The neural basis of loss aversion in decision-making under risk

People typically exhibit greater sensitivity to losses than to equivalent gains when making decisions. We investigated neural correlates of loss aversion while individuals decided whether to accept or reject gambles that offered a 50/50 chance of gaining or losing money. A broad set of areas (including midbrain dopaminergic regions and their targets) showed increasing activity as potential gains increased. Potential losses were represented by decreasing activity in several of these same gain-sensitive areas. Finally, individual differences in behavioral loss aversion were predicted by a measure of neural loss aversion in several regions, including the ventral striatum and prefrontal cortex.     

The connectome of a decision-making neural network

In order to understand the nervous system, it is necessary to know the synaptic connections between the neurons, yet to date, only the wiring diagram of the adult hermaphrodite of the nematode Caenorhabditis elegans has been determined. Here, we present the wiring diagram of the posterior nervous system of the C. elegans adult male, reconstructed from serial electron micrograph sections. This region of the male nervous system contains the sexually dimorphic circuits for mating. The synaptic connections, both chemical and gap junctional, form a neural network with four striking features: multiple, parallel, short synaptic pathways directly connecting sensory neurons to end organs; recurrent and reciprocal connectivity among sensory neurons; modular substructure; and interneurons acting in feedforward loops. These features help to explain how the network robustly and rapidly selects and executes the steps of a behavioral program on the basis of the inputs from multiple sensory neurons.     

The neural basis of altruistic punishment

Many people voluntarily incur costs to punish violations of social norms. Evolutionary models and empirical evidence indicate that such altruistic punishment has been a decisive force in the evolution of human cooperation. We used H2 15O positron emission tomography to examine the neural basis for altruistic punishment of defectors in an economic exchange. Subjects could punish defection either symbolically or effectively. Symbolic punishment did not reduce the defector's economic payoff, whereas effective punishment did reduce the payoff. We scanned the subjects' brains while they learned about the defector's abuse of trust and determined the punishment. Effective punishment, as compared with symbolic punishment, activated the dorsal striatum, which has been implicated in the processing of rewards that accrue as a result of goal-directed actions. Moreover, subjects with stronger activations in the dorsal striatum were willing to incur greater costs in order to punish. Our findings support the hypothesis that people derive satisfaction from punishing norm violations and that the activation in the dorsal striatum reflects the anticipated satisfaction from punishing defectors.     

The neural basis for learning of simple motor skills

The vestibulo-ocular reflex (VOR) is a simple movement that has been used to investigate the neural basis for motor learning in monkeys. The function of the VOR is to stabilize retinal images by generating smooth eye movements that are equal and opposite to each head movement. Learning occurs whenever image motion occurs persistently during head turns; as a result image stability is gradually restored. A hypothesis is proposed in which the output from the cerebellar cortex of the flocculus guides learning; the locus of learning is in the brain stem, in VOR pathways that are under inhibitory control from the flocculus. Other, parallel VOR pathways do not receive inputs from the flocculus and are not subject to learning. Similarities among the VOR and other motor systems suggest some organizing principles that may apply in many forms of motor learning.     

The neural basis of intuitive best next-move generation in board game experts

The superior capability of cognitive experts largely depends on quick automatic processes. To reveal their neural bases, we used functional magnetic resonance imaging to study brain activity of professional and amateur players in a board game named shogi. We found two activations specific to professionals: one in the precuneus of the parietal lobe during perception of board patterns, and the other in the caudate nucleus of the basal ganglia during quick generation of the best next move. Activities at these two sites covaried in relevant tasks. These results suggest that the precuneus-caudate circuit implements the automatic, yet complicated, processes of board-pattern perception and next-move generation in board game experts.     

Understanding overbidding: using the neural circuitry of reward to design economic auctions

We take advantage of our knowledge of the neural circuitry of reward to investigate a puzzling economic phenomenon: Why do people overbid in auctions? Using functional magnetic resonance imaging (fMRI), we observed that the social competition inherent in an auction results in a more pronounced blood oxygen level-dependent (BOLD) response to loss in the striatum, with greater overbidding correlated with the magnitude of this response. Leveraging these neuroimaging results, we design a behavioral experiment that demonstrates that framing an experimental auction to emphasize loss increases overbidding. These results highlight a role for the contemplation of loss in understanding the tendency to bid "too high." Current economic theories suggest overbidding may result from either "joy of winning" or risk aversion. By combining neuroeconomic and behavioral economic techniques, we find that another factor, namely loss contemplation in a social context, may mediate overbidding in auctions.     

典范性状对的决策分析

【目的】对典范性状对进行决策分析,为多数量性状的选择提供一种简便的方法。【方法】运用通径分析的决策分析方法对典范组合性状对进行决策分析。【结果】建立了典范性状对的通径分析模型;分析得到典范性状对可以用以供选择的各性状xi(i=1,2,…,m)为因,典范目标性状Hig为果的中心线性回归模型表述;定义了各选择性状对典范目标性状的决策系数,各决策系数代表了各选择性状对典范目标性状的综合效用。【结论】通过各性状决策系数的确定,选择组合性状中的主载性状、限制性状和辅助性状,育种者就可根据个体的性状表现来选择,以达到对典范目标性状所期望的遗传进展。     

The economic status of the elderly

Augmented by public programs such as Social Security and Medicare, incomes of the elderly in the United States have grown more rapidly during the last several decades than have the incomes of other groups, so that on average the elderly are at least as well off as the nonelderly. Not all elderly, however, have done as well: widows, in particular, have high poverty rates. The economic prospects of the elderly during the next few decades are good because of the large work force from the baby-boom cohort. In the distant future a large fraction of the population will be elderly, which will probably lead to a deterioration in their economic status. Today, the main problems center on the distribution of economic resources among the elderly and on uncertainties such as costs of medical care.     

技术引进中企业利益相关方的博弈分析

技术引进是企业快速提升技术创新能力,实现跨越式发展的捷径.在我国企业技术引进中,地方政府主导企业技术引进活动,引进企业与技术输出方目标完全不一致,地方政府与中央政府总体利益存在冲突.各利益相关主体相互多重博弈的结果使地方政府处于博弈的核心地位,因此,为企业能够合理引进技术,应构建新型的地方政府与企业的关系,努力限制技术输出方的非合作博弈行为,通过制度创新改变中央与地方政府的博弈结构.     

The economic impact of AIDS in the United States

This analysis of several previous studies of the cost of AIDS suggests that the lifetime cost of medical care per patient will not exceed +80,000, an amount similar to the cost of treating other serious illnesses. If current projections of future AIDS cases are accurate, the cumulative lifetime costs of 270,000 cases diagnosed between 1981 and the end of 1991 will not exceed +22 billion. This amount is small compared with total U.S. medical spending. The economic impact of AIDS on San Francisco, New York, and some other cities, however, is likely to be more serious. The AIDS epidemic will also highlight the financial problems of Americans who face large medical bills without adequate insurance.     

利用转置矩阵进行工程方案决策研究

根据工程企业在经营决策方面存在的多方案多级决策问题,提出转置矩阵法多目标多级决策的计 算模型,并应用该模型对工程实例进行了决策,此模型适宜于用计算机进行多方案多级决策。     

江苏省金融支持和农业经济增长的实证分析——基于13市面板数据的经验分析

以江苏省为例对金融支持和农业经济增长进行实证研究.考察江苏省13个城市在1996至2005年农业产量与相关金融支持要素之间的关系,包括江苏省3大区域各自财政农业支出和金融机构农业信贷等投入;利用Cobb-Douglas生产函数构建农业生产的固定影响变截距panel data模型.结果显示苏南地区农业总产值总体变化不大,其中苏南每年金融支持量的增长速度缓慢则是重要原因之一,而苏中、苏北地区都出现r明显的上升趋势,主要因为金融支持量的增长速度相对比较显著.最后提出了相应的政策建议.     

经济审判庭的撤销与经济法诉讼机制的构建

存在近20年的经济审判庭因最高人民法院的机构改革而被裁撤了,由此引发了对经济法诉讼机制构建问题的思考。本文从剖析经济法诉讼的特点入手,运用比较法研究、借鉴西方的先进经验,并在此基础上探讨中国经济法诉讼机制的构建问题。     

我国公共决策咨询现状及发展战略研究

公共决策咨询是一种非常重要的咨询形式,是我国决策科学化的重要手段和保证。本文在分析我国公共决策咨询的特点、功能以及所发挥的作用的基础上,了解我国公共决策咨询机构的现状,认真总结我国公共决策咨询所存在的问题,提出了一些能促进我国公共决策咨询系统的建设和完善的措施,使公共决策咨询能更好地为科学决策做出贡献。     

The ecological basis of the indigenous Nahua agriculture in the sixteenth century

The study of agriculture in ancient societies is of vital importance for the understanding of their ecological basis. This article discusses data gathered from Alonso de Molina's dictionary, published in Mexico City in 1571. Molina's information on soil, rain, plants, technology, and human labor applied to agricultural activities gives a picture of the complexity of the several native agricultural systems practiced at that time. Since the Sixteenth Century, native agriculture was impacted by the introduction of new plants, animals, agricultural equipment, and techniques from the Old World. A combination of the two agricultural models conform a new Mexican model of agriculture along the Colonial times. The knowledge of Sixteenth Century agricultural systems is fundamental for the understanding of the history and the conformation of contemporary agro-ecosystems. Recent studies on ecology and social anthropology agree on the necessity to take into account historical data for the discussion of ecological sustainability.     

冷风机的经济优化

本文介绍了结霜工况下冷风机的经济优化设计方法。在设计过程中,考虑了翅片表现结霜随着时间增长及其对传热和空气流动阻力的影响,肋片节距、除霜间隔时间对冷风机换热性能和年总费用的影响,为优化设计过程中蒸发温度、蒸发器的列数的选取提供了理论依据。在以上分析的基础上,建立了相应的数学模型,并用Ｃ语言编制了优化设计程序进行模拟计算。     

The economic consequences of immigration

Available research supports several major conclusions about the economic consequences of immigration. (i) The aggregate impacts of foreign workers on the earnings and employment of native workers are quite small, but differ for selected population subgroups and high ethnic density labor markets. (ii) Immigrants who arrived during the 1970s are less skilled than earlier arrivals, and their earnings will remain substantially below those of natives throughout their working lives. (iii) The evidence on immigrants' receipt of public assistance income is inconclusive.     

The energetic basis of specificity in the Eco RI endonuclease--DNA interaction

High sequence selectivity in DNA-protein interactions was analyzed by measuring discrimination by Eco RI endonuclease between the recognition site GAATTC and systematically altered DNA sites. Base analogue substitutions that preserve the sequence-dependent conformational motif of the GAATTC site permit deletion of single sites of protein-base contact at a cost of +1 to +2 kcal/mol. However, the introduction of any one incorrect natural base pair costs +6 to +13 kcal/mol in transition state interaction energy, the resultant of the following interdependent factors: deletion of one or two hydrogen bonds between the protein and a purine base; unfavourable steric apposition between a group on the protein and an incorrectly placed functional group on a base; disruption of a pyrimidine contact with the protein; loss of some crucial interactions between protein and DNA phosphates; and an increased energetic cost of attaining the required DNA conformation in the transition state complex. Eco RI endonuclease thus achieves stringent discrimination by both "direct readout" (protein-base contracts) and "indirect readout" (protein-phosphate contacts and DNA conformation) of the DNA sequence.