Neurobiological Bases of Economic Choice Behavior

经济选择是当个人完全基于主观作出选择时观察到的行为 偏好？例如，从餐厅菜单中选择。选择行为是经济学和经济学中的一个传统焦点 心理学。然而，从医学的角度来看，经济选择也是至关重要的，因为选择 额叶神经功能障碍患者和成瘾患者常可观察到缺陷。 在行为上，有证据表明，经济选择需要为可用选项赋值。 例如，添加到菜单上的不同项目。然而，潜在的神经生物学机制仍然存在， 人们对此知之甚少。损伤、功能成像和电生理学的证据表明 眼眶额叶皮质(OFC)在经济选择中可能起着重要作用。这件事的首要目标是 建议是详细研究这一皮质区域的贡献。这将通过记录 清醒的猴子在从事经济选择任务时个体神经元的活动。 在我们的实验中，猴子在提供不同量的不同饮料之间进行选择。他们的 选择为两种果汁的相对价值提供了一种行为衡量标准。我们的初步研究表明 OFC中的神经元编码猴子分配给所提供和选择的果汁的值，这表明选择 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解决。首先，价值的神经元表征是否有所不同？ 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，以利用最大的区分力，以类似于视觉系统如何 适应环境光。其次，OFC神经元编码的是经济效用还是纯粹的价值？选择往往是 在涉及风险和成本的选择之间做出的选择，两者都反映在预期效用中。如果选择是基于 关于OFC的活动，我们预计这一区域的神经元将编码经济效用，与纯 价值。最后，尽管有大量关于额叶解剖的文献，但哪些区域 来自编码价值的神经元的解剖学投射仍然不清楚。为了解决这个问题，我们将结合 有神经生理学记录的解剖痕迹。这项研究也将为PI提供一个机会 学习组织学和解剖学技术，这将补充他的专业知识组合。

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.