Studies of Hierarchic Organization in Prefrontal Cortex

描述(由申请者提供)：PFC中介的认知控制过程允许通过偏向目标相关反应的选择来灵活行为。这里提出的研究试图检验关于RFC控制程序组织的两个相关假设。功能磁共振成像(FMRI)研究将识别RFC在选择反应的过程中处理不同水平表征的区域。这些水平被假设为基于表征指导选择的抽象性，范围从运动前皮质的具体特征(例如红色)到后外侧区域的更抽象的维度(例如颜色)，再到额叶的一般目标或背景(例如颜色命名任务)。随后，一项对RFC局灶性损害的神经科患者的研究以及经颅磁刺激(TMS)对局灶性破坏的研究将检验这些RFC区域的功能必要性和独立性。此外，这些数据与fMRI数据的功能连通性分析一起可以测试这样的假设，即这种代表性层次反映在RFC区域之间的关系中，在从上级区域到下级区域的处理流中例示。获得的有关RFC组织的基本知识可以为影响额叶的疾病提供重要的见解，并有助于制定指标化执行功能的直接临床评估。

DESCRIPTION (provided by applicant): PFC mediated cognitive control processes permit flexible behavior by biasing selection of goal-relevant responses. The research proposed here seeks to test two related hypotheses regarding the organization of RFC control processes. A functional magnetic resonance imaging (fMRI) study will identify regions of RFC processing different levels of representation en route to selecting a response. These levels are hypothesized to be individuated on the basis of the abstractness of the representation guiding selection, ranging from concrete features (e.g., red) in premotor cortex, to more abstract dimensions (e.g., color) in posterior lateral regions, to a general goal or context (e.g., color naming task) in frontal pole. Subsequently, a study of neurological patients with focal damage in RFC and a study of focal disruption by transcranial magnetic stimulation (TMS) will test the functional necessity and independence of these RFC regions. Furthermore, these data, along with functional connectivity analysis of the fMRI data, can test the hypothesis that this representational hierarchy is reflected in the relationship among RFC regions, instantiated in a flow of processing from superordinate to subordinate regions. Basic knowledge gained regarding the organization of RFC can provide important insights into disorders impacting the frontal lobes and toward the development of directed clinical assessments that index executive function.