Selection and updating of mental representations in working memory: A combined MEG and fMRI approach

工作记忆中心理表征的选择和更新：MEG 和 fMRI 相结合的方法

• 批准号: 71616496
• 负责人: Privatdozent Dr. Christoph Bledowski
• 金额: --
• 依托单位: Institut für Medizinische Psychologie (IMP)
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/71616496?language=en
• 关键词: Selection; updating; mental; representations; working

Working memory (WM) enables us to maintain and manipulate different kinds of information to guide future behaviour. It includes two components: short-term storage and executive processes that operate on the stored contents. The process of selecting relevant pieces of information amongst those held active in memory and the updating of the currently focused items are commonly considered as core executive processes of WM. Whereas prior studies have elucidated the mechanisms of shortterm storage and its dissociability from executive processes, both in single-cell recordings and in neuroimaging approaches using fMRI and MEG/EEG, the neural networks supporting different executive operations within WM have remained elusive. Here, two of these sub-processes of WM, selection amongst WM items and updating of the currently focused WM item, shall be investigated in a two-factorial combined fMRI and MEG study with healthy subjects. In surplus to the simple main effects, the proposed factorial design will yield evidence as to whether the two putative sub-processes interact at the neural level. Integration of spatial and temporal information obtained with fMRI and MEG, respectively, will allow for a localization of effects in both time and space and for tracking the signals' spatiotemporal evolution. In addition, the time courses of the source activations identified by fMRI-constrained MEG analysis shall be used to probe the dynamic coupling between distributed brain regions, characterising the timing and directedness of their communication.

工作记忆（WM）使我们能够保持和操纵不同类型的信息，以指导未来的行为。它包括两个组件：短期存储和对存储内容进行操作的执行过程。从记忆中激活的信息中选择相关信息的过程以及对当前关注项目的更新通常被认为是工作记忆的核心执行过程。尽管先前的研究已经阐明了短期存储的机制及其与执行过程的分离性，无论是在单细胞记录中还是在使用fMRI和MEG/EEG的神经成像方法中，支持WM中不同执行操作的神经网络仍然难以捉摸。在这里，两个WM，WM项目之间的选择和更新目前集中的WM项目，这些子过程中，应调查在两个因素相结合的功能磁共振成像和脑磁图研究与健康受试者。在盈余的简单的主效应，建议的析因设计将产生证据，以两个假定的子过程是否在神经水平上相互作用。分别用fMRI和MEG获得的空间和时间信息的整合将允许在时间和空间上定位效应并跟踪信号的时空演变。此外，通过fMRI约束MEG分析识别的源激活的时间过程应用于探测分布式脑区之间的动态耦合，表征其通信的时间和方向性。