Human Cerebellar Function in Multiple Task Domains

项目摘要 这个项目的目标是扩展我们对小脑的理解，特别是， 结构有助于人类认知。不同的研究提供了令人信服的证据， 小脑不仅参与感觉运动控制，而且还有助于一系列认知功能。 例如，神经影像学文献已经产生了小脑的地图，其表现出稳定的功能性变化。 组织，大部分小脑皮质显示血液动力学变化，不能归因于 运动此外，小脑障碍患者在任务评估方面表现出行为障碍 认知和情感处理。然而，我们对小脑功能作用的理解， 认知领域仍然是基本的：功能假说要么主要是描述性的，要么是有针对性的 以一种相对狭窄的、特定任务的方式来解释小脑的功能。该研究计划概述在 这个建议旨在解决这个问题，寻求发展一个小脑的机制帐户， 功能从理论上讲，这项工作将由一个新的假设指导，即小脑是必不可少的 对于需要内部表示的连续变换或CoRT（连续 代表性变换）。这一假说提供了一个粗略的解释， 支持不同任务领域的性能。在感觉运动控制的背景下，CoRT将需要 将肢体从一个位置移动到另一个位置并预测感觉所需的计算 这一运动的后果。在其他任务领域中， 表征可以优化预期行为;例如，感知经常涉及内部 转换的感官输入，以占非典型的观点，社会判断可能会受益 不断模仿另一个人的预期动作。该研究计划将涉及 行为、计算和神经影像学研究的综合使用。一个主要组成部分， 行为工作将集中在脊髓小脑共济失调（SCA）的个人表现。这项工作将 涉及跨越广泛任务领域的传统现场实验，以测试CoRT假设， 以及一个雄心勃勃的在线测试计划。通过SCA支持推动的外展计划 网络和与国际研究团队的合作，在线程序应该产生一个 一个独特的数据库，提供功能假设的有力测试，并检查 行为表现、病因学和临床评级，并将这些指标与区域特异性病理学联系起来 在小脑中。第二个主要组成部分将建立在最近对健康年轻人的神经影像学工作的基础上 通过使用大电池， 的任务。这一方法将被用来探索对功能图组织的限制， 开发皮质-小脑连接模型，并检查学习过程中的变化。作为 随着神经心理学的研究，神经影像学研究将产生一个丰富的数据库，以评估不同的 功能假设，以及建立与非典型人群比较的规范。 !

PROJECT SUMMARY The goal of this project is to extend our understanding of the cerebellum, and in particular, how this subcortical structure contributes to human cognition. Diverse lines of research provide compelling evidence that the cerebellum is not only involved in sensorimotor control, but also contributes to a range of cognitive functions. For example, the neuroimaging literature has produced maps of the cerebellum that exhibit a stable functional organization, with much of the cerebellar cortex showing hemodynamic changes that cannot be attributed to movement. Moreover, patients with cerebellar disorders exhibit behavioral impairments on tasks assessing cognitive and affective processing. However, our understanding of the functional role of the cerebellum in cognitive domains remains rudimentary: Functional hypotheses have either been largely descriptive or targeted to account for cerebellar function in a relatively narrow, task-specific manner. The research program outlined in this proposal is designed to address this issue, seeking to develop a mechanistic account of cerebellar function. Theoretically, the work will be guided by a novel hypothesis, namely that the cerebellum is essential for processing that requires the continuous transformation of an internal representation, or CoRT(continuous representational transformation). This hypothesis offers a parsimonious account of how the cerebellum supports performance in diverse task domains. In the context of sensorimotor control, CoRT would entail computations required to move a limb from one position to another and to anticipate the sensory consequences of that movement. In other task domains, the continuous transformation of an internal representation may optimize anticipatory behavior; for example, perception frequently involves the internal transformation of the sensory input to account for atypical viewpoints, and social judgments may benefit continuously simulating the intended actions of another individual. The research program will involve the integrated use of behavioral, computational, and neuroimaging studies. One major component of the behavioral work will focus on the performance of individuals with spinocerebellar ataxia (SCA). This work will involve traditional on-site experiments spanning a broad range of task domains to test the CoRT hypothesis, as well as an ambitious on-line testing program. Through an outreach program facilitated by SCA support networks and collaborations with an international team of researchers, the on-line program should produce a unique database to provide well-powered tests of functional hypotheses, and examine relationships between behavioral performance, etiology, and clinical ratings, and relate these measures with region-specific pathology in the cerebellum. A second major component will build on recent neuroimaging work with healthy young adults that has provided a comprehensive functional map of the human cerebellum though the use of a large battery of tasks. This approach will be used to explore constraints on the organization of the functional map by developing models of cortico-cerebellar connectivity and examining changes over the course of learning. As with the neuropsychological studies, the neuroimaging studies will yield a rich database to evaluate different functional hypotheses, as well as establish norms for comparison with atypical populations. !