Functional Connectivity During Working Memory Maintenance

描述（由申请人提供）：本研究计划的长期目标是进一步了解工作记忆（WM）的神经基础。具体来说，这个建议的目标是表征网络的功能连接的大脑区域介导的视觉WM维护和确定他们的相互作用的行为意义。视觉工作记忆的许多理论都认为，当环境中不再能获得与行为相关的知觉信息时，前额叶皮层（PFC）会向后部视觉联想区提供自上而下的信号，以保持知觉信息的激活。然而，这种相互作用存在的证据是有限的和间接的。在这个提议中概述的实验将使用事件相关的功能磁共振成像来测量受试者执行WM任务时整个大脑的活动水平。最近开发的多变量分析程序，然后将被应用到数据，以检查区域间的相互作用，在WM的组成阶段。第一个实验将试图确定这些相互作用的强度和性质是否与行为表现有关。第二个和第三个实验将评估WM系统可以动态调整其功能连接配置文件，以适应增加的记忆负荷或克服分心的机制。

DESCRIPTION (provided by applicant): The long-term objective of this research plan is to further our understanding of the neural basis of working memory (WM). Specifically, the goals of this proposal are to characterize the network of functionally connected brain regions mediating visual WM maintenance and determine the behavioral significance of their interactions. Many theories of visual WM postulate the prefrontal cortex (PFC) provides top-down signals to posterior visual association areas in order to keep behaviorally relevant perceptual information activated when it is no longer accessible in the environment. However, evidence for the existence of this interaction is limited and indirect. The experiments outlined in this proposal will use event-related functional magnetic resonance imaging to measure activity levels throughout the brain as subjects perform WM tasks. A recently developed multivariate analysis procedure will then be applied to the data to examine inter-regional interactions during the component stages of WM. The first experiment will seek to determine whether the strength and nature of these interactions is related to behavioral performance. The second and third experiments will assess the mechanisms by which the WM system can dynamically adapt its functional connectivity profile to accommodate increased memory load or overcome distraction.