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: 8234208
• 负责人: MATTHEW V CHAFEE
• 金额: $ 27.74万
• 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/8234208
• 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; relating to nervous system; research study; response; spatial relationship; success; visual receptive field; visual stimulus

Abstract 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.

摘要 人脑灵活地处理感觉输入，以提取最有用的信息并生成 考虑到当前的行为策略和目标，最有利的反应。这方面的计算灵活性 类型通常被称为执行控制，特别是当它涉及到大脑选择执行一种类型时 对另一个人的认知过程，以便在给定的背景下确定最佳的行动方案。我们有 对执行控制是如何通过大脑皮层的生理事件进行调节的理解有限 神经元。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20-30个单独分离的神经元在前额叶皮质(区46)的电活动 在猴子执行一项要求它们施加执行力的任务时，在后顶叶皮质(7a区) 对空间认知的控制。具体地说，猴子会将视觉刺激分配给不同的空间类别 根据我们在逐个试验的基础上指示和改变的变量分组标准(规则)。在这 任务中，我们提出了一条用作类别边界的线，并将空间类别定义为空间组 与线具有相同空间关系的位置--例如， 直线组成一个类别，所有指向右侧的点组成另一个类别。通过移动和旋转边界，我们 要求大脑灵活地将一组固定的空间位置重新分配给规则中的可选空间类别- 依赖方式，这需要大脑对空间分类施加执行控制，作为一种 认知和生理过程。我们的目标是发现行政控制如何控制空间 分类是在细胞水平上实现的，通过测量分布式神经中依赖于规则的变化 大脑在给定规则下分配给刺激的空间类别的表示。我们会 测试类别表征中依赖规则的变化将最先出现且最强的假设 在前额叶皮质。这将支持我们的假设，即前额叶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级，以及 提供了一些关于这种控制在细胞上实现的神经机制的第一个细节 水平。