risk-aversion inexact two-stage stochastic programming model is developed for water resources management under uncertainty. The model was a hybrid methodology of interval-parameter programming, conditional value-at-risk measure, and a general two-stage stochastic programming framework. The method extends on the traditional two-stage stochastic programming method by enabling uncertainties presented as probability density functions and discrete intervals to be effectively incorporated within the optimization framework. It could not only provide information on the benefits of the allocation plan to the decision makers but also measure the extreme expected loss on the second-stage penalty cost. The developed model was applied to a hypothetical case of water resources management. Results showed that that could help managers generate feasible and balanced risk-aversion allocation plans, and analyze the trade-offs between system stability and economy. PMID:25226833

  9. Distinct Patterns of Dysfunctional Appetitive and Aversive Motivation in Bipolar Disorder Versus Schizophrenia: An Event Related Potential Study

    Science.gov (United States)

    Horan, William P.; Wynn, Jonathan K.; Hajcak, Greg; Altshuler, Lori; Green, Michael F.

    2016-01-01

    Schizophrenia and bipolar disorder are associated with different clinical profiles of disturbances in motivation, yet few studies have compared the neurophysiological correlates of such disturbances. Outpatients with schizophrenia (n = 34), or bipolar disorder I (n = 33), and healthy controls (n = 31) completed a task in which the Late Positive Potential (LPP), an index of motivated attention, was assessed along motivational gradients determined by apparent distance from potential rewards or punishments. Sequences of cues signaling possible monetary gains or losses appeared to loom progressively closer to the viewer; a reaction time (RT) task after the final cue determined the outcome. Controls showed the expected pattern with LPPs for appetitive and aversive cues that were initially elevated, smaller during intermediate positions, and escalated just prior to the RT task. The clinical groups showed different patterns in the final positions just prior to the RT task: the bipolar group’s LPPs to both types of cues peaked relatively early during looming sequences and subsequently decreased, whereas the schizophrenia group showed relatively small LPP escalations, particularly for aversive cues. These distinct patterns suggest that the temporal unfolding of attentional resource allocation for motivationally significant events may qualitatively differ between these disorders. PMID:26845261

  10. Distinct patterns of dysfunctional appetitive and aversive motivation in bipolar disorder versus schizophrenia: An event-related potential study.

    Science.gov (United States)

    Horan, William P; Wynn, Jonathan K; Hajcak, Greg; Altshuler, Lori; Green, Michael F

    2016-05-01

    Schizophrenia and bipolar disorder are associated with different clinical profiles of disturbances in motivation, yet few studies have compared the neurophysiological correlates of such disturbances. Outpatients with schizophrenia (n = 34), or bipolar disorder I (n = 33), and healthy controls (n = 31) completed a task in which the late positive potential (LPP), an index of motivated attention, was assessed along motivational gradients determined by apparent distance from potential rewards or punishments. Sequences of cues signaling possible monetary gains or losses appeared to loom progressively closer to the viewer; a reaction time (RT) task after the final cue determined the outcome. Controls showed the expected pattern with LPPs for appetitive and aversive cues that were initially elevated, smaller during intermediate positions, and escalated just prior to the RT task. The clinical groups showed different patterns in the final positions just prior to the RT task: the bipolar group's LPPs to both types of cues peaked relatively early during looming sequences and subsequently decreased, whereas the schizophrenia group showed relatively small LPP escalations, particularly for aversive cues. These distinct patterns suggest that the temporal unfolding of attentional resource allocation for motivationally significant events may qualitatively differ between these disorders. (PsycINFO Database Record PMID:26845261

  11. Inhibition of mammalian target of rapamycin activation in the rostral anterior cingulate cortex attenuates pain-related aversion in rats.

    Science.gov (United States)

    Lu, Bo; Jiang, Jingyan; Sun, Jianliang; Xiao, Chun; Meng, Bo; Zheng, Jinwei; Li, Xiaoyu; Wang, Ruichun; Wu, Guorong; Chen, Junping

    2016-09-01

    Pain is a complex experience that comprises both sensory and affective dimensions. Mammalian target of rapamycin (mTOR) plays an important role in the modulation of neuronal plasticity associated with the pathogenesis of pain sensation. However, the role of mTOR in pain affect is unclear. Using a formalin-induced conditioned place avoidance (F-CPA) test, the current study investigated the effects of the mTOR specific inhibitor rapamycin on noxious stimulation induced aversion in the rostral anterior cingulate cortex (rACC). Intraplantar injection of 5% formalin was associated with significant activation of mTOR, as well as p70 ribosomal S6 protein (p70S6K), its downstream effector, in the rACC. The inhibition of mTOR activation with rapamycin disrupted pain-related aversion; however, this inhibition did not affect formalin-induced spontaneous nociceptive behaviors in rats. These findings demonstrated for the first time that mTOR and its downstream pathway in the rACC contribute to the induction of pain-related negative emotion. PMID:27163752

  12. Radiation Therapy

    Science.gov (United States)

    ... therapy. At this time, you will have a physical exam , talk about your medical history , and maybe have imaging tests . Your doctor or nurse will discuss external beam radiation therapy, its benefits and side effects, and ways you can care ...

  13. Paradoxical increase of exploratory behavior in the elevated plus-maze by rats exposed to two kinds of aversive stimuli

    Directory of Open Access Journals (Sweden)

    Morato S.

    1997-01-01

    Full Text Available Albino rats were submitted to a 24-h period of social isolation (individual housing combined with 0, 1, 2 or 3 twenty-four-hour periods of exposure to different vivaria (novelty and tested in the elevated plus-maze. Results, reported as mean ± SEM for N = 12, show that the time (in seconds spent in the open arms by rats exposed to novelty for 0, 1, 2 and 3 days was 28.3 ± 4.4, 31.6 ± 3.2, 29.1 ± 3.5 and 25.0 ± 3.3, respectively, when grouped in the same vivarium; 29.6 ± 2.7, 7.6 ± 2.1, 9.6 ± 4.4 and 28.5 ± 3.7 when grouped in different vivaria; 2.9 ± 1.1, 1.8 ± 1.0, 2.7 ± 1.1 and 0 ± 0 when isolated in the same vivarium, and 2.6 ± 1.1, 31.5 ± 8.2, 24.8 ± 4.2 and 0 ± 0 when isolated in different vivaria. The number of entries into the open and closed arms followed a similar trend. This indicates that, separately, both exposure to novelty and isolation are aversive manipulations. Paradoxically, when novelty was combined with a concomitant 24-h period of social isolation prior to testing, the decrease in exploratory behavior caused by either of the two aversive manipulations alone was reverted. These results are indicative that less intense anxiety triggers mechanisms mediating less energetic behavior such as freezing, while higher levels trigger mechanisms mediating more vigorous action, such as flight/fight behavior, since the combination of two aversive situations resulted in more exploratory behavior than with either alone. They are also suggestive of habituation to the effects of novelty, since exposure to it for 3 days produced exploratory behavior similar to that of controls

  14. Therapy Services.

    Science.gov (United States)

    Austin Independent School District, TX.

    Reviewed are the goals and activities of the therapy services in the Austin Early Childhood Special Education Program. Specific sections detail activities for speech therapy (such as diagnostic assessment, habilitation, consultation, and reporting procedures), occupational therapy (including identification and assessment, and services to children,…

  15. Application of a General Risk Management Model to Portfolio Optimization Problems with Elliptical Distributed Returns for Risk Neutral and Risk Averse Decision Makers

    NARCIS (Netherlands)

    B. Kaynar; S.I. Birbil (Ilker); J.B.G. Frenk (Hans)

    2007-01-01

    textabstractIn this paper portfolio problems with linear loss functions and multivariate elliptical distributed returns are studied. We consider two risk measures, Value-at-Risk and Conditional-Value-at-Risk, and two types of decision makers, risk neutral and risk averse. For Value-at-Risk, we show

  16. Which Jews dislike contemporary Germans: Range and determinants of German aversion in Czech and U.S. Holocaust survivors and young American Jews

    Czech Academy of Sciences Publication Activity Database

    Rozin, P.; Cherfas, L.; Radil, Tomáš; Radilová, Jiřina; McCauley, C. R.; Cohen, A.B.

    2014-01-01

    Roč. 20, č. 4 (2014), s. 412-429. ISSN 1078-1919 R&D Projects: GA ČR(CZ) GAP407/10/2031 Institutional support: RVO:67985823 Keywords : ethnic aversions * forgiveness * Germans * Holocaust survivors * Jews * social perception * trauma Subject RIV: AN - Psychology

  17. Punishment and Aversive Stimulation in Special Education: Legal, Theoretical and Practical Issues in Their Use with Emotionally Disturbed Children and Youth.

    Science.gov (United States)

    Wood, Frank H., Ed.; Lakin, K. Charlie, Ed.

    Seven papers from a 1978 conference focus on the use of punishment in special education programs for emotionally disturbed students. In "The Legal Status of the Use of Corporal Punishment and Other Aversive Procedures in Schools," F. Wood and K. Lakin review laws, regulations, and court decisions that bear on the legality of the use of corporal…

  18. Smart Grid Charging of Electric Vehicles: EV-Owner Response to Scheduling and Pricing under Myopic Loss Aversion in an Ultimatum Two-Player Game

    DEFF Research Database (Denmark)

    Fetene, Gebeyehu Manie; Kaplan, Sigal; Sebald, Alexander Christopher;

    2015-01-01

    affected by myopic loss aversion resulting from monetary considerations as well as the ultimatum game with the supplier; (ii) EV-owners are open towards centralized smart-grid strategies optimizing the load on the grid from a system optimum perspective; (iii) the frequency of charging decisions (daily...

  19. Mice infected with low-virulence strains of Toxoplasma gondii lose their innate aversion to cat urine, even after extensive parasite clearance.

    Directory of Open Access Journals (Sweden)

    Wendy Marie Ingram

    Full Text Available Toxoplasma gondii chronic infection in rodent secondary hosts has been reported to lead to a loss of innate, hard-wired fear toward cats, its primary host. However the generality of this response across T. gondii strains and the underlying mechanism for this pathogen-mediated behavioral change remain unknown. To begin exploring these questions, we evaluated the effects of infection with two previously uninvestigated isolates from the three major North American clonal lineages of T. gondii, Type III and an attenuated strain of Type I. Using an hour-long open field activity assay optimized for this purpose, we measured mouse aversion toward predator and non-predator urines. We show that loss of innate aversion of cat urine is a general trait caused by infection with any of the three major clonal lineages of parasite. Surprisingly, we found that infection with the attenuated Type I parasite results in sustained loss of aversion at times post infection when neither parasite nor ongoing brain inflammation were detectable. This suggests that T. gondii-mediated interruption of mouse innate aversion toward cat urine may occur during early acute infection in a permanent manner, not requiring persistence of parasite cysts or continuing brain inflammation.

  20. You don't have to be well-educated to be an aversive racist, but it helps.

    Science.gov (United States)

    Kuppens, Toon; Spears, Russell

    2014-05-01

    People with higher levels of formal education report less prejudice in survey research. Here we present novel evidence on the nature of educational differences in anti-Black attitudes among Whites. We replicate the education effect on explicit self-report measures of anti-Black attitudes, but we find that education is much less related to implicit measures of anti-Black attitudes. Implicit measures differ from explicit measures in that they do not allow respondents to control the measurement outcome; they therefore measure more spontaneous aspects of attitudes. These results shed new light on intergroup attitudes of the higher educated. Higher educated people are more likely to be aversive racists, that is, to score low on explicit, but not implicit measures of prejudice. Given the differential relation of explicit versus implicit measures to behavior, they have wide-ranging implications for the kind of intergroup behavior and discrimination we can expect from less and more highly educated people. PMID:24576637

  1. Role of IKK/NF-κB signaling in extinction of conditioned place aversion memory in rats.

    Directory of Open Access Journals (Sweden)

    Cheng-Hao Yang

    Full Text Available The inhibitor κB protein kinase/nuclear factor κB (IKK/NF-κB signaling pathway is critical for synaptic plasticity. However, the role of IKK/NF-κB in drug withdrawal-associated conditioned place aversion (CPA memory is unknown. Here, we showed that inhibition of IKK/NF-κB by sulphasalazine (SSZ; 10 mM, i.c.v. selectively blocked the extinction but not acquisition or expression of morphine-induced CPA in rats. The blockade of CPA extinction induced by SSZ was abolished by sodium butyrate, an inhibitor of histone deacetylase. Thus, the IKK/NF-κB signaling pathway might play a critical role in the extinction of morphine-induced CPA in rats and might be a potential pharmacotherapy target for opiate addiction.

  2. Instructed knowledge shapes feedback-driven aversive learning in striatum and orbitofrontal cortex, but not the amygdala.

    Science.gov (United States)

    Atlas, Lauren Y; Doll, Bradley B; Li, Jian; Daw, Nathaniel D; Phelps, Elizabeth A

    2016-01-01

    Socially-conveyed rules and instructions strongly shape expectations and emotions. Yet most neuroscientific studies of learning consider reinforcement history alone, irrespective of knowledge acquired through other means. We examined fear conditioning and reversal in humans to test whether instructed knowledge modulates the neural mechanisms of feedback-driven learning. One group was informed about contingencies and reversals. A second group learned only from reinforcement. We combined quantitative models with functional magnetic resonance imaging and found that instructions induced dissociations in the neural systems of aversive learning. Responses in striatum and orbitofrontal cortex updated with instructions and correlated with prefrontal responses to instructions. Amygdala responses were influenced by reinforcement similarly in both groups and did not update with instructions. Results extend work on instructed reward learning and reveal novel dissociations that have not been observed with punishments or rewards. Findings support theories of specialized threat-detection and may have implications for fear maintenance in anxiety. PMID:27171199

  3. Gastrin-releasing peptide signaling plays a limited and subtle role in amygdala physiology and aversive memory.

    Directory of Open Access Journals (Sweden)

    Frederique Chaperon

    Full Text Available Links between synaptic plasticity in the lateral amygdala (LA and Pavlovian fear learning are well established. Neuropeptides including gastrin-releasing peptide (GRP can modulate LA function. GRP increases inhibition in the LA and mice lacking the GRP receptor (GRPR KO show more pronounced and persistent fear after single-trial associative learning. Here, we confirmed these initial findings and examined whether they extrapolate to more aspects of amygdala physiology and to other forms of aversive associative learning. GRP application in brain slices from wildtype but not GRPR KO mice increased spontaneous inhibitory activity in LA pyramidal neurons. In amygdala slices from GRPR KO mice, GRP did not increase inhibitory activity. In comparison to wildtype, short- but not long-term plasticity was increased in the cortico-lateral amygdala (LA pathway of GRPR KO amygdala slices, whereas no changes were detected in the thalamo-LA pathway. In addition, GRPR KO mice showed enhanced fear evoked by single-trial conditioning and reduced spontaneous firing of neurons in the central nucleus of the amygdala (CeA. Altogether, these results are consistent with a potentially important modulatory role of GRP/GRPR signaling in the amygdala. However, administration of GRP or the GRPR antagonist (D-Phe(6, Leu-NHEt(13, des-Met(14-Bombesin (6-14 did not affect amygdala LTP in brain slices, nor did they affect the expression of conditioned fear following intra-amygdala administration. GRPR KO mice also failed to show differences in fear expression and extinction after multiple-trial fear conditioning, and there were no differences in conditioned taste aversion or gustatory neophobia. Collectively, our data indicate that GRP/GRPR signaling modulates amygdala physiology in a paradigm-specific fashion that likely is insufficient to generate therapeutic effects across amygdala-dependent disorders.

  4. Food for song: expression of c-Fos and ZENK in the zebra finch song nuclei during food aversion learning.

    Directory of Open Access Journals (Sweden)

    Kirill Tokarev

    Full Text Available BACKGROUND: Specialized neural pathways, the song system, are required for acquiring, producing, and perceiving learned avian vocalizations. Birds that do not learn to produce their vocalizations lack telencephalic song system components. It is not known whether the song system forebrain regions are exclusively evolved for song or whether they also process information not related to song that might reflect their 'evolutionary history'. METHODOLOGY/PRINCIPAL FINDINGS: To address this question we monitored the induction of two immediate-early genes (IEGs c-Fos and ZENK in various regions of the song system in zebra finches (Taeniopygia guttata in response to an aversive food learning paradigm; this involves the association of a food item with a noxious stimulus that affects the oropharyngeal-esophageal cavity and tongue, causing subsequent avoidance of that food item. The motor response results in beak and head movements but not vocalizations. IEGs have been extensively used to map neuro-molecular correlates of song motor production and auditory processing. As previously reported, neurons in two pallial vocal motor regions, HVC and RA, expressed IEGs after singing. Surprisingly, c-Fos was induced equivalently also after food aversion learning in the absence of singing. The density of c-Fos positive neurons was significantly higher than that of birds in control conditions. This was not the case in two other pallial song nuclei important for vocal plasticity, LMAN and Area X, although singing did induce IEGs in these structures, as reported previously. CONCLUSIONS/SIGNIFICANCE: Our results are consistent with the possibility that some of the song nuclei may participate in non-vocal learning and the populations of neurons involved in the two tasks show partial overlap. These findings underscore the previously advanced notion that the specialized forebrain pre-motor nuclei controlling song evolved from circuits involved in behaviors related to feeding.

  5. Proton therapy

    International Nuclear Information System (INIS)

    Proton therapy has become a subject of considerable interest in the radiation oncology community and it is expected that there will be a substantial growth in proton treatment facilities during the next decade. I was asked to write a historical review of proton therapy based on my personal experiences, which have all occurred in the United States, so therefore I have a somewhat parochial point of view. Space requirements did not permit me to mention all of the existing proton therapy facilities or the names of all of those who have contributed to proton therapy. (review)

  6. Influence of stress on fear memory processes in an aversive differential conditioning paradigm in humans.

    Science.gov (United States)

    Bentz, Dorothée; Michael, Tanja; Wilhelm, Frank H; Hartmann, Francina R; Kunz, Sabrina; von Rohr, Isabelle R Rudolf; de Quervain, Dominique J-F

    2013-07-01

    It is widely assumed that learning and memory processes play an important role in the pathogenesis, expression, maintenance and therapy of anxiety disorders, such as phobias or post-traumatic stress disorder (PTSD). Memory retrieval is involved in symptom expression and maintenance of these disorders, while memory extinction is believed to be the underlying mechanism of behavioral exposure therapy of anxiety disorders. There is abundant evidence that stress and stress hormones can reduce memory retrieval of emotional information, whereas they enhance memory consolidation of extinction training. In this study we aimed at investigating if stress affects these memory processes in a fear conditioning paradigm in healthy human subjects. On day 1, fear memory was acquired through a standard differential fear conditioning procedure. On day 2 (24h after fear acquisition), participants either underwent a stressful cold pressor test (CPT) or a control condition, 20 min before memory retrieval testing and extinction training. Possible prolonged effects of the stress manipulation were investigated on day 3 (48 h after fear acquisition), when memory retrieval and extinction were tested again. On day 2, men in the stress group showed a robust cortisol response to stress and showed lower unconditioned stimulus (US) expectancy ratings than men in the control group. This reduction in fear memory retrieval was maintained on day 3. In women, who showed a significantly smaller cortisol response to stress than men, no stress effects on fear memory retrieval were observed. No group differences were observed with respect to extinction. In conclusion, the present study provides evidence that stress can reduce memory retrieval of conditioned fear in men. Our findings may contribute to the understanding of the effects of stress and glucocorticoids on fear symptoms in anxiety disorders and suggest that such effects may be sex-specific. PMID:23333200

  7. Gene therapy.

    OpenAIRE

    Mota Biosca, Anna

    1992-01-01

    Applications of gene therapy have been evaluated in virtually every oral tissue, and many of these have proved successful at least in animal models. While gene therapy will not be used routinely in the next decade, practitioners of oral medicine should be aware of the potential of this novel type of treatment that doubtless will benefit many patients with oral diseases.

  8. Lesions of the Lateral Habenula Increase Voluntary Ethanol Consumption and Operant Self-Administration, Block Yohimbine-Induced Reinstatement of Ethanol Seeking, and Attenuate Ethanol-Induced Conditioned Taste Aversion

    OpenAIRE

    Haack, Andrew K.; Sheth, Chandni; Schwager, Andrea L.; Sinclair, Michael S.; Tandon, Shashank; Taha, Sharif A.; ,

    2014-01-01

    The lateral habenula (LHb) plays an important role in learning driven by negative outcomes. Many drugs of abuse, including ethanol, have dose-dependent aversive effects that act to limit intake of the drug. However, the role of the LHb in regulating ethanol intake is unknown. In the present study, we compared voluntary ethanol consumption and self-administration, yohimbine-induced reinstatement of ethanol seeking, and ethanol-induced conditioned taste aversion in rats with sham or LHb lesions...

  9. New generalized poisson mixture model for bimodal count data with drug effect: An application to rodent brief‐access taste aversion experiments

    Science.gov (United States)

    Soto, J; Orlu Gul, M; Cortina‐Borja, M; Tuleu, C; Standing, JF

    2016-01-01

    Pharmacodynamic (PD) count data can exhibit bimodality and nonequidispersion complicating the inclusion of drug effect. The purpose of this study was to explore four different mixture distribution models for bimodal count data by including both drug effect and distribution truncation. An example dataset, which exhibited bimodal pattern, was from rodent brief‐access taste aversion (BATA) experiments to assess the bitterness of ascending concentrations of an aversive tasting drug. The two generalized Poisson mixture models performed the best and was flexible to explain both under and overdispersion. A sigmoid maximum effect (Emax) model with logistic transformation was introduced to link the drug effect to the data partition within each distribution. Predicted density‐histogram plot is suggested as a model evaluation tool due to its capability to directly compare the model predicted density with the histogram from raw data. The modeling approach presented here could form a useful strategy for modeling similar count data types. PMID:27472892

  10. Application of a general risk management model to portfolio optimization problems with elliptical distributed returns for risk neutral and risk averse decision makers.

    OpenAIRE

    Kaynar, B.; Birbil, Ilker; Frenk, Hans

    2007-01-01

    textabstractWe discuss a class of risk measures for portfolio optimization with linear loss functions, where the random returns of financial instruments have a multivariate elliptical distribution. Under this setting we pay special attention to two risk measures, Value-at-Risk and Conditional-Value-at-Risk and differentiate between risk neutral and risk averse decision makers. When the so-called disutility function is taken as the identity function, the optimization problem is solved for a ri...

  11. Individual Variation in the Propensity to Attribute Incentive Salience to an Appetitive Cue Predicts the Propensity to Attribute Motivational Salience to an Aversive Cue

    OpenAIRE

    Morrow, Jonathan D.; Maren, Stephen; ROBINSON, TERRY E.

    2011-01-01

    It has been proposed that animals that attribute high levels of incentive salience to reward-related cues may be especially vulnerable to addiction. Individual variation has also been observed in the motivational value attributed to aversive cues, which may confer vulnerability to anxiety disorders such as post-traumatic stress disorder (PTSD). There may be a core behavioral trait that contributes to individual variation in the motivational value assigned to predictive cues regardless of emot...

  12. Do US policy uncertainty, leveraging costs and global risk aversion impact emerging market equities? An application of bounds testing approach to the BRICS

    OpenAIRE

    Momin, Ebaad; Masih, Mansur

    2015-01-01

    ‘When the United States sneezes, the world catches a cold. And when America recovers, the planet has a spring in its step’ – For decades together, this metaphor has seemed an accurate description of the global economy. Through this paper we have tried to examine the short and long term dependence structure between the stock markets of emerging markets and influential global factors (US economic policy uncertainty, the global risk aversion and the cheap borrowing costs in t...

  13. Fear memory formation can affect a different memory: fear conditioning affects the extinction, but not retrieval, of conditioned taste aversion (CTA) memory

    OpenAIRE

    Joels, Gil; Lamprecht, Raphael

    2014-01-01

    The formation of fear memory to a specific stimulus leads to subsequent fearful response to that stimulus. However, it is not apparent whether the formation of fear memory can affect other memories. We study whether specific fearful experience leading to fear memory affects different memories formation and extinction. We revealed that cued fear conditioning, but not unpaired or naïve training, inhibited the extinction of conditioned taste aversion (CTA) memory that was formed after fear condi...

  14. Sex differences between CRF1 receptor deficient mice following naloxone-precipitated morphine withdrawal in a conditioned place aversion paradigm: implication of HPA axis.

    Directory of Open Access Journals (Sweden)

    Juan-Antonio García-Carmona

    Full Text Available Extinction period of positive affective memory of drug taking and negative affective memory of drug withdrawal, as well as the different response of men and women might be important for the clinical treatment of drug addiction. We investigate the role of corticotropin releasing factor receptor type one (CRF1R and the different response of male and female mice in the expression and extinction of the aversive memory.We used genetically engineered male and female mice lacking functional CRF1R. The animals were rendered dependent on morphine by intraperitoneally injection of increasing doses of morphine (10-60 mg/kg. Negative state associated with naloxone (1 mg/kg s.c.-precipitated morphine withdrawal was examined by using conditioned place aversion (CPA paradigm. No sex differences for CPA expression were found in wild-type (n = 29 or CRF1R knockout (KO mice (n = 29. However, CRF1R KO mice presented less aversion score than wild-type mice, suggesting that CRF1R KO mice were less responsive than wild-type to continuous associations between drug administration and environmental stimuli. In addition, CPA extinction was delayed in wild-type and CRF1R KO male mice compared with females of both genotypes. The genetic disruption of the CRF1R pathway decreased the period of extinction in males and females suggesting that CRF/CRF1R is implicated in the duration of aversive memory. Our results also showed that the increase in adrenocorticotropic hormone (ACTH levels observed in wild-type (n = 11 mice after CPA expression, were attenuated in CRF1R KO mice (n = 10. In addition, ACTH returned to the baseline levels in males and females once CPA extinction was finished.These results suggest that, at least, CPA expression is partially due to an increase in plasma ACTH levels, through activation of CRF1R, which can return when CPA extinction is finished.

  15. Juvenile hormone enhances aversive learning performance in 2-day old worker honey bees while reducing their attraction to queen mandibular pheromone.

    Science.gov (United States)

    McQuillan, H James; Nakagawa, Shinichi; Mercer, Alison R

    2014-01-01

    Previous studies have shown that exposing young worker bees (Apis mellifera) to queen mandibular pheromone (QMP) reduces their aversive learning performance, while enhancing their attraction to QMP. As QMP has been found to reduce the rate of juvenile hormone (JH) synthesis in worker bees, we examined whether aversive learning in 2-day old workers exposed to QMP from the time of adult emergence could be improved by injecting JH (10 µg in a 2 µl volume) into the haemolymph. We examined in addition, the effects of JH treatment on worker attraction to QMP, and on the levels of expression of amine receptor genes in the antennae, as well as in the mushroom bodies of the brain. We found that memory acquisition and 1-hour memory recall were enhanced by JH. In contrast, JH treatment reduced the bees' attraction towards a synthetic strip impregnated with QMP (Bee Boost). Levels of expression of the dopamine receptor gene Amdop1 were significantly lower in the mushroom bodies of JH-treated bees than in bees treated with vehicle alone (acetone diluted with bee ringer). Expression of the octopamine receptor gene, Amoa1, in this brain region was also affected by JH treatment, and in the antennae, Amoa1 transcript levels were significantly lower in JH-treated bees compared to controls. The results of this study suggest that QMP's effects on JH synthesis may contribute to reducing aversive learning performance and enhancing attraction to QMP in young worker bees. PMID:25390885

  16. Physical Therapy and Occupational Therapy in Progeria

    Science.gov (United States)

    Physical Therapy and Occupational Therapy in Progeria Information for Families and Caretakers from The Progeria Research Foundation Written ... accelerated aging in children. Children with Progeria need Physical Therapy (PT) and Occupational Therapy (OT) as often as ...

  17. The role of the glucocorticoid receptor gene (NR3C1) for the processing of aversive stimuli.

    Science.gov (United States)

    Schneider, Katja Kerstin; Frings, Christian; Meyer, Jobst; Schote, Andrea B

    2016-06-01

    The glucocorticoid receptor (GR) is a crucial component of the hypothalamus-pituitary-adrenal (HPA) axis and as such a part of the stress response system. An impairment of the GR not only alters the level of glucocorticoids, but also modulates cognitive functions and the processing of emotional stimuli. We tested the effects of functional polymorphisms of the GR-encoding gene (NR3C1) on the processing of emotional stimuli on a basal level. In a sample of n=182 participants, we found a haplotype (NR3C1-CTGGACA) to modulate the performance in an emotional reaction time task. Compared to non-carriers, participants who carried the haplotype were quicker to react after aversive stimuli had been presented. In contrast, the presence of the haplotype had no effect on the processing of neutral stimuli. We conclude that properties of the glucocorticoid receptor contribute to the processing of emotional stimuli and influence the intensity of their processing even in the absence of acute stressors. PMID:26689331

  18. Withania somnifera Dunal (Indian ginseng) impairs acquisition and expression of ethanol-elicited conditioned place preference and conditioned place aversion.

    Science.gov (United States)

    Spina, Liliana; Longoni, Rosanna; Rosas, Michela; Collu, Maria; Peana, Alessandra T; Espa, Elena; Kasture, Sanjay; Cotti, Elisabetta; Acquas, Elio

    2015-11-01

    Withania somnifera Dunal (Indian Ginseng) has recently been shown to impair ethanol self-administration. In order to gain further insights on the ability of the Withania somnifera standardised root extract (WSE) to affect the motivational properties of ethanol, this study investigated whether WSE may also affect ethanol (2 g/kg)-elicited conditioned place preference (CPP) and aversion (CPA). To this end male CD-1 mice were conditioned under two distinct schedules: in backward conditioning experiments ethanol was administered before mice were placed in the conditioning apparatus (CPP) while, in forward conditioning experiments, ethanol was administered immediately after removing mice from the apparatus (CPA). Following these schedules, mice developed significant CPP and CPA, respectively. Administration of WSE significantly impaired both the acquisition (50 and 100 mg/kg) and the expression (50 mg/kg) of CPP and CPA without affecting spatial memory (50 mg/kg), as determined by a two-trial memory recognition task. Overall, the study highlights the ability of WSE to interfere with both positive and negative motivational properties of ethanol and suggests that the effects of WSE may target both ethanol's motivational properties and underpinning associative learning mechanisms. In conclusion, these results cast new light on Withania somnifera as an agent potentially useful to counteract distinct aspects of ethanol effects. PMID:26349555

  19. Aversive Behavior in the Nematode C. elegans Is Modulated by cGMP and a Neuronal Gap Junction Network.

    Science.gov (United States)

    Krzyzanowski, Michelle C; Woldemariam, Sarah; Wood, Jordan F; Chaubey, Aditi H; Brueggemann, Chantal; Bowitch, Alexander; Bethke, Mary; L'Etoile, Noelle D; Ferkey, Denise M

    2016-07-01

    All animals rely on their ability to sense and respond to their environment to survive. However, the suitability of a behavioral response is context-dependent, and must reflect both an animal's life history and its present internal state. Based on the integration of these variables, an animal's needs can be prioritized to optimize survival strategies. Nociceptive sensory systems detect harmful stimuli and allow for the initiation of protective behavioral responses. The polymodal ASH sensory neurons are the primary nociceptors in C. elegans. We show here that the guanylyl cyclase ODR-1 functions non-cell-autonomously to downregulate ASH-mediated aversive behaviors and that ectopic cGMP generation in ASH is sufficient to dampen ASH sensitivity. We define a gap junction neural network that regulates nociception and propose that decentralized regulation of ASH signaling can allow for rapid correlation between an animal's internal state and its behavioral output, lending modulatory flexibility to this hard-wired nociceptive neural circuit. PMID:27459302

  20. Aversive viscerally referred states and thirst accompanying the sating of hunger motivation by rapid digestion of glucosaccharides.

    Science.gov (United States)

    Booth, David A; O'Leary, Gemma; Li, Lixiang; Higgs, Suzanne

    2011-03-01

    Associative conditioning of satiety indicates that concentrated maltodextrin (cMD) may induce a mildly aversive visceral signal within 20 min of its ingestion, as well as satiating normally. Individuals' awareness of this adverse state was tested on ratings of statistically distinct descriptions of factors liable to suppress hunger, whether distressing or comfortably satisfying. Wanted amount of a food and the pleasantness of eating it correlated highly for each of five foods, once again refuting the widespread presumption that "pleasant" refers to sensory pleasure; hence, as in previous reports, suppression of hunger was measured as a reduction of the averaged pleasantness of functionally related foods. At 20 min after the start of ingestion of a small meal on a near-empty stomach, cMD reliably reduced hunger. The greatest influence on hunger, besides normal sating, was thirst, but there were also tendencies to nausea and bloat, although all less than after a full sized meal. Visceral processes shortly after a meal can create dissociable conscious states, only one of which is satiety for food. PMID:21118700

  1. Amygdala recruitment in schizophrenia in response to aversive emotional material: a meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Anticevic, Alan; Van Snellenberg, Jared X; Cohen, Rachel E; Repovs, Grega; Dowd, Erin C; Barch, Deanna M

    2012-05-01

    Emotional dysfunction has long been established as a critical clinical feature of schizophrenia. In the past decade, there has been extensive work examining the potential contribution of abnormal amygdala activation to this dysfunction in patients with schizophrenia. A number of studies have demonstrated under-recruitment of the amygdala in response to emotional stimuli, while others have shown intact recruitment of this region. To date, there have been few attempts to synthesize this literature using quantitative criteria or to use a formal meta-analytic approach to examine which variables may moderate the magnitude of between-group differences in amygdala activation in response to aversive emotional stimuli. We conducted a meta-analysis of amygdala activation in patients with schizophrenia, using a bootstrapping approach to investigate: (a) evidence for amygdala under-recruitment in schizophrenia and (b) variables that may moderate the magnitude of between-group differences in amygdala activation. We demonstrate that patients with schizophrenia show statistically significant, but modest, under-recruitment of bilateral amygdala (mean effect size = -0.20 SD). However, present findings indicate that this under-recruitment is dependent on the use of a neutral vs emotion interaction contrast and is not apparent if amygdala activation by patients and controls is evaluated in a negative emotional condition only. PMID:21123853

  2. Instructed knowledge shapes feedback-driven aversive learning in striatum and orbitofrontal cortex, but not the amygdala

    Science.gov (United States)

    Atlas, Lauren Y; Doll, Bradley B; Li, Jian; Daw, Nathaniel D; Phelps, Elizabeth A

    2016-01-01

    Socially-conveyed rules and instructions strongly shape expectations and emotions. Yet most neuroscientific studies of learning consider reinforcement history alone, irrespective of knowledge acquired through other means. We examined fear conditioning and reversal in humans to test whether instructed knowledge modulates the neural mechanisms of feedback-driven learning. One group was informed about contingencies and reversals. A second group learned only from reinforcement. We combined quantitative models with functional magnetic resonance imaging and found that instructions induced dissociations in the neural systems of aversive learning. Responses in striatum and orbitofrontal cortex updated with instructions and correlated with prefrontal responses to instructions. Amygdala responses were influenced by reinforcement similarly in both groups and did not update with instructions. Results extend work on instructed reward learning and reveal novel dissociations that have not been observed with punishments or rewards. Findings support theories of specialized threat-detection and may have implications for fear maintenance in anxiety. DOI: http://dx.doi.org/10.7554/eLife.15192.001 PMID:27171199

  3. Oxygen Therapy

    Science.gov (United States)

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body needs to function. Normally, your lungs absorb oxygen from the air you breathe. But some conditions ...

  4. Oxygen Therapy

    Science.gov (United States)

    ... therapy works, it helps to understand how your respiratory system works. This system is a group of organs and tissues that help you breathe. The respiratory system includes the airways and lungs. The airways carry ...

  5. Maintenance Therapy in IBD

    Science.gov (United States)

    ... Help Center Home > Resources > Maintenance Therapy Go Back Maintenance Therapy Email Print + Share The term "maintenance therapy" ... are referred to as "maintenance therapies." Why is Maintenance Therapy Needed in IBD? Both Crohn's disease and ...

  6. Visceral Blood Flow Modulation: Potential Therapy for Morbid Obesity

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Tyler J., E-mail: tjharris@gmail.com [University of California, Los Angeles, Department of Vascular and Interventional Radiology (United States); Murphy, Timothy P.; Jay, Bryan S. [Rhode Island Hospital, Brown University, Department of Diagnostic Imaging, Vascular Disease Research Center (United States); Hampson, Christopher O.; Zafar, Abdul M. [University of Texas Health Science Center at San Antonio, Department of Radiology (United States)

    2013-06-15

    We present this preliminary investigation into the safety and feasibility of endovascular therapy for morbid obesity in a swine model. A flow-limiting, balloon-expandable covered stent was placed in the superior mesenteric artery of three Yorkshire swine after femoral arterial cutdown. The pigs were monitored for between 15 and 51 days after the procedure and then killed, with weights obtained at 2-week increments. In the two pigs in which the stent was flow limiting, a reduced rate of weight gain (0.42 and 0.53 kg/day) was observed relative to the third pig (0.69 kg/day), associated with temporary food aversion and signs of mesenteric ischemia in one pig.

  7. Visceral Blood Flow Modulation: Potential Therapy for Morbid Obesity

    International Nuclear Information System (INIS)

    We present this preliminary investigation into the safety and feasibility of endovascular therapy for morbid obesity in a swine model. A flow-limiting, balloon-expandable covered stent was placed in the superior mesenteric artery of three Yorkshire swine after femoral arterial cutdown. The pigs were monitored for between 15 and 51 days after the procedure and then killed, with weights obtained at 2-week increments. In the two pigs in which the stent was flow limiting, a reduced rate of weight gain (0.42 and 0.53 kg/day) was observed relative to the third pig (0.69 kg/day), associated with temporary food aversion and signs of mesenteric ischemia in one pig.

  8. Family therapy

    Directory of Open Access Journals (Sweden)

    Shaikh Altamash

    2013-01-01

    Full Text Available Another major force not letting us succeed in the treatment of diabetes remains right inside the patients home, their family members. Hence, it is important to know the perception of the close family members about this simple and strong tool in diabetes, ′insulin′. The drug is nearing its century, it has not fully being accepted gracefully even in todays electronic savvy society. So, we need to strongly discover the reason for its non-acceptance, while trials are out inventing new drugs. One vital thing that can change this attitude is increasing the understanding of this drug, insulin in depth to close people around the patient, the ′family′. Underestimating family′s perception about disease and treatment for diabetes is detrimental to both diseased and the doctor. This consists of a biopsychosocial model; biological, psychological and social factors. Family forms the most important part of it. The strategies in family therapy include psychodynamic, structural, strategic, and cognitive-behavioral component. Diabetes has and will continue to rise, so will be the treatment options. From the clinicians side its to fix fasting first but from patients its fix family first. Family therapy demonstrates the importance of insulin initiation and maintenance in insulin naive patients, and continuation for others. The specific needs of such patients and their impact on family life are met with family therapy. Who needs family therapy? Benefits of family therapy and a case based approach is covered.

  9. Music therapy

    DEFF Research Database (Denmark)

    Ridder, Hanne Mette Ochsner

    alternate with clear and lucid mental states. These states are important as it is here that it is possible to meet the person’s psychosocial needs. Ketil Normann’s conceps of periods of lucidity are presented and connected to clinical music therapy practice and how it is possible to use music in order...... as a consequence of person-centred care. Umeå University Medical Dissertations. New Series. Ridder, H.M. (2005). Music therapy as a way to enhance lucidity in persons with dementia in advanced stages. In: Esch, A.; Frohne-Hagemann, I.; Laqua, M.; Schirmer, H.; Seitz, E. (Eds.) Jahrbuch Musicktherapie. Forschung...... und Entwicklung Music Therapy Annual. Research and Development. 2005 (1), pp. 25-40. Reichert Verlag Wiesbaden....

  10. Art Therapy

    DEFF Research Database (Denmark)

    Skov, Vibeke; Pedersen, Inge Nygaard

    2014-01-01

    Abstract Based on a Jungian approach, this article will introduce an integrative model to therapeutic change using art therapy methods as practical tools, with the aim of improving quality of life and in the prevention of depression. In a research study involving six participants, painting, clay...... work and drumming were used together with imagination and personal dialogues linked to the artwork. These art therapy processes attempted to combine the participant’s experience of inner and outer reality. The effect of gaining more knowledge about their inner reality using dreams and symbols......, was that participants gained a new understanding about their personal life. In addition, some participants were able to continue to use art therapy experiences as selfdevelopmental tools after the research study terminated. Jung’s description of the interactive relationship between the two living parts of the psyche...

  11. Failure to produce taste-aversion learning in rats exposed to static electric fields and air ions

    Energy Technology Data Exchange (ETDEWEB)

    Creim, J.A.; Lovely, R.H.; Weigel, R.J.; Forsythe, W.C.; Anderson, L.E. [Pacific Northwest Labs., Richland, WA (United States)

    1995-12-01

    Taste-aversion (TA) learning was measured to determine whether exposure to high-voltage direct current (HVdc) static electric fields can produce TA learning in male Long Evans rats. Fifty-six rats were randomly distributed into four groups of 14 rats each. All rats were placed on a 20 min/day drinking schedule for 12 consecutive days prior to receiving five conditioning trials. During the conditioning trials, access to 0.1% sodium saccharin-flavored water was given for 20 min, followed 30 min later by one of four treatments. Two groups of 14 rats each were individually exposed to static electric fields and air ions, one group to +75 kV/m (+2 {times} 10{sup 5} air ions/cm{sup 3}) and the other group to {minus}75 kV/m ({minus}2 {times} 10{sup 5} air ions/cm{sup 3}). Two other groups of 14 rats each served as sham-exposed controls, with the following variation in one of the sham-exposed groups: this group was subdivided into two subsets of seven rats each, so that a positive control group could be included to validate the experimental design. The positive control group (n = 7) was injected with cyclophosphamide 25 mg/kg, i.p., 30 min after access to saccharin-flavored water on conditioning days, whereas the other subset of seven rats was similarly injected with an equivalent volume of saline. Access to saccharin-flavored water on conditioning days was followed by the treatments described above and was alternated daily with water recovery sessions in which the rats received access to water for 20 min in the home cage without further treatment. Following the last water-recovery session, a 20 min, two-bottle preference test (between water and saccharin-flavored water) was administered to each group. The positive control group did show TA learning, thus validating the experimental protocol.

  12. Bilateral lesions in a specific subregion of posterior insular cortex impair conditioned taste aversion expression in rats.

    Science.gov (United States)

    Schier, Lindsey A; Blonde, Ginger D; Spector, Alan C

    2016-01-01

    The gustatory cortex (GC) is widely regarded for its integral role in the acquisition and retention of conditioned taste aversions (CTAs) in rodents, but large lesions in this area do not always result in CTA impairment. Recently, using a new lesion mapping system, we found that severe CTA expression deficits were associated with damage to a critical zone that included the posterior half of GC in addition to the insular cortex (IC) that is just dorsal and caudal to this region (visceral cortex). Lesions in anterior GC were without effect. Here, neurotoxic bilateral lesions were placed in the anterior half of this critical damage zone, at the confluence of the posterior GC and the anterior visceral cortex (termed IC2 ), the posterior half of this critical damage zone that contains just VC (termed IC3), or both of these subregions (IC2 + IC3). Then, pre- and postsurgically acquired CTAs (to 0.1 M NaCl and 0.1 M sucrose, respectively) were assessed postsurgically in 15-minute one-bottle and 96-hour two-bottle tests. Li-injected rats with histologically confirmed bilateral lesions in IC2 exhibited the most severe CTA deficits, whereas those with bilateral lesions in IC3 were relatively normal, exhibiting transient disruptions in the one-bottle sessions. Groupwise lesion maps showed that CTA-impaired rats had more extensive damage to IC2 than did unimpaired rats. Some individual differences in CTA expression among rats with similar lesion profiles were observed, suggesting idiosyncrasies in the topographic representation of information in the IC. Nevertheless, this study implicates IC2 as the critical zone of the IC for normal CTA expression. PMID:26053891

  13. What Is Music Therapy?

    Science.gov (United States)

    American Music Therapy Association Home Contact News Help/FAQ Members Only Login About Music Therapy & AMTA What is Music Therapy? Definition and Quotes ... is Music Therapy? Print Email Share What is Music Therapy What is Music Therapy? Music Therapy is the ...

  14. Dance Therapy.

    Science.gov (United States)

    Leventhal, Marcia B.

    1980-01-01

    Dance therapy deals with personal growth via body-mind interaction. A change in movement expression is believed to result in a personality or behavior change. The therapist is trained to become sensitive to movement expression as it relates to the psychological, motor, and cognitive development of the child. (JN)

  15. Delay aversion but preference for large and rare rewards in two choice tasks: implications for the measurement of self-control parameters

    Directory of Open Access Journals (Sweden)

    Laviola Giovanni

    2006-06-01

    Full Text Available Abstract Background Impulsivity is defined as intolerance/aversion to waiting for reward. In intolerance-to-delay (ID protocols, animals must choose between small/soon (SS versus large/late (LL rewards. In the probabilistic discount (PD protocols, animals are faced with choice between small/sure (SS versus large/luck-linked (LLL rewards. It has been suggested that PD protocols also measure impulsivity, however, a clear dissociation has been reported between delay and probability discounting. Results Wistar adolescent rats (30- to 46-day-old were tested using either protocol in drug-free state. In the ID protocol, animals showed a marked shift from LL to SS reward when delay increased, and this despite adverse consequences on the total amount of food obtained. In the PD protocol, animals developed a stable preference for LLL reward, and maintained it even when SS and LLL options were predicted and demonstrated to become indifferent. We demonstrate a clear dissociation between these two protocols. In the ID task, the aversion to delay was anti-economical and reflected impulsivity. In the PD task, preference for large reward was maintained despite its uncertain delivery, suggesting a strong attraction for unitary rewards of great magnitude. Conclusion Uncertain delivery generated no aversion, when compared to delays producing an equivalent level of large-reward rarefaction. The PD task is suggested not to reflect impulsive behavior, and to generate patterns of choice that rather resemble the features of gambling. In summary, present data do indicate the need to interpret choice behavior in ID and PD protocols differently.

  16. Research on closed-loop supply chain network equilibrium with two-type suppliers, risk-averse manufacturers and capacity constraints

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2015-04-01

    Full Text Available Purpose: the aim of this paper is to investigate the closed-loop supply chain (CLSC network equilibrium wiht the consideration of three practical factors: two complementary types of suppliers, risk-averse character of the manufacturer and capacity constraints of the suppliers. Design/methodology/approach: The equilibrium of various decision makers including the suppliers, the manufacturers, the retailers, the collectors and the demand markets are modeled via finite-dimensional variational inequality, respectively. Then the governing CLSC network equilibrium model is established. The logarithmic-quadratic proximal prediction-correction algorithm is designed to solve the variational inequality model. Numerical examples are given to analyze the impact of return rate, risk-averse degree and capacity constraints on the network equilibrium under different product BOMs. Findings: with the increase of return rate, the profits of various channel members and the performance of the CLSC system will improve. There is a contradiction between profit maximization and risk minimization for the manufacturers. Moreover, the economic behavior of the CLSC is likely to be limited by the capacity constraints of the suppliers. Originality/value: Prior to this paper, few papers have addressed with the CLSC network equilibrium considering some practical factors. They assume all the suppliers are identical and all the decision-makers are risk neutral. Furthermore, the production capacities of all suppliers are assumed to be infinite or large enough. To fill the gap, this paper examines the influences of two-type suppliers, risk aversion and capacity constraints upon the CLSC network equilibrium.

  17. Hadron therapy

    International Nuclear Information System (INIS)

    Full text: Historically discoveries and technological advances in radiation and accelerator physics have been rapidly applied in the healing arts. X rays, discovered by Roentgen in 1895, and radioisotopes, discovered by Becquerel in 1896, were both applied to the treatment of cancer by the first year of the twentieth century. By the time that Chadwick discovered the neutron in 1932 radiotherapy was a well-established modality for the treatment of cancer. The potential use of neutrons in radiotherapy was immediately recognized by L.H. Gray (a recent Ph.D. graduate from the Cavendish laboratories in Cambridge). He built a neutron generator for radiobiology research at Mount Vernon Hospital in London, it's design was based on a similar device built at Cambridge by Mark Oliphant. In parallel with these developments Earnest Lawrence, in collaboration with his brother John Lawrence, a physician, were also studying the radiobiology of neutrons. They obtained some funding from the US National Cancer Institute to construct a 60'' cyclotron for neutron radiation therapy. These clinical trials, started in 1938, were the first application of heavy particles for cancer therapy. Immediately after the second World War advances in accelerator technology lead to the building of the first synchrocyclotrons, which produced proton beams with ranges approaching 30 cm in water. At the Harvard synchrocyclotron Robert R. Wilson realized that proton beams might have considerable advantages over other radiation beams in the treatment of deep-seated tumors. This advantage derives from the increase in stopping power at the end of the proton range, first observed by W.H.Bragg at the University of Adelaide; a phenomenon now known as the Bragg peak. Conventional X-ray beams are exponentially attenuated by matter and, hence, delivering large radiation doses to tumors at depth while not causing excessive damage to the overlying normal tissues can be problematical. The Bragg peak and the well

  18. Anecdotal therapies.

    Science.gov (United States)

    Millikan, L E

    1999-01-01

    Traditionally, many advances in medicine have been serendipitous. Are serendipitous and anecdotal synonymous? Many of our materia medica today relate to initial probes and anecdotal reports that matured to full investigation and therapeutic indications. The recent situation regarding Skin Cap is one that highlights the downside of this scenario. Several drugs in the US continue usage largely related to anecdotal indications, and anecdotal extension of legend indications is a standard for American Dermatology. The situation with systemic drugs, such as Trental, zinc preparations, imidazoles for extended indications, lysine and melatonin, all will be discussed. Topical preparations such as skin cap, cantharone, Vioform, all also are included in this category. It is important to place this topic in perspective in regards to geographic variation and therapeutic need. Many diseases lacking specific therapy are important targets for anecdotal therapy, and this will foster continued approaches in this area. The growing standardization of medicine and pharmaceutical regulation, threatens the anecdotal approach, but it provides still an important link to the future for some forms of therapy in diseases that are difficult to treat. Traditionally, the anecdote has been the first step in the therapeutic chain. Withering discovery of the benefits of the common fox glove in dropsy, was followed by many other anecdotes arriving via folk-medicine in the New World. This approach of utilizing folk medicine has now reached new heights, with very active searches by major pharmaceutical companies throughout the third world for remedies that may have potential. Couched with this is the history of anecdotal "snake-oil" remedies, that clearly had no benefit to anyone except the huckster marketing same. The excesses in this area of unproven and false therapies, led to the gradual organization of therapeutic trials and the Food and Drug Administration in the US as we know it today. The

  19. Music Therapy

    DEFF Research Database (Denmark)

    Sanfi, Ilan

    2012-01-01

    may cause detrimental long-term effects. Three studies have examined the effect of music therapy procedural support (MTPS) under needle procedures. Consequently, this study aims at examining the effects of MTPS in an RCT. Moreover, the study addresses clinical aspects of the applied MT intervention...... and provides research-based clinical tools. Methods 41 children (1 to 10 years) were enrolled and underwent a single PIVA procedure. The children were randomly assigned to either an MT or a comparable control group receiving PIVA. In addition, the music therapy (MT) group received individualised MTPS (i.......e. music alternate engagement) before, during, and after PIVA. The intervention was performed by a trained music therapist and comprised preferred songs, improvised songs/music, and instrument playing. The study was carried out in accordance with the rules in force regarding research ethics and clinical MT...

  20. Music Therapy

    DEFF Research Database (Denmark)

    Trondalen, Gro; Bonde, Lars Ole

    2012-01-01

    Music therapy (MT) is most commonly defined as an intervention where “the therapist helps the client to promote health, using music experiences and the relationships developing through them” (Bruscia 1998). Also other definitions of MT agree that a therapeutic relationship is important for a music...... intervention to be considered MT. Other interventions that “use music for health-related goals, but in ways that do not qualify as music therapy” (Gold 2009), may be described as music medicine, or simply as music listening. In this text we elaborate on an overview chapter covering some of the different major...... music therapy orientations/models (Guided Imagery and Music, Nordoff-Robbins, Psychoanalytic, Cognitive-behavioral etc), their theoretical foundations and their practical approaches to health and wellbeing or ‘health musicking’. The relational context – the interplay of (expressive as well as receptive...