Investigation of the control and monitoring of task sequences

描述（由申请人提供）：许多日常任务需要多个目标和子目标的序列。例如，制作三明治的目标可能包含烤面包和涂抹调味品的子目标，这些子目标本身由子目标序列组成（例如，拿刀，打开罐子等）。我们灵活地引导这些行为的能力被称为认知控制，这是额叶皮层的主要功能。最近的研究表明，额叶皮层是沿着喙尾轴组织起来的，以控制不同抽象层次（目标到子目标）或层次上的认知任务。最 然而，这项工作中，使用非顺序的任务，因此，它只是假设类似的控制机制将支持分层控制的任务序列。这就留下了至少三个对我们理解额叶和认知控制功能至关重要的问题，通常是：1）额叶皮层的吻尾组织是否支持任务序列的分层控制; 2）在整个任务序列中，控制和监控的动态是什么; 3）任务序列的控制如何随着学习而变化。这三个问题将在我们的三个目标中得到解决，通过使用功能磁共振成像（fMRI）来研究以下假设：1）任务序列的层次控制是由额叶皮层的吻尾组织支持的; 2）监控将以持续的方式发生，（自始至终）或以短暂的方式（在开始/结束时）熟悉的任务序列;和3）监测将从在新序列上以持续的方式发生转变为在熟悉序列中的序列边界处瞬时发生学习。对任务序列的监控和控制的深入了解将是理解我们如何执行日常任务的基础。这种理解对于额叶功能障碍或损害的患者的生活质量尤其重要。这类患者通常不能独立生活，因为他们在计划和监测通常需要的任务序列方面有困难。

DESCRIPTION (provided by applicant): Many everyday tasks require sequences of multiple goals and subgoals. For example, the goal of making a sandwich may contain the subgoals of toasting the bread and spreading a condiment, which themselves consist of sequences of subgoals (e.g. getting a knife, opening the jar, etc.). Our ability to guide these actions flexiblyis known as cognitive control, and this is a primary function of the frontal cortex. Recent research has suggested that the frontal cortex is organized along the rostrocaudal axis to control cognitive tasks at different levels of abstraction (goals to sub-subgoals), or hierarchically. Most of this work, however, used non-sequential tasks; therefore, it has been only assumed that similar control mechanisms will support hierarchical control over sequences of tasks. This leaves at least three unanswered questions fundamental to our understanding of frontal lobe and cognitive control function, generally: 1) does the rostrocaudal organization of frontal cortex support hierarchical control of task sequences; 2) what are the dynamics of the control and monitoring throughout task sequences; and 3) how does the control of task sequences change with learning. These three questions will be addressed across our three aims by using functional magnetic resonance imaging (fMRI) to investigate the following hypotheses: 1) the hierarchical control of task sequences is supported by the rostrocaudal organization of frontal cortex; 2) monitoring will occur either in a sustained manner (throughout) or in a transient manner (at the beginning/end) for familiar task sequences; and 3) monitoring will transition from occurring in a sustained fashion over novel sequences to occurring transiently at sequence boundaries in familiar sequences with learning. The insight into the monitoring and control of task sequences that will be gained will be fundamental to the understanding of how we perform everyday tasks. This understanding is particularly crucial to the quality of life of those patients who have fronta lobe dysfunction or damage. Such patients often cannot live independently because they have trouble planning and monitoring the task sequences that are commonly required.