Dual Mechanisms of Cognitive Control

描述(由申请者提供)：这项建议探索认知控制的神经和心理机制。控制过程被认为是许多认知域的重要组成部分，包括注意、工作记忆、抑制、情景记忆、分类和决策。此外，认知控制功能障碍是精神障碍(如精神分裂症、药物成瘾)和健康衰老的主要组成部分。大量研究表明，前额叶皮质(PFC)是认知控制的关键神经底物。然而，在认知控制潜在机制的理论规范方面进展缓慢。我们提出的这项工作是我们先前努力的直接延伸，目的是根据PFC功能及其与其他大脑结构的相互作用来理解和开发认知控制的显式模型。我们提出的假设是，认知控制以两种不同的模式运作--主动和被动--每种模式都有一套独立的机制。主动控制模式通过积极持续的PFC表征的自上而下的偏向效应，使认知系统为即将到来的事件做好准备。反应控制模式是在需要的基础上进行的，使认知系统能够通过短暂地重新激活PFC或通过检索存储在后部皮质和海马体中的信息来适当地对命令性事件做出反应。大多数认知任务的成绩被认为依赖于主动和反应控制的混合，但对一种或另一种模式的偏见会受到许多不同因素的影响，包括：a)任务情境的特定(有时是微妙的)特征；b)一种或另一种模式背后的神经系统功能受损；以及c)认知能力和动机的个体差异。这些假设将在一系列整合的行为和神经成像研究(使用最先进的功能磁共振成像方法)中得到验证，研究认知控制模式对广泛认知领域的大脑激活和表现的影响，包括年轻人和老年人，以及与个体差异变量的关系。这项工作的成功将代表着重大的理论进步，因为它澄清了认知控制是如何实现的原因和结果。更实际的是，该项目有可能提供关于健康个体和临床人群在认知控制方面的暂时性失误和持续性损害的神经和心理基础的关键信息。这些知识可以用来推动制定更有效的干预措施。

DESCRIPTION (provided by applicant): This proposal explores the neural and psychological mechanisms of cognitive control. Control processes are thought to be an important component of a number of cognitive domains, including attention, working memory, inhibition, episodic memory, categorization, and decision making. Moreover, impairments in cognitive control function are a major component of both psychiatric disorders (e.g., schizophrenia, drug addiction) and healthy aging. A large body of work suggests that the prefrontal cortex (PFC) is a key neural substrate of cognitive control. However, progress in theoretical specification of the mechanisms underlying cognitive control has been slow. The work we propose is a direct extension of our previous efforts to understand and develop explicit models of cognitive control in terms of PFC function and its interaction with other brain structures. We put forth the hypothesis that cognitive control operates in two distinct modes - proactive and reactive - where each is subserved by a separate set of mechanisms. The proactive control mode prepares the cognitive system for upcoming events through the top-down biasing effects of actively sustained PFC representations. The reactive control mode is engaged on as-needed basis, enabling the cognitive system to appropriately respond to imperative events via transient reactivation of PFC, or via retrieval of information stored in posterior cortex and hippocampus. Performance in most cognitive tasks is postulated to rely upon a mixture of proactive and reactive control, but biases towards one mode or another can be influenced by a number of different factors, including: a) specific (and often times subtle) characteristics of the task situation; b) impaired function in the neural systems underlying one mode or another; and c) individual differences in cognitive capabilities and motivation. These hypotheses will be tested in an integrated series of behavioral and neuroimaging studies (using state-of-the-art functional magnetic resonance imaging methods) examining effects of cognitive control mode on brain activation and performance across a wide range of cognitive domains, in both young and older adults, and in relation to individual difference variables. Success in this work would represent a significant theoretical advance, by clarifying the causes and consequences of how control over cognition is achieved. More practically, this project has the potential to provide critical information regarding the neural and psychological bases of both the transient lapses and sustained impairments in cognitive control suffered by both healthy individuals and clinical populations. Such knowledge could be used to drive the development of more effective interventions.