The impact of stress on tournament entry

Mitofusin-2 in nucleus accumbens D2-MSNs regulates social dominance and neuronal function

The nucleus accumbens (NAc) is a brain hub regulating motivated behaviors, including social competitiveness. Mitochondrial function in the NAc links anxiety with social competitiveness, and the mitochondrial fusion protein mitofusin 2 (Mfn2) in NAc neurons regulates anxiety-related behaviors. However, it remains unexplored whether accumbal Mfn2 levels also affect social behavior and whether Mfn2 actions in the emotional and social domain are driven by distinct cell types. Here, we found that subordinate-prone highly anxious rats show decreased accumbal Mfn2 levels and that Mfn2 overexpression promotes dominant behavior. In mice, selective Mfn2 downregulation in NAc dopamine D2 receptor-expressing medium spiny neurons (D2-MSNs) induced social subordination, accompanied by decreased accumbal mitochondrial functions and decreased excitability in D2-MSNs. Instead, D1-MSN-targeted Mfn2 downregulation affected competitive ability only transiently and likely because of an increase in anxiety-like behaviors. Our results assign dissociable cell-type specific roles to Mfn2 in the NAc in modulating social dominance and anxiety.

Does Local Government Competition Reduce Environmental Governance Performance? The Role of Public Value Conflict and Media Sentiment

With the increasing attention paid to environmental protection and sustainable development in various countries worldwide, the relationship between local government competition and environmental governance has become more subtle and complex. This paper provides new insight into their relationship based on public value theory and media sentiment perspective. Utilizing panel data from 2012 to 2019 in 216 cities in China, this study integrated Data Envelopment Analysis, Conflicting Attitudes Model, Computer-Aided Text Analysis, and machine learning-based sentiment analysis, as well as nonlinear mediation model to empirically test the relationships among local governments’ competition pressure, public value conflict, media sentiments, and environmental governance performance. The study found that: (1) Competition pressure and environmental governance performance exist in a “U-curved” relationship. (2) The core mechanism of the above relationship lies in the mediating role of public value conflict. Within a specific range, the public value conflict faced by local governments increases as competition pressure increases. This conflict would push local governments into a dilemma and induce them to commit misconduct. However, when competition pressure exceeds this range, the public value conflict faced by local governments will be weakened, leading environmental governance performance to rebound. (3) Negative media sentiments significantly alleviate the negative impact of public value conflict on environmental governance performance. This study helps researchers and policymakers recognize government competition’s influence on environmental governance from a public value perspective, with further exploration and confirmation of the moderating role of media sentiments. It also provides theoretical and policy enlightenment for rethinking the behavior logic of local government and solving the dilemma of local government environmental governance.

Contactless Real-Time Heart Rate Predicts the Performance of Elite Athletes: Evidence From Tokyo 2020 Olympic Archery Competition

It is widely recognized that psychological stress impairs performance for elite athletes, yet direct evidence is scarce when it comes to high-stakes competition because measuring real-time psychological stress without interference is often challenging. Contactless real-time heart rate-a technology-enabled biomarker of stress-was measured and broadcast on TV during the 2020 Tokyo Olympics archery competition for the first time in sports. Here we examined whether the real-time heart rate of 122 adult archers predicted their performance in this unique setting. We found that higher heart rate-which indicates an increase in psychological stress-is associated with lower scores, correlation coefficient r(2096) = -.076, p < .001, and the observation is robust after we controlled for fixed effects at the individual and match level. Our results provide the first direct evidence in support of the detrimental effect of psychological stress measured by a real-time biomarker in a high-stakes competitive setting.

Effects of acute psychosocial stress on interpersonal cooperation and competition in young women

Although tend-and-befriend is believed to be the dominant stress response in women, little is known regarding the effects of acute psychosocial stress on different dynamic social interactions. To measure these effects, 80 female participants were recruited, paired into the dyads, and instructed to complete cooperative and competitive key-pressing tasks after experiencing acute stress or a control condition. Each dyad of participants should press the key synchronously when the signal was presented in the cooperative task and as fast as possible in the competitive task. During the tasks, brain activities of prefrontal and right temporo-parietal areas were recorded from each dyad using functional near-infrared spectroscopy (fNIRS). The results showed that acute psychosocial stress evidently promoted competitive behavior, accompanied by increased interpersonal neural synchronization (INS) in the right dorsolateral prefrontal cortex. Despite the lack of a significant difference in the overall cooperation rate, the response time difference between two stressed participants markedly declined over time with more widespread INS in the prefrontal cortex, suggesting that there ensued cooperative improvement among stressed women. These findings behaviorally and neurologically revealed context-dependent response patterns to psychosocial stress in women during dynamic social interactions.

Acute stress does not affect economic behavior in the experimental laboratory

We report statistical results from a laboratory experiment in which participants were required to make decisions with monetary consequences in several solitary and interactive situations under acute stress. Our study follows the tradition of behavioral and experimental economics in selecting the experimental situations and incorporates elements from medical and psychological research in the way stress is induced and measured. It relies on a larger sample, with 192 volunteers, than previous studies to achieve higher statistical power. The main conclusion, drawn from binary comparisons between the treatment and reference groups, is that acute stress does not have a significant impact on cognitive skills, strategic sophistication, risk attitudes, altruism, cooperativeness, or nastiness. Regression analysis, controlling for psycho-social characteristics, corroborates these findings, while also suggesting that acute stress significantly decreases men’s risk aversion (as measured by a lottery-choice risk-elicitation task).

Competitiveness and individual characteristics: a double-blind placebo-controlled study using oxytocin

Oxytocin-enhanced prosocial behaviour depends on individual characteristics. This study investigated the relationship between oxytocin and competitiveness, which is another important social trait and predicts economic and social outcomes. In this double-blind, randomized, and placebo-controlled study of 192 male participants, we examined whether oxytocin moderates competitiveness and whether the effect of oxytocin on competitiveness is amplified in individuals with autistic traits. While our results show no relationship between oxytocin and competitiveness, we observed suggestive patterns: albeit not significantly, oxytocin reduced and enhanced competitiveness among participants without autistic traits and among their counterparts with autistic traits, respectively.

Activación emocional en sujetos humanos: procedimientos para la inducción experimental de estrés

Resumen El estudio de los efectos del estrés sobre la cognición y el comportamiento es un área de especial interés y desarrollo científico, tanto para la Psicología como para las Neurociencias. La inducción de estrés constituye un elemento fundamental en estos estudios, pues permite la manipulación de esta forma de activación emocional, como variable independiente, para observar su efecto sobre la conducta; no obstante, esta inducción debe ser suficiente para generar incrementos significativos en los niveles de cortisol y cumplir los estándares éticos establecidos para la experimentación con humanos. El presente artículo tiene como propósito aportar una revisión general sobre la activación emocional, para profundizar en el conocimiento acerca de los procedimientos utilizados en la inducción experimental de estrés en sujetos humanos. Se concluye que se requiere el diseño de protocolos más eficaces, para lo cual, el uso de las simulaciones y otras herramientas tecnológicas puede ser de gran utilidad.

Social learning under acute stress

Individual decisions are often made simultaneously under social influence and acute stress, yet despite its importance, it has been largely unknown how stress influences the weight which people place on others' decisions. To answer this I ran a laboratory experiment where 140 subjects were exposed to an acute stressor or a control procedure, immediately before and after which we tested their behavior in a simple Bayesian-updating task. Using three measures (cortisol, heart-rate and mood questionnaire) I show that subjects in the treatment group were under considerable levels of stress. Although stress was expected to increase the weight they put on information coming from the observation of others, I see no effect of stress on subjects' behavior, either after private or public signals, or on the precision of the updating behavior. This holds across different specifications and after the addition of various personal controls, including the Big-Five personality traits and the psychological measure of conformity.

Cortisol boosts risky decision-making behavior in men but not in women

Acute stress may escalate risky decision-making in men, while there is no such effect in women. Although first evidence links these gender-specific effects of stress to stress-induced changes in cortisol, whether elevated cortisol is indeed sufficient to boost risk-taking, whether a potential cortisol effect depends on simultaneous noradrenergic activation, and whether cortisol and noradrenergic activation exert distinct effects on risk-taking in men and women is unknown. In this experiment, we therefore set out to elucidate the impact of cortisol and noradrenergic stimulation on risky decision-making in men and women. In a fully-crossed, placebo-controlled, double-blind design, male and female participants received orally either a placebo, hydrocortisone, yohimbine, an alpha-2-adrenoceptor-antagonist leading to increased noradrenergic stimulation, or both drugs before completing the balloon analogue risk task, a validated measure of risk-taking. Overall, participants' choice was risk-sensitive as reflected in reduced responding in high- compared to moderate- and low-risk conditions. Cortisol, however, led to a striking increase in risk-taking in men, whereas it had no effect on risk-taking behavior in women. Yohimbine had no such effect and the gender-specific effect of cortisol was not modulated by yohimbine. Our data show that cortisol boosts risk-taking behavior in men but not in women. This differential effect of cortisol on risk-taking may drive gender differences in risky decision-making under stress.