A Role for Locus Coeruleus in Information Processing

蓝斑在信息处理中的作用

基本信息

批准号：
8146159
负责人：
Matthew Nassar
金额：
$ 2.82万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-09-08 至 2013-09-07
项目状态：
已结题

项目摘要

Decisions often depend on representations about the probability and value of potential outcomes. However, maintaining accurate representations of these variables can be difficult in a dynamic environment. Most strategies for maintaining accurate representations in such an environment update them after experiencing unpredicted outcomes. A key challenge for these approaches is to decide how much influence that unpredicted outcomes should have on existing representations. In principle, this decision should take into account at least two forms of environmental variability. Persistent environmental stochasticity, or noise, leads each outcome to be a bad predictor of the next suggesting that each new outcome should have only a minimal influence on an existing representation. Another form of variability occurs due to sudden environmental changes, or change-points. Such change-points can render historical outcomes irrelevant to future ones, suggesting that representations should be highly influenced by a new outcome. Both forms of variability lead to deviations from expected outcomes, however the two types of variability suggest opposite courses of action. Previous work has shown that people and animals are capable of updating representations nearly optimally in noisy and changing environments, suggesting that the brain has a mechanism for using environmental variability to assign influence to new outcomes. However, little is known about the underlying neural mechanisms. One prominent hypothesis implicates the brainstem nucleus locus coeruleus (LC) in providing an uncertainty signal that can be used to adaptively adjust the influence of incoming sensory information on perceptual processing. However, this theory ¿ and its relationship to more general forms of belief updating ¿ has yet to be tested empirically. The goal of this proposal is to provide me with training on state-of-the-art experimental techniques that combine quantitative behavioral and neurophysiological measurements. This training will allow me to test the hypothesis that LC encodes key computational variables related to perceived noise and change-points that are used to assign influence to incoming information. The proposed experiments are based on behavioral and computational approaches that I developed previously in my graduate work. The first specific aim is to characterize the relationship between pupil diameter and LC activity. The second aim will test whether LC activity reflects behavioral and computational metrics of outcome influence in the same subjects while they perform a representation updating task. Together these Aims will provide new insights about the role of LC in complex, adaptive behavior.

决策通常取决于对潜在结果的概率和价值的表示，但是，在动态环境中，在这种环境中保持准确表示的大多数策略都会在经历不可预测的结果后更新它们，这是一个关键挑战。这些方法的目的是决定不可预测的结果对现有的表示有多大影响。原则上，该决定应考虑至少两种形式的环境变化，即持续的环境随机性或噪声，这些因素会导致每个结果都成为不良的预测因素。下一个表明，每个新的结果应该对现有的表征只有最小的影响，由于突然的环境变化或变化点，这种变化点可能会使历史结果与未来的结果无关，这表明表征。两种形式的变异性都会导致与预期结果的偏差，然而，这两种类型的变异性表明相反的行动方针，表明人和动物能够在嘈杂和环境中近乎最佳地更新表征。环境的变化表明大脑有一种机制然而，人们对潜在的神经机制知之甚少，即脑干蓝斑核（LC）提供了一种可用于自适应调整传入影响的不确定性信号。然而，这种理论是关于知觉处理的感觉信息。及其与更一般形式的信念更新的关系 ¿该提案的目标是为我提供结合定量行为和神经生理学测量的最先进实验技术的培训，使我能够测试 LC 编码关键计算的假设。与感知噪声和变化点相关的变量用于分配对传入信息的影响。所提出的实验基于我之前在研究生工作中开发的行为和计算方法，第一个具体目标是表征瞳孔直径之间的关系。和LC活动。将测试 LC 活动是否反映了同一受试者在执行表征更新任务时的结果影响的行为和计算指标，这些目标将共同提供关于 LC 在复杂、适应性行为中的作用的新见解。