學習後之介入活動對記憶形成的促進效果：探討時間因素對記憶提取及靜息態大腦功能性連結的影響

Facilitation of Memory Formation by Post-Learning Intervention: A Time-Dependent Effect in Recall and Brain Connectivity in Resting-State fMRI

王怡文(Yi-Wen Wang)

指導教授 ： 周泰立

共同指導教授 ： 梁庚辰(Keng-Chen Liang)

國立臺灣大學/理學院/心理學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.10428

摘要

記憶固化假說認為，新習得的記憶痕跡隨時間而逐漸穩定，因此在學習活動過後不久，記憶處於較不穩定的狀態，也較易於被減弱或加強。本研究在目標學習之後加入介入學習，並操弄兩學習活動之間的時間間隔（立即或延遲），以測試立即介入或延遲介入對記憶固化影響的差異，藉此觀察記憶固化期間，海馬到大腦皮質間連結隨時間的變化特性。記憶固化期間，主要是由海馬引導先前學習經驗在新皮質區域中重現。過去研究發現，左側額葉下回（LIFG）和左側頂葉下部（LIPL）與記憶登錄及提取有關，且登錄與提取時的腦部活動具有相似性；然而介於記憶登錄及提取之間的記憶固化活動，則缺乏相關的人類研究。本研究之貢獻在於彌補此缺憾，提供記憶固化期間海馬、左側額葉下回和左側頂葉下部三者間的互動證據，藉由靜息態功能性連結，觀察海馬與新皮質間的互動，並以認知作業期間的功能性磁振造影，觀察記憶登錄及提取的腦部活動。本研究發現(1)立即介入比延遲介入更能有效地加強目標學習之記憶固化過程；(2)左側額葉下回在記憶登錄時的活動，與記憶固化期間海馬到額葉下回的互動有關，並藉此影響海馬與左頂葉下部間的互動。

關鍵字

記憶 ； 固化 ； 靜息態功能性磁振造影 ； 功能性連結

並列摘要

Memory consolidation hypothesis states that a newly-acquired memory trace stabilizes overtime, thus a memory trace is labile and could be easily disrupted or improved shortly after learning activity. This study used the time-dependent (delayed versus immediate) intervention to probe the difference between the immediately affected and later affected memory consolidation, in order to show the time-dependent nature of connectivity change from the hippocampus to cortical regions during memory consolidation. During memory consolidation, the hippocampus guides the replay of prior learning events across the neocortical regions. Previous studies have related the left inferior frontal gyrus (LIFG) and the left inferior parietal lobule (LIPL) to memory encoding and retrieval, or have found similar patterns of brain activities between encoding and retrieval in these regions. The present study bridges the gap between encoding and retrieval among previous human studies, and shows evidence of the interaction among the hippocampus, the LIFG and the LIPL during memory consolidation. This study used resting-state functional connectivity to observe hippocampal-neocortical interaction, and task-related fMRI to observe the brain activity during encoding and retrieval. Findings in this study suggest that (1) the process of memory consolidation for the target learning may be more effectively enhanced by the immediate intervening learning as compared to the delayed intervening learning; (2) the activity of the LIFG during encoding may be related to the hippocampal-LIFG interaction during memory consolidation, and in this way contributes to the hippocampal-LIPL interaction.

並列關鍵字

memory ； consolidation ； resting-state fMRI ； functional connectivity

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