Cognitive control and the functional organization of frontal cortex

描述（由申请人提供）：本研究计划的目标是促进我们对额叶皮层功能组织的理解，以及额叶区域之间的相互作用允许思想和行动的内部控制的方式，这种能力称为认知控制。拟议的实验测试的假设，即额叶的喙尾轴包括一个处理层次，从而更多的前区支持认知控制，涉及逐步更抽象的目标，计划和行动表示。首先，一组功能磁共振成像实验，使用阶乘逻辑，试图指定抽象的维度，定义区域差异沿着的头尾轴的额叶。几个实验已经证明了一个功能梯度沿着的喙尾轴的认知控制涉及更抽象的表征。然而，这些实验在抽象的定义上有所不同，包括领域一般性、时间抽象和规则复杂性。虽然这些抽象的维度不是相互排斥的，但它们也可以在受控的情况下独立地变化。因此，第一组功能磁共振成像实验利用这种独立性，提供了一个更明确的定义抽象，因为它涉及额叶功能。第二，层次系统要求上级处理器可以调节下级处理器，但反之亦然。如果把这种不对称性转化为额叶层次结构，那么它就预示着，额叶皮层特定区域的控制处理应该直接影响其所在区域的后部，而不是前部。因此，一条线的fMRI实验将使用有效的连接分析来测试（a）前额叶区域的认知控制加工是否可以调节后额叶区域的加工，（B）后额叶区域的认知控制加工是否可以影响前额叶区域的并发控制加工。第三，一组实验将调查额叶功能在学习和适应层次结构的规则集。一般来说，层次结构是支持学习新任务的有用结构，因为它们可以在多个抽象层次上表示相同的信息，因此可以为先验知识的应用提供接入点，例如通过类比。因此，一组实验测试是否假定的额叶层次结构反映了这种动态过程中的学习新的规则集，学习转移到新的任务，和应用程序的转换规则，现有的规则集。因此，在其目标，这个研究计划三角形的额叶层次组织的假设，通过测试三个不同的类别的预测，每一个产生于一个层次系统的假设。

DESCRIPTION (provided by applicant): The goal of this research program is to advance our understanding of the functional organization of frontal cortex and the ways in which interactions among frontal regions permit internal control of thought and action, an ability termed cognitive control. The proposed experiments test the hypothesis that the rostro-caudal axis of the frontal lobes comprises a processing hierarchy whereby more anterior regions support cognitive control involving progressively more abstract goals, plans, and action representations. First, a set of fMRI experiments, using factorial logic, seek to specify the dimensions of abstraction that define regional differences along the rostro-caudal axis of the frontal lobes. Several experiments have demonstrated a functional gradient along the rostro-caudal axis as cognitive control involves more abstract representations. However, these experiments have differed in their definition of abstraction, including domain generality, temporal abstraction, and rule complexity. Though these dimensions of abstraction are not mutually exclusive, they may also be independently varied under controlled circumstances. Thus, the first set of fMRI experiments take advantage of this independence to provide a more explicit definition of abstraction as it relates to frontal lobe function. Second, a hierarchical system requires that superordinate processors can modulate subordinate processors but not vice versa. Translated to a frontal hierarchy, this asymmetry predicts that control processing by a given region of the frontal cortex should directly influence regions posterior to but not anterior to its locus. Thus, a line fMRI experiments will use effective connectivity analysis to test whether (a) cognitive control processing in anterior frontal regions can modulate processing in posterior frontal regions, (b) whether cognitive control processing in posterior frontal regions can affect concurrent control processing by anterior frontal regions. Third, a set of experiments will investigate frontal lobe function during learning and adaptation of hierarchically structured rule sets. In general, hierarchies are useful structures for supporting learning of novel tasks because they can represent the same information at multiple levels of abstraction and so can provide access points for the application of prior knowledge, such as through analogy. Thus, a set of experiments test whether the putative frontal lobe hierarchy reflects such dynamics during learning of novel rule sets, the transfer of learning to new tasks, and the application of transformational rules to existing rule sets. Hence, across its aims, this program of research triangulates the hypothesis of a hierarchical organization of the frontal lobe by testing three different classes of predictions that each arises from an assumption of a hierarchical system.