Hierarchies of spatiotemporal anticipation in the human brain

项目摘要 日常经验要求人类以分层的方式制定计划，因此他们可以预测视觉效果。 可能在未来几秒、几分钟、几小时或更长时间内发生的事件。例如，当走过 城市，个人必须跟踪他们的直接周围环境（例如，周围行人的移动）， 中间子目标（例如，沿着他们的路线的地标），以及长期目标（例如，最终目的地）。 尽管在行为中普遍存在这种等级化的预期，但目前还不清楚大脑如何同时 在多个时间尺度上预测事件。我们的目标是揭示分层的机制 大脑视觉系统中的预期信号，通过确定这些信号如何形成，它们代表什么， 他们是如何被更新的，以及他们如何引导面向未来的行为。这将通过功能 磁共振成像（fMRI），神经心理学研究，自然刺激，计算模型， 复杂的分析方法来表征大脑活动的动态。这些方法将决定 视觉系统产生分层预期信号的条件，内容和 这些信号的灵活性，它们是如何产生的，以及它们对行为的影响。目标1将确定如何 分层预期信号的形式和它们代表什么。我们假设这种等级化的预期 依赖于来自记忆系统的输入，由预先存在的图式告知，并且在视觉特征上是灵活的 和所代表的时间尺度。目标2将确定分层预期信号如何受到顶层- 下目标来模拟未来，以及这些信号如何与未来导向的视觉行为在一定范围内， 时间尺度。我们假设，视觉层次差异更新其预期信号时， 环境或目标发生变化，并通过将不同的情景联系起来，在新的情况下产生预测信号。 回忆最后，目标3将测试预期表征结构的竞争理论。我们 假设预期表征受到内部时间和语义关系的影响， 一个事件序列，并提出了一个计算模型，用于预测预期的事件表示学习 从一个时间结构的刺激。总之，这些发现将阐明视觉刺激的机制。 系统在多个时间尺度上形成并灵活地更新预期表示，以及这些 表征与自然主义条件下的预期行为有关。这些见解很重要，因为 期望有助于个体适应性行为，而视觉预期的破坏 可能会严重损害目标导向行为。因此，这项工作将阐明预测能力如何 未来的事件，以适应性地引导行为可能会受损后，损害不同部分的视觉 系统，包括高阶区域，其损伤与原发性视觉缺陷无关。统称 结果将提供实证检验的结构和发展的预期信号在整个视觉 等级制度，告知理论认为大脑是一个基本的预测器官。

PROJECT SUMMARY Everyday experience requires humans to make plans in a hierarchical fashion, so they can anticipate visual events that might occur seconds, minutes, hours, or longer in the future. For example, when walking through a city, individuals must track their immediate surroundings (e.g., the movement of pedestrians around them), intermediate sub-goals (e.g., landmarks along their route), and long-timescale goals (e.g., their final destination). Despite the ubiquity of such hierarchical anticipation in behavior, it is unclear how the brain can simultaneously anticipate events at multiple timescales. Our aim is to uncover the mechanisms underlying hierarchical anticipatory signals in the brain’s visual system, by determining how these signals form, what they represent, how they are updated, and how they guide future-oriented behavior. This will be accomplished with functional magnetic resonance imaging (fMRI), neuropsychological studies, naturalistic stimuli, computational models, and sophisticated analytic approaches for characterizing the dynamics of brain activity. These methods will determine the conditions under which the visual system generates hierarchical anticipatory signals, the content and flexibility of those signals, how they arise, and their consequences for behavior. Aim 1 will establish how hierarchical anticipatory signals form and what they represent. We hypothesize that such hierarchical anticipation depends on input from memory systems, is informed by pre-existing schema, and is flexible in the visual features and timescales represented. Aim 2 will determine how hierarchical anticipatory signals may be affected by top- down goals to simulate the future, and how these signals relate to future-oriented visual behavior at a range of timescales. We hypothesize that the visual hierarchy differentially updates its anticipatory signals when the environment or goals change, and generates predictive signals in novel situations by linking separate episodic memories. Finally, Aim 3 will test competing theories of the structure of anticipatory representations. We hypothesize that anticipatory representations are influenced by both temporal and semantic relationships within an event sequence, and propose a computational model for predicting anticipatory event representations learned from a temporally-structured stimulus. Together, the findings will elucidate the mechanisms by which the visual system forms and flexibly updates anticipatory representations at multiple timescales, and how these representations relate to anticipatory behavior in naturalistic conditions. Such insights are important because expectations are instrumental in allowing individuals to behave adaptively, and disruption of visual anticipation might broadly impair goal-directed behavior. This work will therefore shed light on how the capacity to anticipate upcoming events to adaptively guide behavior might be impaired following damage to different parts of the visual system, including higher-order areas whose damage is not associated with primary visual deficits. Together, the results will provide empirical tests of the structure and development of anticipatory signals across the visual hierarchy, informing theories that consider the brain to be a fundamentally predictive organ.