Neuroeconomics of suicide.

Suicidal behavior is a leading cause of injury and death worldwide. Suicide has been associated with psychiatric illnesses such as depression and schizophrenia, as well as economic uncertainty, and social/cultural factors. This study proposes a neuroeconomic framework of suicide. Neuroeconomic parameters (e.g., risk-attitude, probability weighting, time discounting in intertemporal choice, and loss aversion) are predicted to be related to suicidal behavior. Neurobiological and neuroendocrinological substrates such as serotonin, dopamine, cortisol (HPA axis), nitric oxide, serum cholesterol, epinephrine, norepinephrine, gonadal hormones (e.g., estradiol and progesterone), dehydroepiandrosterone (DHEA) in brain regions such as the orbitofrontal/dorsolateral prefrontal cortex and limbic regions (e.g., the amygdala) may supposedly be related to the neuroeconomic parameters modulating the risk of suicide. The present framework puts foundations for ―molecular neuroeconomics‖ of decision-making processes underlying suicidal behavior

Neuroeconomics of health care financing options: willingness to pay and save

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Comparison of probabilistic choice models in humans

BACKGROUND: Probabilistic choice has been attracting attention in psychopharmacology and neuroeconomics. Several parametric models have been proposed for probabilistic choice; entropy model, Prelec's probability weight function, and hyperbola-like probability discounting functions. METHODS: In order to examine (i) fitness of the probabilistic models to behavioral data, (ii) relationships between the parameters and psychological processes, e.g., aversion to possible non-gain in each probabilistic choice and aversion to unpredictability, we estimated the parameters and AICc (Akaike Information Criterion with small sample correction) of the probabilistic choice models by assessing the points of subjective equality at seven probability values (95%–5%). We examined both fitness of the models parametrized by utilizing AICc, and the relationships between the model parameters and equation-free parameter of aversion to possible non-gain. RESULTS: Our results have shown that (i) the goodness of fitness for group data was [Entropy model>Prelec's function>General hyperbola>Simple hyperbola]; while Prelec's function best fitted individual data, (ii) aversion to possible non-gain and aversion to unpredictability are distinct psychological processes. CONCLUSION: Entropy and Prelec models can be utilized in psychopharmacological and neuroeconomic studies of risky decision-making

Deep Brain Stimulation of Nucleus Accumbens Region in Alcoholism Affects Reward Processing

The influence of bilateral deep brain stimulation (DBS) of the nucleus nucleus (NAcc) on the processing of reward in a gambling paradigm was investigated using H2[15O]-PET (positron emission tomography) in a 38-year-old man treated for severe alcohol addiction. Behavioral data analysis revealed a less risky, more careful choice behavior under active DBS compared to DBS switched off. PET showed win- and loss-related activations in the paracingulate cortex, temporal poles, precuneus and hippocampus under active DBS, brain areas that have been implicated in action monitoring and behavioral control. Except for the temporal pole these activations were not seen when DBS was deactivated. These findings suggest that DBS of the NAcc may act partially by improving behavioral control

Neuronal Distortions of Reward Probability without Choice

Reward probability crucially determines the value of outcomes. A basic phenomenon, defying explanation by traditional decision theories, is that people often overweigh small and underweigh large probabilities in choices under uncertainty. However, the neuronal basis of such reward probability distortions and their position in the decision process are largely unknown. We assessed individual probability distortions with behavioral pleasantness ratings and brain imaging in the absence of choice. Dorsolateral frontal cortex regions showed experience dependent overweighting of small, and underweighting of large, probabilities whereas ventral frontal regions showed the opposite pattern. These results demonstrate distorted neuronal coding of reward probabilities in the absence of choice, stress the importance of experience with probabilistic outcomes and contrast with linear probability coding in the striatum. Input of the distorted probability estimations to decision-making mechanisms are likely to contribute to well known inconsistencies in preferences formalized in theories of behavioral economics

Strategie di adattamento al cambiamento climatico per il settore vitivinicolo: un’applicazione della Teoria del Prospetto Cumulativo

The work analyses adaptation strategies to cope with extreme events and climate change in viticultural sector. Tools for complex systems analysis are integrated with probabilistic methods and operational research to account for uncertainty and the subjective perception of farmers. The concepts of Expected Utility and Cumulative Prospect Theory are considered to compare expected and prospected damages. The study area is located in the Chianti Classico district (Tuscany). A combination of fans, anti-hail nets and emergency irrigation is suggested as strategies in current scenario. The future climate projections suggest the need of fixed irrigation systems and the modification of production disciplinary. Multi-risk insurance does not seem to be an attractive strategy due to area peculiarities

Striatal topography of probability and magnitude information for decisions under uncertainty

Most decisions involve some element of uncertainty. When the outcomes of these decisions have different likelihoods of occurrence, the decision-maker must consider both the magnitude of each outcome and the probability of its occurrence, but how do individual decision makers combine the two dimensions of magnitude and probability? Here, we approach the problem by separating in time the presentation of magnitude and probability information, and focus the analysis of fMRI activations on the first piece of information only. Thus, we are able to identify distinct neural circuits for the two dimensions without the confounding effect of divided attention or the cognitive operation of combining them. We find that magnitude information correlates with the size of the response of the ventral striatum while probability information correlates with the response in the dorsal striatum. The relative responsiveness of these two striatal regions correlates with the behavioral tendency to weight one more than the other. The results are consistent with a second-order process of information aggregation in which individuals make separate judgments for magnitude and probability and then integrate those judgments

Expert Financial Advice Neurobiologically “Offloads” Financial Decision-Making under Risk

BACKGROUND: Financial advice from experts is commonly sought during times of uncertainty. While the field of neuroeconomics has made considerable progress in understanding the neurobiological basis of risky decision-making, the neural mechanisms through which external information, such as advice, is integrated during decision-making are poorly understood. In the current experiment, we investigated the neurobiological basis of the influence of expert advice on financial decisions under risk. METHODOLOGY/PRINCIPAL FINDINGS: While undergoing fMRI scanning, participants made a series of financial choices between a certain payment and a lottery. Choices were made in two conditions: 1) advice from a financial expert about which choice to make was displayed (MES condition); and 2) no advice was displayed (NOM condition). Behavioral results showed a significant effect of expert advice. Specifically, probability weighting functions changed in the direction of the expert's advice. This was paralleled by neural activation patterns. Brain activations showing significant correlations with valuation (parametric modulation by value of lottery/sure win) were obtained in the absence of the expert's advice (NOM) in intraparietal sulcus, posterior cingulate cortex, cuneus, precuneus, inferior frontal gyrus and middle temporal gyrus. Notably, no significant correlations with value were obtained in the presence of advice (MES). These findings were corroborated by region of interest analyses. Neural equivalents of probability weighting functions showed significant flattening in the MES compared to the NOM condition in regions associated with probability weighting, including anterior cingulate cortex, dorsolateral PFC, thalamus, medial occipital gyrus and anterior insula. Finally, during the MES condition, significant activations in temporoparietal junction and medial PFC were obtained. CONCLUSIONS/SIGNIFICANCE: These results support the hypothesis that one effect of expert advice is to "offload" the calculation of value of decision options from the individual's brain