Kim Hongkeun
Department of Rehabilitation Psychology, Daegu University, Gyeongsan-si, Republic of Korea.
Imaging Neurosci (Camb). 2024 Oct 22;2. doi: 10.1162/imag_a_00321. eCollection 2024.
Recent meta-analytic evidence has underscored the significant role of the default mode network (DMN) in facilitating item word encoding. This study builds on this finding through a comprehensive meta-analysis of fMRI-based subsequent memory studies that use words as stimuli. The results highlight several key functions within the DMN. Firstly, the dorsomedial prefrontal cortex (dmPFC) subsystem of the DMN plays a pivotal role in enhancing successful word encoding, suggesting its vital involvement in the semantic processing of incoming verbal information. Secondly, the utility of the dmPFC subsystem extends beyond item word encoding to associative word encoding tasks, demonstrating its broad applicability in verbal information encoding. Thirdly, regions within the left inferior frontal cortex, a core component of the dmPFC subsystem, show increased activity during associative compared to item word encoding, emphasizing their role in integrating verbal information with contextual details. Contrary to previous research that linked the DMN with encoding interference-often attributed to the core subsystem's tendency for mind-wandering-this study highlights the facilitative role of the dmPFC subsystem in memory encoding. The contrasting roles of the DMN subsystems, both interfering and facilitating, challenge traditional views and advocate for a more nuanced understanding of the network's role in memory encoding.
近期的荟萃分析证据强调了默认模式网络(DMN)在促进项目单词编码方面的重要作用。本研究基于这一发现,对以单词为刺激的基于功能磁共振成像(fMRI)的后续记忆研究进行了全面的荟萃分析。结果突出了DMN内的几个关键功能。首先,DMN的背内侧前额叶皮质(dmPFC)子系统在增强成功的单词编码中起关键作用,表明其在处理传入言语信息的语义过程中至关重要。其次,dmPFC子系统的作用不仅限于项目单词编码,还扩展到联想单词编码任务,证明了其在言语信息编码中的广泛适用性。第三,作为dmPFC子系统核心组成部分的左侧额下回内的区域,与项目单词编码相比,在联想编码期间显示出活动增加,强调了它们在将言语信息与上下文细节整合中的作用。与之前将DMN与编码干扰联系起来的研究(通常归因于核心子系统的心不在焉倾向)相反,本研究强调了dmPFC子系统在记忆编码中的促进作用。DMN子系统的干扰和促进这两种截然不同的作用,挑战了传统观点,并倡导对该网络在记忆编码中的作用有更细致入微的理解。