Dual Mechanisms of Cognitive Control

描述（由申请人提供）：本提案探讨认知控制的神经和心理机制。控制过程被认为是许多认知领域的重要组成部分，包括注意力、工作记忆、抑制、情景记忆、分类和决策。此外，认知控制功能受损是精神疾病（如精神分裂症、吸毒成瘾）和健康老龄化的主要组成部分。大量的研究表明，前额叶皮层（PFC）是认知控制的关键神经基质。然而，对认知控制机制的理论规范进展缓慢。我们提出的工作是我们之前在PFC功能及其与其他大脑结构的相互作用方面理解和开发明确的认知控制模型的努力的直接延伸。我们提出了认知控制以两种不同的模式运作的假设-主动和被动-每一种模式都由一套独立的机制提供服务。主动控制模式通过主动持续PFC表征的自上而下偏置效应为即将发生的事件做好认知系统的准备。反应性控制模式是根据需要进行的，使认知系统能够通过PFC的短暂再激活，或通过后皮层和海马体中存储的信息的检索，对强制性事件做出适当的反应。大多数认知任务的表现被认为依赖于主动和被动控制的混合，但对一种模式或另一种模式的偏见可能受到许多不同因素的影响，包括：a)任务情境的特定（通常是微妙的）特征；B)一种或另一种模式下的神经系统功能受损；c)认知能力和动机的个体差异。这些假设将在一系列综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）中进行测试，研究认知控制模式对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一个重要的理论进步，通过澄清控制认知是如何实现的原因和后果。更实际的是，这个项目有可能提供关于健康个体和临床人群在认知控制中遭受的短暂性失误和持续性损伤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.