Neurobiological Bases of Economic Choice Behavior

经济选择是当个体仅仅基于主观判断做出选择时所观察到的行为。 例如，从餐厅菜单中选择偏好。选择行为是经济学的传统焦点， 心理学然而，从医学角度来看，经济选择也至关重要， 在患有额叶神经障碍和成瘾的患者中经常观察到缺陷。 从行为上看，证据表明，经济选择需要为可用的选项分配价值， 例如，菜单上的不同项目。然而，潜在的神经生物学机制仍然存在， 不太了解。来自病变、功能成像和电生理学的证据表明， 眶额皮质（OFC）可能在经济选择中发挥重要作用。这个项目的首要目标是 我们的建议是详细检查这个皮质区的贡献。这将通过记录 清醒的猴子在进行经济选择任务时的单个神经元活动。 在我们的实验中，猴子在不同数量的饮料中进行选择。他们的 选择为两种果汁的相对价值提供了行为测量。我们的初步研究表明 眶额皮层中的神经元对猴子对提供的和选择的果汁的价值进行编码，这表明选择 都是基于这个神经元群体的活动。这一观察提出了几个关键问题， 将在这里提出的实验中得到解决。首先，价值的神经元表示是否有所不同 取决于行为背景例如，神经元评估系统可能会适应 背景值范围，以利用最大的歧视权力，在某种程度上类似于视觉系统如何 适应环境光。第二，OFC神经元编码的是经济效用还是纯粹价值？选择通常 在涉及风险和成本的选项之间做出选择，两者都反映在预期效用中。如果选择是基于 在OFC的活动，我们预计在这方面的神经元编码的经济效用，区别于纯 值最后，尽管有大量关于额叶解剖学的文献， 来自值编码神经元的解剖学投射仍然不清楚。为了解决这个问题，我们将联合收割机 神经生理学记录的解剖学描记。本研究还将为PI提供机会， 学习组织学和解剖学技术，这将补充他的专业知识。

Economic choice is the behavior observed when individuals make choices solely based on subjective preferences¿for example out of a restaurant menu. Choice behavior is a traditional focus in economics and psychology. However, economic choice is also critically important from a medical perspective, as choice deficits are often observed in patients with neurological disorders of the frontal lobe and in addiction. Behaviorally, evidence indicates that economic choice entails assigning values to the available options¿for example, to different items on the menu. The underlying neurobiological mechanisms remain, however, poorly understood. Evidence from lesions, functional imaging and electrophysiology suggest that the orbitofrontal cortex (OFC) may play an important role in economic choice. The overarching goal of this proposal is to examine the contribution of this cortical area in detail. This will be achieved by recording the activity of individual neurons in awake monkeys while they engage in economic choice tasks. In our experiments, monkeys choose between different beverages offered in variable amounts. Their choices provide a behavioral measure for the relative value of the two juices. Our preliminary studies indicate that neurons in OFC encode the value monkeys assign to offered and chosen juices, suggesting that choices are based upon the activity of this neuronal population. This observation raises several critical questions that will be addressed in the experiments proposed here. First, does the neuronal representation of value vary depending on the behavioral context? For example, the neuronal valuation system might adapt to the contextual value range to exploit maximal discriminatory power, in a way similar to how the visual system adapts to ambient light. Second, do OFC neurons encode economic utility or pure value? Choices are often made between options that involve risks and costs, both reflected in the expected utility. If choices are based on the activity of OFC, we expect neurons in this area to encode economic utility, as distinguished from pure value. Finally, in spite of a substantial literature on the anatomy of the frontal lobe, what areas receive anatomical projections from value-encoding neurons remains unclear. To address this issue, we will combine anatomical tracings with neurophysiological recordings. This study will also provide the PI an opportunity to learn histological and anatomical techniques that will complement his portfolio of expertise.