Putting Priority Map Theory to the Test

描述（由申请人提供）：尽管人们普遍认为前额叶和后顶叶皮质（PFC/PPC）是灵活行动和有效感知所必需的，但在理解它们实现这些目标的控制机制方面存在根本性的差距。这种知识上的差距是一个关键问题，因为许多精神和神经疾病都源于执行控制的原发性功能障碍。长期目标是了解PFC和PPC对运动和感觉系统进行控制的机制。目前的建议的目的是测试一个新的模型，在PFC和PPC的活动如何形成优先空间的地图，标记在视野中的显着和相关的位置，然后可以用作执行控制信号的基础。偏见的机制可能涉及用于扫视规划的机制。该项目的中心目标是测试人类PFC和PPC的神经活动模式与优先图理论的预测一致的程度，包括优先图的功能组织，优先事项的性质以及优先级的表示。 竞争的优先事项。拟议的研究的理由是，更好地了解如何控制施加将导致一个强大的理论框架内，战略的理解精神疾病将发展。我们的目标将是测试，完善，并可能反驳，优先地图理论的原则，这将通过追求三个具体目标来实现：1）测试的假设，优先地图中的活动是不可知的是什么导致优先化; 2）测试的假设，优先地图中的活动编码的激励与多个优先事项;以及3）检验优先级图中的活动编码与多个优先级项目相关联的提示概率的假设。强有力的初步数据证明了申请人手中目标的可行性。几个候选人的优先权地图确定在额顶叶皮层使用新的地形图映射方法。在目标1下，候选优先级图中的延迟期活动和大脑活动的多变量模式在各种空间认知任务（例如，记忆力、注意力、计划）。在目标2下，额叶和顶叶皮层的行为测量和空间特异性活动与工作记忆中保持的位置的激励驱动的优先级成比例。在目标3中，工作记忆的表现与被保存的位置后来被探测的可能性成比例。该方法是创新的，因为它是高度程序化的;使用新的方法来对抗PFC和PPC的功能神经解剖学中的个体差异;用新的分析避开过去的推理弱点;并使用强大的方法来严格测试关键假设。这项研究意义重大，因为它有望测试一种重要的新的执行控制模型，并将提供对人脑发挥控制作用的机制的详细了解，这些机制的功能障碍模型可以作为神经病理学的原因和潜在治疗方法。

DESCRIPTION (provided by applicant): Despite the widespread appreciation that the prefrontal and posterior parietal cortices (PFC/PPC) are necessary for flexible action and efficient perception, there is a fundamental gap in understanding the control mechanisms by which they accomplish these goals. This gap in knowledge is a critical problem because a host of psychiatric and neurologic disorders stem from a primary dysfunction of executive control. The long-term goal is to understand the mechanisms by which the PFC and PPC exert control over motor and sensory systems. The objective of the current proposal is to test a new model of how activity in the PFC and PPC form maps of prioritized space that tag salient and relevant locations in the visual field, which can then be used as the basis of executive control signals. The mechanisms of bias are likely to involve mechanisms used for saccade planning. The central aim of the project is to test the extent to which the patterns of neural activity in the human PFC and PPC are consistent with predictions from the priority map theory, including the functional organization of priority maps, the nature of what is prioritized, and the representation of competing priorities. The rationale for the proposed research is that a better understanding of how control is exerted will lead to a strong theoretical framework within which strategies for the understanding of mental disease will develop. The objective will be to test, refine, and possibly refute, tenets of the priority map theory which will be accomplished by pursuing three specific aims: 1) test the hypothesis that the activity in priority maps is agnostic about what led to prioritization; 2) test the hypothesis that the activity in priority maps encodes the incentives associated with multiple prioritized items; and 3) test the hypothesis that the activity in priorit maps encodes the cue probabilities associated with multiple prioritized items. Strong preliminary data demonstrate the feasibility of aims in the applicant's hands. Several candidate priority maps were identified in frontoparietal cortex using novel topographical mapping approaches. Under Aim 1, both delay period activity and multivariate patterns of brain activity in candidate priority maps were remarkably similar, if not interchangeable, across a variety of spatial cognition tasks (e.g., memory, attention, planning). Under Aim 2, behavioral measures and spatially specific activity in frontal and parietal cortex scaled with the incentive driven priorites of locations maintained in working memory. Under aim 3, working memory performance scaled with the likelihood that maintained locations would be later probed. The approach is innovative because it is highly programmatic; uses novel approaches to combat individual differences in the functional neuroanatomy of the PFC and PPC; sidesteps past inferential weaknesses with novel analyses; and uses powerful methods to rigorously test key hypotheses. The proposed research is significant because it is expected to test an important new model of executive control and will provide a detailed understanding of the mechanisms by which the human brain exerts control, such that models of dysfunction of these mechanisms can be targeted as causes of and potential treatments for neuropathology.