ABSTRACT

It is important for mental health to be able to control unwanted intrusive memories. Previous studies suggest that middle frontal gyrus (MFG) down regulates pathways underlie the suppression of retrieval of general memories. However, the neural basis of motivated forgetting of autobiographical memories is unclear. Therefore, this study used two samples to explore the neural mechanisms of motivated forgetting of self-referential memories. Every participant provided 40 life events (20 negative and 20 neutral) from their past personal experience, and then completed the Think/No-Think task while undergoing functional magnetic resonance imaging (fMRI). The first sample showed a significant reduction in recall in the No-Think condition relative to the Think condition. Attempting to exclude negative autobiographical memories from awareness was associated with increased activity in the right MFG, superior frontal gyrus (SFG), and inferior frontal gyrus (IFG), while reduced activity was observed in the bilateral Brodmann areas BA18 and BA19, bilateral medial prefrontal cortex (mPFC), bilateral precuneus, bilateral post cingulate cortex (PCC), the left parahippocampus, and the left hippocampus. Functional connectivity analyses showed that the right MFG projected into the bilateral mPFC, bilateral precuneus, and bilateral middle occipital gyrus (MOG) for negative autobiographical memories. The second sample replicated the results of the first sample at both the behavioral and brain levels. These results suggest that retrieval suppression of autobiographical memories involve the pathway between the MFG and the mPFC and precuneus to exclude self-referential memories. These results reveal how people engage in motivated forgetting of negative events in their daily lives.

摘要

能够控制不需要的侵入性记忆对心理健康很重要。以前的研究表明，额中回 (MFG) 下调通路是抑制一般记忆检索的基础。然而，自传体记忆的动机性遗忘的神经基础尚不清楚。因此，本研究使用两个样本来探索自我参照记忆的动机性遗忘的神经机制。每个参与者根据他们过去的个人经历提供 40 个生活事件（20 个消极和 20 个中性），然后在进行功能磁共振成像 (fMRI) 的同时完成思考/不思考任务。第一个样本显示，与思考条件相比，不思考条件下的召回率显着降低。试图从意识中排除负面自传记忆与右侧 MFG、额上回 (SFG) 和额下回 (IFG) 的活动增加有关，而在双侧布罗德曼区 BA18 和 BA19、双侧内侧前额叶中观察到活动减少皮质 (mPFC)、双侧楔前叶、双侧扣带回后皮质 (PCC)、左侧海马旁和左侧海马体。功能连通性分析表明，右侧 MFG 投射到双侧 mPFC、双侧楔前叶和双侧枕中回 (MOG)，用于负性自传体记忆。第二个样本在行为和大脑水平上复制了第一个样本的结果。这些结果表明，自传体记忆的检索抑制涉及 MFG 和 mPFC 和楔前叶之间的通路，以排除自我参照记忆。这些结果揭示了人们在日常生活中如何有动机地忘记负面事件。