Elucidating mechanisms underlying fluctuations of sustained attention and their influence on memory

摘要 持续注意力（SA），即在长时间内保持专注于一项任务的能力，是一种 直接影响其他认知功能的基本认知过程，例如从讲座中学习或 从阅读。SA的波动是常见的，但其原因似乎是异质性的， 它们影响正在进行的信息处理和随后的记忆的方式还没有得到很好的理解。 一些研究者提出SA波动是由于随着任务的增加而增加的趋势 持续时间对走神（注意力漂移到内部思想或分心），由于失败的 执行控制过程。同样，执行控制的失败也往往会让注意力被 外部干扰。这个建议的主要目标是调查如何注意的方向（外部与。 内部）和控制水平相互作用，以确定SA的波动，以及它们如何影响当前的学习。在 目标1，申请人将调查两种类型的注意力缺失（外部分心和走神）， 可能发生在SA期间，包括它们随时间发生的速率以及它们各自如何影响随后的 记忆申请人将实现一种新颖的范例，其中任务相关的对象图像被呈现在 在更大的分散注意力的面部图像之上，思维探针被用来评估个体的注意力状态 当瞳孔反应被记录时，可以被视为任务中、外部分心或走神。主要 一个假设是，随着时间的推移，外部分心和走神的比率会增加， 执行控制力下降。此外，申请人将调查每个人的独特影响力 注意力缺失状态这项研究将是第一个涉及内部与外部失误， 注意在SA记忆性能使用瞳孔测量。在目标2a和2b中，fMRI方法， 沿着扫描仪瞳孔测量记录，将用于检查外部神经基础。 注意力分散与走神，并揭示这些注意力分散的不同神经机制。 状态影响记忆。这个目标将包括fMRI的注意力状态分类器分析的新应用 数据以及这些状态与行为和瞳孔测量措施的关系，以及创新动态 功能连接方法，以调查内部和网络之间的相互作用，引起SA 波动及其对记忆的影响。这项研究将提供深入了解背侧注意的作用 网络，默认模式网络和额顶控制网络，以及记忆成本 外部分心与走神，以获得更深入的了解神经机制，通过 哪种SA影响记忆。这个项目将大大增加我们对不同方式的理解， 哪一个SA可以被破坏，以及SA中的失误对随后的记忆的独特影响。因此 这些研究的结果可能反过来导致在识别正常人群中的SA缺陷方面的改进， 和各种临床疾病，并建议可能的方法，以如何解决这些问题。

Abstract Sustained attention (SA), the ability to maintain focus on a task over prolonged periods of time, is a fundamental cognitive process that directly impacts other cognitive functions, such as learning from a lecture or from reading. Fluctuations of SA are commonly observed, but their causes seem to be heterogenous, and the ways in which they influence ongoing information processing and subsequent memory are not well understood. Some researchers have proposed that SA fluctuations result from a growing tendency with increasing task duration towards mind-wandering (attention drifting towards internal thoughts or distractors), due to failure of executive control processes. Similarly, failures of executive control also tend to allow the capture of attention by external distractors. The main goal of this proposal is to investigate how the direction of attention (external vs. internal) and the level of control interact to determine fluctuations of SA, and how they affect current learning. In Aim 1, the applicant will investigate two types of attention lapses (externally distracted and mind-wandering) that can occur during SA, including the rates at which they occur over time and how they each influence subsequent memory. The applicant will implement a novel paradigm in which task-relevant object images are presented on top of much larger distracting face images, and thought probes are used to assess the individuals’ attention state as either on-task, externally distracted, or mind-wandering, while pupillary responses are recorded. The main hypothesis is that rates of external distraction and mind-wandering will increase over time as the maintenance of executive control diminishes. In addition, the applicant will investigate the distinct influence of each individual attention-lapse state on subsequent memory. This study will be the first to relate internal vs external lapses of attention during SA to memory performance using pupillometry measures. In Aims 2a and 2b, fMRI methodology, along with in-scanner pupillometry recordings, will be used to examine the neural underpinnings of external distraction vs mind-wandering during SA and to uncover the distinct neural mechanisms by which these attention states influence memory. This Aim will include novel application of attention-state classifier analyses of the fMRI data and how these states relate to the behavior and pupillometry measures, as well as innovative dynamic functional connectivity approaches to investigate the interplay within and between networks that gives rise to SA fluctuations and their effects on memory. This study will offer insights into the roles of the dorsal attention network, the default-mode network, and the fronto-parietal control network in SA, as well as the mnemonic costs of external distraction vs mind-wandering, to gain a deeper understanding of the neural mechanisms through which SA impacts memory. This project will substantially increase our understanding of the different ways in which SA can be disrupted and the unique influences that lapses in SA have on subsequent memory. Thus, the results of these studies may in turn lead to improvement in identifying SA deficits in both the normal population and in various clinical disorders, and suggest possible approaches as to how they may be addressed.