The Neural Basis of Decision-Making: Cortical & Subcortical Mechanisms

你更喜欢哪一个，12个月内赚20美元，还是13个月内赚22美元？大多数人会等 额外的一个月，以获得额外的2美元。365天后再问自己同样的问题：20美元，你更喜欢哪个？ 今天还是一个月后22美元现在大多数人会选择20美元的即时收益; 喜好坐在诊所里，大多数吸毒者都倾向于在一天的晚些时候避免吸毒。 几个小时后，面对一种立即可用的药物，他们的偏好发生了逆转。这些观察揭示了 人类通过比较奖励的主观价值来做出选择，而这些价值并不取决于 只取决于奖励有多大，而取决于何时收到奖励。满足感延迟的时间越长， 不那么令人满意的奖励出现。经验数据表明，这种可取性的下降发生在大多数 在短延迟时突然发生，并且随着延迟的增加而逐渐发生。也许同样有趣的是 基本上所有的脊椎动物似乎都表现出类似的模式。那么，神经系统 为延迟奖励设定主观价值的机制？ 对决策的神经生物学研究在很大程度上避免了这个问题。在本申请中，我们 建议将现有的神经生物学决策研究扩展到时间选择领域。我们 我建议进行这项研究与行为，生理和功能磁组合 共振成像技术，并测试两个假设，寻求寻求解释选择的时间： 标准生理模型和经济理论的主导双系统模型。我们特别 我建议测试这两种模型中的任何一种都可以解释后顶叶活动的假设 皮层和腹侧纹状体的神经元。 决策延迟的病理影响在疾病中普遍存在。延迟扭曲了 注意力缺陷障碍儿童、病态赌徒、吸毒者、吸烟者、 酗酒者可卡因和海洛因成瘾者尽管对延迟的异常敏感性控制了 尽管我们对所有这些患者群体的行为进行了研究，但对这种疾病的机制几乎一无所知。我们 我提出了一系列旨在阐明病理学基础的基本机制的实验， 做出不恰当的决策。

Which would you prefer, a gain of $20 in 12 months or of $22 in 13 months? Most people would wait the extra month to gain the extra $2. Ask yourself the same question 365 days later: which would you prefer, $20 today or $22 in a month? Now most people would select the immediate gain of $20; a reversal in preferences. Sitting in a clinic, most drug users state a preference for avoiding drug use later in the day. Hours later, confronting an immediately available drug, their preferences reverse. These observations reveal that humans make choices by comparing the subjective values of rewards and that these values depend not just on how large a reward is but when that reward will be received. The longer gratification is delayed; the less desirable a reward appears. Empirical data suggeststhat this decrease in desirability occurs most abruptly at short delays and more gradually as delays increase. Perhaps just as interesting is the observation that essentially all vertebrates appear to show a similar pattern. What then, is the neural mechanism that sets a subjective value on delayed rewards? Neurobiological studies of decision-making have largely avoided this issue. In this application we propose to extend existing neurobiological studies of decision-making into the domain of choice-in-time. We propose to undertake this study with a combination of behavioral, physiological and functional magnetic resonance imaging techniques and to test two hypotheses that seek seek to explain choice-in-time: a standard physiological model and the dominant two-system model of economic theory. Specifically, we propose to test the hypothesis that either of these models can account for the activity of the posterior parietal cortex and the ventral striatum under a range of conditions. Pathological influences of delays on decision making are pervasive in disease. Delays distort the decisions made by children with attention-deficit disorder, pathological gamblers, drug abusers, smokers, alcoholics, cocaine and heroin addicts. Despite the fact that an abnormal sensitivity to delays controls the behavior of all of these patient groups, almost nothing is known about the mechanism of this disorder. We propose a series of experiments aimed at elucidating the basic mechanism that underlies the pathological decision making that marks inappropriate choice-in-time.