Doctoral Dissertation Research in DRMS: Boundedly optimal sampling for decisions under uncertainty

为了模拟个人在不确定性下的选择，理论家通常假设所做的选择使个人的效用最大化。 虽然这通常是对观察到的行为的一个很好的描述，但也有一些情况下，人们会根据相关的奖励概率来选择替代品。 这种概率匹配行为是次优的。 概率匹配行为和最优行为都将取决于决策可用的时间（更多的时间产生更多的最优决策），如果个体基于抽样算法进行选择。 在这个博士论文改进补助金中，PI将测试这样的算法是否对观察到的选择负责，此外，人们是否是最优次优的（即，为了验证这些假设，将根据实验对象在不确定性下在运动决策的速度和准确性之间进行权衡的灵活性以及通用决策过程如何跨越决策域来评估实验对象。然后测试受试者在认知压力下的决策是否恶化到概率匹配，正如所提出的算法预测的那样。最后，受试者将使用功能磁共振成像测试，以确定是否一个大脑结构代表预期效用所产生的不同来源的不确定性。 这项研究有望将人类作为理想代理人的模型与人类决策的既定失败和局限性相协调。

To model an individual's choices under uncertainty, theorists typically assume the choices made maximize the individual's utility. While frequently a good description of observed behavior, there are instances where people instead choose alternatives in proportion to their associated probabilities of reward. This probability matching behavior is sub-optimal. Probability matching behavior and optimal behavior would both result depending on the time available to make decisions (where more time produces more optimal decisions) if individuals base their choices on a sampling algorithm. In this Doctoral Dissertation Improvement grant, the PI will test whether such an algorithm is responsible for observed choices and, furthermore, whether people are optimally suboptimal (i.e., optimal in their decision regarding when to be more, or less, optimal.To test these hypotheses, experimental subjects will be assessed in terms of how flexible they are at making tradeoffs between speed and accuracy in motor decisions under uncertainty and how generic decision processes are across decision domains. Subjects are then tested for whether their decisions under cognitive stress deteriorate to probability-matching, as predicted by the proposed algorithm. Finally, subjects will be tested using fMRI to determine whether one brain structure represents expected utility arising from different sources of uncertainty. This research holds promise for reconciling models of humans as ideal agents with established failures and limitations of human decision-making.