A Role for Locus Coeruleus in Information Processing

蓝斑在信息处理中的作用

• 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
• 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
• 来源: https://reporter.nih.gov/project-details/8146159
• 关键词: Accounting; Acetylcholine; Adaptive Behaviors; Affect; Animals; Basic Science; Behavior; Behavioral; Belief; Biological; Brain; Brain Stem; Caliber; Cell Nucleus; Complex; Coupled; Data; Disease; Environment; Future; Goals; Human; Individual Differences; Lead; Macaca mulatta; Manuscripts; Maps; Measurement; Measures; Methods; Metric; Modeling; Monkeys; Neuromodulator; Neurons; Noise; Normal Range; Outcome; Pattern; Performance; Physiological; Play; Preparation; Probability; Problem Solving; Process; Psychophysics; Publishing; Pupil; Research Design; Role; Sensory; Signal Transduction; Task Performances; Techniques; Testing; Training; Uncertainty; Update; Work; base; behavior measurement; environmental change; experience; human subject; information processing; insight; interest; locus ceruleus structure; neuromechanism; neurophysiology; nonhuman primate; noradrenergic; novel; research study; response; theories

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.

决策常常依赖于对潜在结果的概率和价值的表述。然而，在动态环境中维护这些变量的精确表示是很困难的。大多数在这种环境中保持准确表示的策略在经历不可预测的结果后都会更新它们。这些方法的一个关键挑战是确定不可预测的结果对现有表示应该有多大的影响。原则上，这一决定应考虑到至少两种形式的环境变化。持续的环境随机性，或噪音，导致每个结果都不能很好地预测下一个结果，这表明每个新的结果对现有的表示应该只有最小的影响。另一种形式的可变性是由于突然的环境变化或变化点而发生的。这样的变化点可以使历史结果与未来的结果无关，这表明表征应该受到新结果的高度影响。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了相反的行动方针。先前的研究表明，人和动物在嘈杂和不断变化的环境中更新表征的能力几乎是最佳的，这表明大脑有一种利用环境可变性来分配影响新结果的机制。然而，人们对其潜在的神经机制知之甚少。一个突出的假说认为，脑干蓝斑核（LC）提供了一种不确定性信号，可用于自适应地调节传入的感觉信息对知觉加工的影响。然而，这一理论及其与更普遍的信念更新形式的关系还有待于实证检验。这项提案的目的是为我提供最先进的实验技术培训，结合定量行为和神经生理测量。这次培训将允许我测试LC编码与感知噪声和变化点相关的关键计算变量的假设，这些变量用于分配对传入信息的影响。所提出的实验是基于我之前在研究生工作中开发的行为和计算方法。第一个具体目的是表征瞳孔直径和LC活动之间的关系。第二个目的是测试在同一受试者执行表征更新任务时，LC活动是否反映了结果影响的行为和计算指标。总之，这些目标将为LC在复杂的适应性行为中的作用提供新的见解。