Stress and Decision Making: Effects on Valuation, Learning, and Risk-taking

A wide range of stressful experiences can influence human decision making in complex ways beyond the simple predictions of a fight-or-flight model. Recent advances may provide insight into this complicated interaction, potentially in directions that could result in translational applications. Early research suggests that stress exposure influences basic neural circuits involved in reward processing and learning, while also biasing decisions toward habit and modulating our propensity to engage in risk-taking. That said, a substantial array of theoretical and methodological considerations in research on the topic challenge strong cross study comparisons necessary for the field to move forward. In this review we examine the multifaceted stress construct in the context of human decision making, emphasizing stress’ effect on valuation, learning, and risk-taking

The Effects of Acute Stress Exposure on Neural Correlates of Pavlovian Conditioning with Monetary Gains and Losses

Pavlovian conditioning involves the association of an inherently neutral stimulus with an appetitive or aversive outcome, such that the neutral stimulus itself acquires reinforcing properties. Across species, this type of learning has been shown to involve subcortical brain regions such as the striatum and the amygdala. It is less clear, however, how the neural circuitry involved in the acquisition of Pavlovian contingencies in humans, particularly in the striatum, is affected by acute stress. In the current study, we investigate the effect of acute stress exposure on Pavlovian conditioning using monetary reinforcers. Participants underwent a partial reinforcement conditioning procedure in which neutral stimuli were paired with high and low magnitude monetary gains and losses. A between-subjects design was used, such that half of the participants were exposed to cold stress while the remaining participants were exposed to a no stress control procedure. Cortisol measurements and subjective ratings were used as measures of stress. We observed an interaction between stress, valence, and magnitude in the ventral striatum, with the peak in the putamen. More specifically, the stress group exhibited an increased sensitivity to magnitude in the gain domain. This effect was driven by those participants who experienced a larger increase in circulating cortisol levels in response to the stress manipulation. Taken together, these results suggest that acute stress can lead to individual differences in circulating cortisol levels which influence the striatum during Pavlovian conditioning with monetary reinforcers

Shake me the money!

During a natural disaster, the negative supply shock due to the destruction of productive capacity is counteracted by a positive demand shock due to public grants for assistance and reconstruction positing an identification issue in empirical work. Focusing on the 2009 'Aquilano' earthquake in Italy as a case study, we take advantage of quantified measure of damages for 75,424 buildings to estimate the negative supply shock and of a law issued to allocate reconstruction grants, which resulted in a sharp, exogenous discontinuity in transfers and output behavior across neighboring municipalities to estimate the positive demand shock. Diff-in-diff analysis suggests that local output multipliers of reconstruction grants (net of marginal tax rebates) are below unity. Yet the size of the grants act as a public insurance scheme, preventing a fall in output

The Impact of Earthquakes on Economic Activity: Evidence from Italy

Although earthquakes are large idiosyncratic shocks for affected regions, little is known of their impact on economic activity. Seismic events are rare, the data is crude (the Richter scale measures the magnitude but says nothing of the associated damages) and counterfactuals are often entirely absent. We suggest an innovative identification strategy to address these issues based on the so-called ’Mercalli scale’ ranks - a geophysical methodology devised to gauge seismic damages relying on a newly compiled dataset following 95 Italian provinces from 1986 to 2011 (including 22 seismic episodes) offering an ideal ground for identification. Also, we carry out counterfactuals taking advantage of ex ante identical neighboring provinces that only differ ex post in terms of damages. Contrary to conventional views, we find that the impact of seismic events on output is negligible (or even positive) including after the most devastating events

Reconstruction multipliers

A law issued to allocate reconstruction grants following the 2009 "Aquilano" earthquake has resulted in a large and unanticipated discontinuity across municipalities with comparable damages. Using diff-in-diff analysis we estimate the "local spending" and the "local tax" multipliers--according to the composition of the stimulus--controlling for the negative supply shock generated by the event. The stimulus prevented a fall in economic activity and the multiplicative effects of tax cuts are estimated much higher than those of spending. Our results underline the importance of countercyclical fiscal interventions and suggest the most effective composition of such a stimulus

Reconstruction multipliers

A law issued to allocate reconstruction grants following the 2009 "Aquilano" earthquake has resulted in a large and unanticipated discontinuity across municipalities with comparable damages. Using diff-in-diff analysis we estimate the "local spending" and the "local tax" multipliers--according to the composition of the stimulus--controlling for the negative supply shock generated by the event. The stimulus prevented a fall in economic activity and the multiplicative effects of tax cuts are estimated much higher than those of spending. Our results underline the importance of countercyclical fiscal interventions and suggest the most effective composition of such a stimulus

Acute Stress Modulates Risk Taking in Financial Decision Making

People’s decisions are often susceptible to various demands exerted by the environment, leading to stressful conditions. Although a goal for researchers is to elucidate stress-coping mechanisms to facilitate decisionmaking processes, it is important to first understand the interaction between the state created by a stressful environment and how decisions are performed in such environments. The objective of this experiment was to probe the impact of exposure to acute stress on financial decision making and examine the particular influence of stress on decisions with a positive or negative valence. Participants’ choices exhibited a stronger reflection effect when participants were under stress than when they were in the nostress control phase. This suggests that stress modulates risk taking, potentially exacerbating behavioral bias in subsequent decision making. Consistent with dual-process approaches, decision makers fall back on automatized reactions to risk under the influence of disruptive stress

Resonant Axisymmetric Modes

Axisymmetric modes in shaped tokamak plasmas are normally associated with vertical displacement events. However, not enough attention has been given to the fact that these modes can be resonant in two different ways. Firstly, for a plasma bounded by a divertor separatrix, a generic n=0 ideal-MHD perturbation, ξ, is singular at the divertor X- point(s), where Beq · ∇ξ = 0, with Beq the equilibrium magnetic field. As a consequence, n=0 perturbations can give rise to current sheets localized along the divertor separatrix. Secondly, a feedback-stabilized n=0 mode tends to acquire an Alfv ́enic oscillation frequency. As a result, a resonant interaction with energetic particle orbits can lead to a new type of fast ion instability

Experimental sexual selection reveals rapid evolutionary divergence in sex-specific transcriptomes and their interactions following mating

Work was supported by the Natural Environment Research Council (NE/I014632/1 to M.G.R., A.R.C., and R.R.S), the Natural Environment Research Council Biomolecular Analysis Facility (NBAF654 to M.G.R), and the Swedish Research Council (Vetenskapsrådet; 2018-04598 to R.R.S).Postcopulatory interactions between the sexes in internally fertilizing species elicits both sexual conflict and sexual selection. Macroevolutionary and comparative studies have linked these processes to rapid transcriptomic evolution in sex-specific tissues and substantial transcriptomic postmating responses in females, patterns of which are altered when mating between reproductively isolated species. Here we test multiple predictions arising from sexual selection and conflict theory about the evolution of sex-specific and tissue-specific gene expression and the postmating response at the microevolutionary level. Following over 150 generations of experimental evolution under either reduced (enforced monogamy) or elevated (polyandry) sexual selection in Drosophila pseudoobscura, we found a substantial effect of sexual selection treatment on transcriptomic divergence in virgin male and female reproductive tissues (testes, male accessory glands, the female reproductive tract and ovaries). Sexual selection treatment also had a dominant effect on the postmating response, particularly in the female reproductive tract ? the main arena for sexual conflict - compared to ovaries. This effect was asymmetric with monandry females typically showing more postmating responses than polyandry females, with enriched gene functions varying across treatments. The evolutionary history of the male partner had a larger effect on the postmating response of monandry females, but females from both sexual selection treatments showed unique patterns of gene expression and gene function when mating with males from the alternate treatment. Our microevolutionary results mostly confirm comparative macroevolutionary predictions on the role of sexual selection on transcriptomic divergence and altered gene regulation arising from divergent coevolutionary trajectories between sexual selection treatments.Publisher PDFPeer reviewe