The Study of Task-Level Control Signals Using fMRI

利用功能磁共振成像研究任务级控制信号

• 批准号: 6906426
• 负责人: STEVEN E. PETERSEN
• 金额: $ 36.34万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6906426
• 关键词: auditory stimulus; behavior test; bioimaging /biomedical imaging; brain mapping; clinical research; cognition; frontal lobe /cortex; functional magnetic resonance imaging; human subject; image processing; magnetic resonance imaging; memory; method development; neural information processing; neuroanatomy; neurosciences; stimulus /response; visual stimulus; young adult human (21-34)

DESCRIPTION (provided by applicant): A major issue in cognitive neuroscience is how specific neural pathways are organized for task performance. The major hypothesis of this proposal is that task-level control is implemented, in part, by activity sustained across task trials, and can be studied using fMRI. This hypothesis is addressed through 3 Specific Aims. Specific Aim 1: To refine paradigm designs and analysis methods for separating sustained and transient fMRI signals. The main hypothesis is that the mixed block/event related paradigm can be optimized for the accurate and sensitive identification of sustained "control" signals from transient "trial-related" fMRI signals. Specific Aim 2: To characterize the functional attributes of different regions exhibiting sustained activity across trials. Three general hypotheses will be tested: 1) Some regions will exhibit sustained activity across a wide range of tasks, implicating them in general control functions; 2) In spite of this commonality, manipulation of separable aspects of control (e.g., input or response selection) will differentially affect specific subsets of these regions; 3) Some regions will show sustained activity related to specific task domains, implicating them as sources of domain specific control, or as sites at which control signals affect ongoing trial-related processing. Specific Aim 3: To use properties of sustained signals to address issues specific to memory retrieval. Several episodic retrieval studies have shown activation of right frontal regions, and it has been proposed that this activity may be related to "retrieval mode". Two related hypotheses are tested: 1) Right frontal sustained activity will be found across conditions that demand "re-collective effort" or "re-collective mode"; 2) The right frontal sustained activity will not be specific to "recollection", but will also be present when complex retrieval constraints are placed at "intermediate levels" between recollection and familiarity. As a group, these studies should improve our understanding of task control processes in the brain. Several psychiatric and neurological diseases (e.g., Tourette's syndrome, frontal lobe strokes) have been related to deficits of control; a deeper understanding of the neural mechanisms related to control processes may allow more specific diagnostic, prognostic, or rehabilitative approaches to these difficulties than currently exist.

描述（由申请人提供）：认知神经科学的一个主要问题是如何组织特定的神经途径以进行任务绩效。该提案的主要假设是，任务级控制是通过在任务试验中进行的活动来部分实施的，并且可以使用fMRI进行研究。该假设是通过3个特定目标解决的。特定目的1：用于优化范式设计和分析方法，用于分离持续和瞬态fMRI信号。主要的假设是，可以优化混合块/事件相关的范例，以确定来自瞬态“瞬态”试验“ FRIM相关” fMRI信号的持续“控制”信号。特定目的2：表征不同区域的功能属性，这些区域在试验中表现出持续活动。将检验三个一般假设：1）某些区域将在各种任务中表现出持续的活动，这将它们牵涉到一般控制功能中； 2）尽管存在这种共同点，但对控制的可分离方面（例如，输入或响应选择）的操纵将差异地影响这些区域的特定子集； 3）某些区域将显示与特定任务域相关的持续活动，将它们视为特定域控制的来源，或者作为控制信号影响正在进行的试验相关处理的站点。特定目的3：使用持续信号的属性来解决内存检索特定的问题。几项发作的检索研究表明，右额叶区域激活，并提出该活动可能与“检索模式”有关。测试了两个相关的假设：1）在要求“重新努力”或“重新集体模式”的条件下，将发现右额叶持续活动； 2）右额叶持续活动将不是“回忆”的特定，但是当复杂的检索约束位于回忆和熟悉度之间的“中间水平”时，也将存在。作为一个小组，这些研究应提高我们对大脑任务控制过程的理解。几种精神病和神经系统疾病（例如，图雷特综合症，额叶中风）与控制缺陷有关。对与控制过程相关的神经机制有更深入的了解可以使这些困难更具体的诊断，预后或康复方法。