Aversive Effects Research Articles

A central limit theorem, loss aversion and multi-armed bandits

This paper studies a multi-armed bandit problem where the decision-maker is loss averse, in particular she is risk averse in the domain of gains and risk loving in the domain of losses. The focus is on large horizons. Consequences of loss aversion for asymptotic (large horizon) properties are derived in a number of analytical results. The analysis is based on a new central limit theorem for a set of measures under which conditional variances can vary in a largely unstructured history-dependent way subject only to the restriction that they lie in a fixed interval.

Effects of predator associative learning and innate aversion on mimicry complexes

Effects of predator associative learning and innate aversion on mimicry complexes

Striatal hypoactivation during monetary loss anticipation in individuals with substance use disorders in a heterogenous urban American Indian sample

Research suggests that disproportionate exposure to risk factors places American Indian (AI) peoples at higher risk for substance use disorders (SUD). Although SUD is linked to striatal prioritization of drug rewards over other appetitive stimuli, there are gaps in the literature related to the investigation of aversive valuation processing, and inclusion of AI samples. To address these gaps, this study compared striatal anticipatory gain and loss processing between AI-identified with SUD (SUD+; n = 52) and without SUD (SUD-; n = 35) groups from the Tulsa 1000 study who completed a monetary incentive delay (MID) task during functional magnetic resonance imaging. Results indicated that striatal activations in the nucleus accumbens (NAcc), caudate, and putamen were greatest for anticipating gains (ps < 0.001) but showed no group differences. In contrast to gains, the SUD+ exhibited lower NAcc (p = .01, d =0.53) and putamen (p = .04, d =0.40) activation to anticipating large losses than the comparison group. Within SUD+ , lower striatal responses during loss anticipations were associated with slower MID reaction times (NAcc: r = −0.43; putamen: r = −0.35) during loss trials. This is among the first imaging studies to examine underlying neural mechanisms associated with SUD within AIs. Attenuated loss processing provides initial evidence of a potential mechanism wherein blunted prediction of aversive consequences may be a defining feature of SUD that can inform future prevention and intervention targets.

Impact of the gut microbiome on nicotine's motivational effects and glial cells in the ventral tegmental area in male mice.

A link between gut dysbiosis and the pathogenesis of brain disorders has been identified. A role for gut bacteria in drug reward and addiction has been suggested but very few studies have investigated their impact on brain and behavioral responses to addictive drugs so far. In particular, their influence on nicotine's addiction-like processes remains unknown. In addition, evidence shows that glial cells shape the neuronal activity of the mesolimbic system but their regulation, within this system, by the gut microbiome is not established. We demonstrate that a lack of gut microbiota in male mice potentiates the nicotine-induced activation of sub-regions of the mesolimbic system. We further show that gut microbiota depletion enhances the response to nicotine of dopaminergic neurons of the posterior ventral tegmental area (pVTA), and alters nicotine's rewarding and aversive effects in an intra-VTA self-administration procedure. These effects were not associated with gross behavioral alterations and the nicotine withdrawal syndrome was not impacted. We further show that depletion of the gut microbiome modulates the glial cells of the mesolimbic system. Notably, it increases the number of astrocytes selectively in the pVTA, and the expression of postsynaptic density protein 95 in both VTA sub-regions, without altering the density of the astrocytic glutamatergic transporter GLT1. Finally, we identify several sub-populations of microglia in the VTA that differ between its anterior and posterior sub-parts, and show that they are re-organized in conditions of gut microbiota depletion. The present study paves the way for refining our understanding of the pathophysiology of nicotine addiction.

Cyanidin prevents MDPV withdrawal-induced anxiety-like effects and dysregulation of cytokine systems in rats

Psychostimulant exposure and withdrawal cause neuroimmune dysregulation and anxiety that contributes to dependence and relapse. Here, we tested the hypothesis that withdrawal from the synthetic cathinone MDPV (methylenedioxypyrovalerone) produces anxiety-like effects and enhanced levels of mesocorticolimbic cytokines that are inhibited by cyanidin, an anti-inflammatory flavonoid and nonselective blocker of IL-17A signaling. For comparison, we tested effects on glutamate transporter systems that are also dysregulated during psychostimulant free period. Rats injected for 9 d with MDPV (1 mg/kg, IP) or saline were pretreated daily with cyanidin (0.5 mg/kg, IP) or saline, followed by behavioral testing on the elevated zero maze (EZM) 72 h after the last MDPV injection. MDPV withdrawal caused a reduction in time spent on the open arm of the EZM that was prevented by cyanidin. Cyanidin itself did not affect locomotor activity or time spent on the open arm, or cause aversive or rewarding effects in place preference experiments. MDPV withdrawal caused enhancement of cytokine levels (IL-17A, IL-1β, IL-6, TNF=α, IL-10, and CCL2) in the ventral tegmental area, but not amygdala, nucleus accumbens, or prefrontal cortex, that was prevented by cyanidin. During MDPV withdrawal, mRNA levels of glutamate aspartate transporter (GLAST) and glutamate transporter subtype 1 (GLT-1) in the amygdala were also elevated but normalized by cyanidin treatment. These results show that MDPV withdrawal induced anxiety, and brain-region specific dysregulation of cytokine and glutamate systems, that are both prevented by cyanidin, thus identifying cyanidin for further investigation in the context of psychostimulant dependence and relapse.

Bridging the Gap Between Believing and Memory Functions.

Believing has recently been recognized as a fundamental brain function linking a person's experience with his or her attitude, actions and predictions. In general, believing results from the integration of ambient information with emotions and can be reinforced or modulated in a probabilistic fashion by new experiences. Although these processes occur in the subliminal realm, humans can become aware of what they believe and express it verbally. We explain how believing is interwoven with memory functions in a multifaceted fashion. Linking the typically rapid and adequate reactions of a subject to what he/she believes is enabled by working memory. Perceptions are stored in episodic memory as beneficial or aversive events, while the corresponding verbal descriptions of what somebody believes are stored in semantic memory. After recall from memory of what someone believes, personally relevant information can be communicated to other people. Thus, memory is essential for maintaining what people believe.

A partner's smile is not per se a safety signal: Psychophysiological response patterns to instructed threat and safety.

Recent studies on fear conditioning and pain perception suggest that pictures of loved ones (e.g., a romantic partner) may serve as a prepared safety cue that is less likely to signal aversive events. Challenging this view, we examined whether pictures of smiling or angry loved ones are better safety or threat cues. To this end, 47 healthy participants were verbally instructed that specific facial expressions (e.g., happy faces) cue threat of electric shocks and others cue safety (e.g., angry faces). When facial images served as threat cues, they elicited distinct psychophysiological defensive responses (e.g., increased threat ratings, startle reflex, and skin conductance responses) compared to viewing safety cues. Interestingly, instructed threat effects occurred regardless of the person who cued shock threat (partner vs. unknown) and their facial expression (happy vs. angry). Taken together, these results demonstrate the flexible nature of facial information (i.e., facial expression and facial identity) to be easily learned as signals for threat or safety, even when showing loved ones.

A Nucleus Accumbens Tac1 Neural Circuit Regulates Avoidance Responses to Aversive Stimuli

Neural circuits that control aversion are essential for motivational regulation and survival in animals. The nucleus accumbens (NAc) plays an important role in predicting aversive events and translating motivations into actions. However, the NAc circuits that mediate aversive behaviors remain elusive. Here, we report that tachykinin precursor 1 (Tac1) neurons in the NAc medial shell regulate avoidance responses to aversive stimuli. We show that NAcTac1 neurons project to the lateral hypothalamic area (LH) and that the NAcTac1→LH pathway contributes to avoidance responses. Moreover, the medial prefrontal cortex (mPFC) sends excitatory inputs to the NAc, and this circuit is involved in the regulation of avoidance responses to aversive stimuli. Overall, our study reveals a discrete NAc Tac1 circuit that senses aversive stimuli and drives avoidance behaviors.

Effects of Imagery Rescripting on Emotional Responses During Imagination of a Socially Aversive Experience

Imagery rescripting (ImRs) of socially aversive memories is a promising intervention in the treatment of Social Anxiety Disorder. Little is known about the effects of ImRs on physiological responses to the rescripted socially aversive memory, which was the focus of this study in a healthy sample. Thirty individuals performed an imagination task measuring psychophysiological responses and subjective feelings (post-hoc) related to the rescripted memory, as well as to two control memories. In a within-subject design, participants completed the imagination task before and after a control intervention, and subsequently after one session ImRs of the socially aversive memory. At one-week follow-up, lasting effects on social anxiety and subjective feelings were assessed online (N = 26). ImRs of the socially aversive memory resulted in a significant reduction in negative feelings and activity of the corrugator supercilii, as well as a significant increase in valence and positive feelings related to the socially aversive memory compared to both control memories. However, only effects for positive feelings and corrugator supercilii were significantly stronger for ImRs compared to the control intervention. Lasting effects appeared for fear of negative evaluation and subjective emotional responses to the rescripted memory. These findings give preliminary evidence for the impact of ImRs on emotional aspects of the rescripted memory, indicating that ImRs might work through changing the representation of the aversive event in memory.

Supply Chain Performance with a Downside-Risk-Averse Retailer and Strategic Customers

Predicting future promotion information on markdowns, customers can maximize their utilities by deciding when to buy. With this strategic behavior, this paper investigates a downside-risk-averse retailer’s integrated stock and pricing problem using a single case study method. Analyzing effects of the downside risk aversion and strategic customers is our purpose. By exploring a two-phase newsvendor model with a retailer selling to strategic customers, our work determines the downside-risk-averse retailer’s equilibrium ordering level and selling price. On this basis, effects of the downside risk aversion and the strategic behavior on the retailer’s optimum decisions and profit are analyzed. We find that the reverse effect of the strategic behavior can be mitigated by the retailer’s downside risk constraint. We also extend the model to a decentralized supply chain case. It is found that a low (high) downside risk aversion would mean that the supply chain profit in the decentralized case can (cannot) dominate the centralized under some (any) wholesale price contracts when customers are strategic. In addition, for different risk aversions, we also construct contracts to optimize the supply chain profit. Our results will provide reference evidence of making operational management decisions for the downside-risk-averse retailer in the case of strategic customers.

Development of a nicotine aerosol self-administration model in rats and the effects of e-liquid flavors.

Electronic nicotine delivery system (ENDS) use is maintained by the positive reinforcement associated with preferred flavors. These flavors become conditioned reinforcers through pairings with primary reinforcers. This study sought to extend prior research with intravenous nicotine self-administration and develop a more ecologically valid preclinical model of aerosol self-administration in rats that incorporated flavors paired with sucrose. Rats were first trained to respond for oral sucrose with or without raspberry flavor to establish the flavor as a conditioned reinforcer for some groups. Rats were then exposed to aerosol self-administration. All groups responded for raspberry-flavored aerosol with or without nicotine. Rats responded more for raspberry flavored sucrose than unflavored sucrose. Despite raspberry increasing responding for sucrose, the flavor did not function as a conditioned reinforcer during aerosol self-administration and did not increase responding for nicotine. Throughout the aerosol self-administration phase, most groups responded more on the active than inactive lever, and some groups increased their response when the fixed ratio value was increased. At the end of the study, rats in nicotine groups earned similar or fewer aerosol deliveries than rats in vehicle groups. Aerosolized nicotine did not function as a reinforcer in this study, whereas aerosolized raspberry flavor may have maintained self-administration. Further preclinical investigation is needed to articulate the impact of flavors on ENDS use and whether they offset some aversive effects of nicotine or maintain responding on their own. If flavors reduce some aversive effects of self-administered nicotine, then policies to regulate flavors in e-liquids are prudent.

The effect of loss aversion and entitlement on cheating: An online experiment

We investigate how loss aversion and entitlement influence lying. We conduct an online experiment with a cheating task in which participants draw and report a number. Participants can cheat by reporting a different number to earn a higher payoff. We vary whether participants perform (or not) a real effort task to generate their endowment before the cheating task to evoke a sense of entitlement, and whether participants can cheat for an additional gain or to avoid a loss using a 2 (earned/not earned endowment) × 2 (loss/gain) design. We find no effect of loss aversion on cheating and only weak evidence of a prior stage of real effort on lying behavior. Furthermore, we find a correlation between real effort task performance and lying, but only in the gain domain. This is the first study to look at how entitlement affects cheating behavior in both the gain and loss domains.

Systematically investigating the role of context on effect replicability in reinstatement of fear in humans

Context is crucial in guiding behavior in an ever-changing world and contextual information plays a crucial role in associative learning processes. For instance, the return of fear (RoF) after successful extinction, which is used to study the mechanisms underlying relapse phenomena in fear- and stress-related disorders in an experimental model, is known to be context dependent as evident from phenomena such as renewal (contextual change) and reinstatement (re-exposure to an aversive event).Human adaptions of reinstatement paradigms have resulted in mixed findings: CS specific as well as unspecific RoF or unexpected “reinstated” conditioned responding in no reinstatement US control groups. Here, we systematically investigate the role of context (i.e., cue-context compound) on reinstatement-induced RoF in a human differential fear conditioning paradigm using subjective and psychophysiological measures in a large sample (N = 212) including reinstatement and control groups.Overall, response patterns in reinstatement-groups mirrored results from single-cue rodent work. Yet, only generalized, not differential RoF was observed. Remarkably, depending on outcome measure RoF was also observed under identical experimental context conditions without US-re-exposure, underlining effects of contextual change beyond the reinstatement-US and challenging reinstatement research in human subjects and highlight that future reinstatement work should focus on the operationalization of context.

Love More and Buy More? Behavioral Economics Analysis of Travel Preference and Travel Consumption

This study examined the interaction between travel preference and travel consumption from the perspectives of traditional and behavioral economics and analyzed the impact of travel preference on travel consumption using survey data. The WLS regression model was adopted to examine the influence of travel preference on travel consumption and the mediating role of travel demand in the relationship between travel Preference and travel consumption. The results showed that: (1) for domestic travel, the travel preference has a positive impact on travel consumption through the mediating role of travel demand; and (2) for outbound travel, the travel preference has a positive impact on outbound travel consumption through the mediating role of outbound travel demand under the transaction utility and loss aversion effects. Thus, our findings confirm previous evidence on the relevance of tourists’ preferences as a good predictor of travel consumption in the case of Chinese travelers.

A processing fluency perspective on overhead aversion: How much is too much?

AbstractOverhead aversion has afflicted the nonprofit sector in recent decades. Yet, questions remain regarding how high is too high from a donor perspective and at what level overhead expenses just “feel right.” Using processing fluency as a theoretical foundation, the central purpose of this research was to investigate whether a nonprofit overhead ratio fluency level exists that significantly reduces both donation likelihood and nonprofit perceptions. Results from two studies show that a 25% overhead ratio appears to be the proximate ceiling regarding what fluently fits within a potential donor's schema for acceptance. Overhead ratios exceeding this threshold tended to decrease donation likelihood and nonprofit perceptions in a relatively stable manner. Moreover, the 25% threshold seems most relevant to human and animal causes and not as relevant to arts and cultural nonprofits such as museums. The results suggest that donors have a preconceived overhead ratio limit. Nonprofits that exceed that threshold are in danger of deterring donors. If nonprofit overhead ratios exceed the donor fluency threshold, nonprofit managers should consider distinct promotional strategies that entice donors and diminish overhead aversion effects.

Memory representation of aversive social experiences in Social Anxiety Disorder

Aversive social experiences are proposed to be a risk factor for developing Social Anxiety Disorder (SAD). Many patients with SAD report associated daily life symptoms, such as intrusive re-experiencing (e.g., negatively distorted images of oneself), avoidance, alterations in cognitions and mood, as well as hyperarousal, resembling symptom dimensions of Posttraumatic Stress Disorder (PTSD). These PTSD-like symptoms may result from maladaptive processing and representation of the aversive social experiences in memory. Emotional hyperreactivity during memory retrieval of aversive social experiences is another feature of SAD which was found in previous studies. This study aimed to further investigate PTSD-like symptoms and emotional reactivity associated with etiologically relevant aversive social experiences and shed more light on a potential relationship between both. Eighty-five patients with SAD and 85 healthy controls (HC) participated in this cross-sectional study. It comprised an imagination task with self-report and physiological measures to assess emotional reactivity during the cued recall of the aversive social experience and clinical interviews to assess PTSD-like symptoms. We expected increased emotional reactivity and more severe PTSD-like symptoms in response to the aversive social experience in patients with SAD compared to HC, as well as a positive correlation between emotional reactivity and PTSD-like symptoms in patients with SAD. Indeed, patients with SAD showed emotional hyperreactivity (self-report, physiology) during the cued recall of the aversive social experiences, also when compared to two control memory conditions (neutral, negative non-social) and HC. Patients with SAD furthermore reported more severe PTSD-like symptoms compared to HC and intrusive re-experiencing symptoms were positively correlated with distress during imagery of the social aversive event in patients with SAD. These results might point toward a maladaptive representation of aversive social experiences in memory. Similar to PTSD, this maladaptive memory representation might promote the development of PTSD-like symptoms such as intrusive re-experiencing (e.g., in the form of intrusive self-images in patients with SAD), which might finally lead to and maintain symptoms of SAD.

Predictive impact of different acute cannabis intoxication effects with regard to abstinence motivation and cessation of use

Cannabis use is a common risk factor for psychoses. But although prevalence of consumption as well as potency of cannabis increased, the incidence of schizophrenia remained stable. The discontinuation hypothesis suggests that a potential increase of psychoses incidence may be relativized by more frequent cessation of consumption due to higher rates of adverse psychosis-like intoxication effects (PLE), caused by stronger cannabis. A mixed methods online survey was administered to 441 current and past users to analyze the predictive impact of different acute intoxication effects regarding abstinence motivation/cessation of use. Our hypothesis was that PLE would be experienced as the most aversive intoxication effect and therefore have the highest predictive significance. Possible confounds were included (craving, patterns of consumption and sociodemographics). Further analyzes compared past versus current users regarding the quality of intoxication effects, suggesting that past users retrospectively experienced more unpleasant experiences than current users. Free-text data explored subjective reasons for abstinence. We found that paranoid/dysphoric intoxication effects were most predictive for abstinence motivation. Less predictive were psychosis-like intoxication effects such as hallucinations. Group comparisons revealed significant more unpleasurable and less positive intoxication effects in past users compared with current users. Current users with the intention to stop consumption showed significantly more paranoia/dysphoria intoxication compared to users with no intention to stop use. As a conclusion, different intoxication experiences have different effects on abstinence motivation and substance use behavior. They therefore provide a focus that should be increasingly integrated into treatment concepts.

Habituation of the stress response multiplex to repeated cold pressor exposure.

Humans show remarkable habituation to aversive events as reflected by changes of both subjective report and objective measures of stress. Although much experimental human research focuses on the effects of stress, relatively little is known about the cascade of physiological and neural responses that contribute to stress habituation. The cold pressor test (CPT) is a common method for inducing acute stress in human participants in the laboratory; however, there are gaps in our understanding of the global state changes resulting from this stress-induction technique and how these responses change over multiple exposures. Here, we measure the stress response to repeated CPT exposures using an extensive suite of physiologic measures and state-of-the-art analysis techniques. In two separate sessions on different days, participants underwent five 90 s CPT exposures of both feet and five warm water control exposures, while electrocardiography (ECG), impedance cardiography, continuous blood pressure, pupillometry, scalp electroencephalography (EEG), salivary cortisol and self-reported pain assessments were recorded. A diverse array of adaptive responses are reported that vary in their temporal dynamics within each exposure as well as habituation across repeated exposures. During cold-water exposure there was a cascade of changes across several cardiovascular measures (elevated heart rate (HR), cardiac output (CO) and Mean Arterial Pressure (MAP) and reduced left ventricular ejection time (LVET), stroke volume (SV) and high-frequency heart rate variability (HF)). Increased pupil dilation was observed, as was increased power in low-frequency bands (delta and theta) across frontal EEG electrode sites. Several cardiovascular measures also habituated over repeated cold-water exposures (HR, MAP, CO, SV, LVET) as did pupil dilation and alpha frequency activity across the scalp. Anticipation of cold water induced stress effects in the time-period immediately prior to exposure, indexed by increased pupil size and cortical disinhibition in the alpha and beta frequency bands across central scalp sites. These results provide comprehensive insight into the evolution of a diverse array of stress responses to an acute noxious stressor, and how these responses adaptively contribute to stress habituation.

Zebrafish aversion to infrasound in an open field test.

Aquatic species are capable of detecting infrasound (sub-20 Hz frequencies) which may be a source of anthropogenic pollution and have a detrimental impact on the environmental fitness of fish. Infrasound is generated by infrastructure, producing acoustic frequency peaks that are not discernible by humans. The presence of these frequencies may therefore impact the environmental wellbeing of aquatic laboratory animals, which are often housed in spaces adjacent to facilities producing infrasound. To investigate the potential impact of infrasound, we used wild-type zebrafish (Danio rerio) and exposed them to short periods of infrasound at either 5, 10, 15, or 20 Hz, or 0 Hz as a control group. A motion-tracking software system was used to monitor fish movement in an open field test and arena location, distance moved, and immobility were quantified. There was a significant effect of 15 Hz which caused the fish to spend more time away from the infrasound source. The 20 Hz group also spent significantly less time in the zone closest to the speaker. There were no differences in distance moved or immobility between infrasound and control groups. These findings demonstrate that 15 Hz infrasound has aversive effects on zebrafish, causing them to move away from the sound source. To enhance environmental enrichment and wellbeing of aquatic laboratory animals, sources of infrasound pollution should be investigated and mitigated.

Cryptocurrency and Innovation: The Relationship with Technology in Light of Risk Aversion and Market Sentiment

The paper performs a (Panel) Moderated Regression, Causality and Cointegration (complete version) test on the relationship between the exchange rate of major selected cryptocurrencies vs. major fiat currencies, and selected technology indices of various geographic areas and economic groups in the world, representative of different countries or areas in the world (Europe) and for different levels of market capitalization. The dataset allows to focus on the comparison pre- and post-Covid19 (complete version), testing the relationship in those two different time frames. The novelty of the study is the use of risk aversion and VIX volatility index (market sentiment) as control variables. Various indices of risk aversion have been developed, presenting different levels of trade-off in terms of availability (ease of calculation) and effectiveness. A good candidate seems to be the Global Risk Appetite Index (GRAI) by Kumar and Persaud (2002). As for the VIX index, it has been widely used as a proxy of market sentiment, but rarely applied to the understanding of currency trends (especially cryptocurrency). Our expectation is to observe some significant moderation effect for some of the indicators considered, in general and when observing the data for different sub-periods. with investors probably trying to hedge equity investments and diversify their portfolios differently, with risk aversion and VIX index to be a driving factor of those choices. We also expect results to be confirmed by the Causality and Cointegration (complete version) test. The paper aims to contribute to the Fintech literature and shed light on the possibilities of diversification offered by tech-related portfolios. As a corollary, it aims to determine how the effect of risk aversion and general market risk sentiment drives those choices. Keywords: Cryptocurrency; Technology Index; Risk Appetite; Market Sentiment; Causality; Cointegration; Panel Regression.