Prefrontal network dynamics and top-down control of spatial representation

前额网络动力学和空间表征的自上而下控制

• 批准号: 7730744
• 负责人: MATTHEW V CHAFEE
• 金额: $ 27.61万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-20 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7730744
• 关键词: Area; Behavioral; Behavioral Paradigm; Biological Neural Networks; Brain; Categories; Cerebral cortex; Code; Cognition; Cognitive; Event; Experimental Designs; Goals; Grouping; Human; Individual; Joints; Knowledge; Left; Measurable; Measures; Mediating; Monkeys; Morphologic artifacts; Nature; Network-based; Neurons; Output; Parietal; Parietal Lobe; Pattern; Performance; Persons; Physiological; Physiological Processes; Play; Positioning Attribute; Prefrontal Cortex; Process; Property; Recruitment Activity; Relative (related person); Research; Role; Schizophrenia; Sensory Process; Signal Transduction; Stimulus; Stroke; System; Testing; Time; Training; Ursidae Family; Visual; Work; abstracting; base; cognitive function; design; executive function; flexibility; human disease; member; neuromechanism; nonhuman primate; public health relevance; relating to nervous system; research study; response; spatial relationship; success; visual receptive field; visual stimulus

DESCRIPTION (provided by applicant): The human brain processes sensory input flexibly to extract the most useful information and generate the most advantageous response given current behavioral strategies and goals. Computational flexibility of this type is often referred to as executive control, particularly when it involves the brain selecting to implement one cognitive process over another in order to determine the best course of action within a given context. We have a limited understanding of how executive control, as such, is mediated by physiological events in cortical neurons. To increase our knowledge of the cellular basis of executive control, I propose to simultaneously record the electrical activity of ensembles of 20-30 individually isolated neurons in prefrontal cortex (area 46) and in posterior parietal cortex (area 7a) of monkeys as they perform a task requiring them to exert executive control over spatial cognition. Specifically, monkeys will assign visual stimuli to alternative spatial categories according to a variable grouping criterion (rule) that we instruct and change on a trial-by-trial basis. In this task, we present a line that serves as a category boundary, and define spatial categories as groups of spatial positions that bear the same spatial relationship to the line - such that, for example, all points to the left of the line comprise one category, and all points to the right another. By shifting and rotating the boundary, we require the brain to flexibly reassign a fixed set of spatial positions to alternative spatial categories in a rule- dependent manner, and this requires the brain to exert executive control over spatial categorization as a cognitive and physiological process. Our objective is to discover how executive control over spatial categorization is implemented at a cellular level, by measuring rule-dependent changes in distributed neural representations of the spatial category to which the brain has assigned a stimulus under a given rule. We will test the hypothesis that rule-dependent changes in category representation will emerge first and be strongest in prefrontal cortex. This will support our hypothesis that prefrontal cortex sits above parietal cortex in a hierarchy of areas mediating executive control over cognitive processing in distributed cortical systems, and provide some of the first detail about the neural mechanisms by which this control is implemented at a cellular level. PUBLIC HEALTH RELEVANCE: The research described in this proposal investigates the neural mechanisms of executive control in prefrontal cortical networks of the nonhuman primate brain. Executive control refers to the capacity of the brain to selectively implement alternative cognitive processes on the basis of behavioral rules, goals or strategies. To understand how executive control is implemented by cortical neurons, we will record the electrical activity of groups of neurons in the prefrontal and posterior parietal cortex of monkeys as they perform a task in which rules govern spatial cognitive processing. Prefrontal and parietal cortexes are anatomically connected and jointly support spatial cognitive function. By discovering how rules modulate patterns of electrical activity associated with cognitive processing in this cortical network, we will be able to discover how executive control is implemented at a cellular level, and further determine whether prefrontal cortex plays a predominant role in mediating executive control. This in turn will help us understand the neural processes that may be disrupted to produce deficits in executive function in human diseases, such as prefrontal stroke, or schizophrenia.

描述（由申请人提供）：人脑灵活地处理感官输入，以提取最有用的信息，并根据当前的行为策略和目标生成最有利的反应。这种类型的计算灵活性通常被称为执行控制，特别是当它涉及大脑选择实施一种认知过程而不是另一种认知过程以确定给定上下文中的最佳行动方案时。我们对执行控制本身是如何由皮层神经元的生理事件介导的了解有限。为了增加我们对执行控制的细胞基础的了解，我建议同时记录猴子前额皮质（区域 46）和后顶叶皮质（区域 7a）中 20-30 个独立神经元的电活动，因为它们执行要求它们对空间认知施加执行控制的任务。具体来说，猴子会根据我们在逐次试验的基础上指导和改变的可变分组标准（规则）将视觉刺激分配给替代空间类别。在此任务中，我们提出一条线作为类别边界，并将空间类别定义为与线具有相同空间关系的空间位置组，例如，线左侧的所有点包含一个类别，右侧的所有点包含另一个类别。通过移动和旋转边界，我们要求大脑以规则依赖的方式灵活地将一组固定的空间位置重新分配给替代的空间类别，这要求大脑对空间分类作为认知和生理过程施加执行控制。我们的目标是通过测量大脑在给定规则下分配刺激的空间类别的分布式神经表征的规则相关变化，发现如何在细胞水平上实现对空间分类的执行控制。我们将检验这样一个假设：类别表征中的规则依赖性变化将首先出现，并且在前额叶皮层中最强。这将支持我们的假设，即前额皮质位于顶叶皮质之上，在分布式皮质系统中调节对认知处理的执行控制的区域层次结构中，并提供有关在细胞水平上实现这种控制的神经机制的一些初步细节。公共健康相关性：本提案中描述的研究调查了非人类灵长类动物大脑前额皮质网络中执行控制的神经机制。执行控制是指大脑根据行为规则、目标或策略选择性地实施替代认知过程的能力。为了了解皮质神经元如何实现执行控制，我们将记录猴子前额叶和后顶叶皮质中神经元组的电活动，因为它们执行规则控制空间​​认知处理的任务。前额叶和顶叶皮层在解剖学上是相连的，共同支持空间认知功能。通过发现规则如何调节与皮质网络中的认知处理相关的电活动模式，我们将能够发现执行控制是如何在细胞水平上实现的，并进一步确定前额叶皮层是否在调节执行控制中发挥主导作用。这反过来将帮助我们了解可能被破坏而导致人类疾病（例如前额叶中风或精神分裂症）执行功能缺陷的神经过程。