德國科學家一項最新研究發現,睡眠有助將短暫記憶轉化為長期記憶。
先前研究顯示,短暫記憶存儲於大腦名為海馬體的部位,長期記憶存放於名為新皮層的部位,類似電腦內存和硬碟的功能。短時間內回想剛記住的內容對把短期記憶轉化為長期記憶具有重要作用。
清醒時,重複記憶內容的過程容易受幹擾,難以形成長期記憶。
法新社24日報導,德國呂貝克大學研究人員在最新一期《自然雜誌神經學專刊》發表的研究報告顯示,人在睡眠中「回想」記憶內容時不易受幹擾。
研究人員給24名志願者一些卡片,內容是動物和日常用品圖案。志願者記憶卡片內容同時,研究人員施放少許難聞的氣味。
四十分鐘後,研究人員要求12名志願者開始記憶另一些圖案稍微不同的卡片。記憶開始前,他們再次施放先前那種氣味,幫助志願者回憶第一批卡片內容。
另一半志願者開始記憶第二批卡片前睡了一會兒。其間,研究人員施放同一種難聞氣味。
實驗發現,一直保持清醒的志願者平均能回憶起60%第一批卡片內容,小睡一會兒的志願者記住的內容平均為85%。
研究報告首席作者蘇珊·戴克爾曼說:「根據腦成像數據,我們認為,睡眠最初數分鐘內,記憶內容就開始從海馬體轉移至新皮層。它產生了這種出人意料的結果。」
戴克爾曼說,大腦實際工作過程並非和電腦一模一樣。「人類記憶完全屬於動態。記憶並非以靜態方式在新皮層中『存檔』,而是在各種影響因素下不斷變化。」
回憶也不是簡單地「讀取」記憶內容,而是「一種重建過程,記憶在那一過程中可能發生變化、出現錯誤」。(生物谷Bioon.com)
生物谷推薦原文出處:
Nature Neuroscience doi:10.1038/nn.2744
Labile or stable: opposing consequences for memory when reactivated during waking and sleep
Susanne Diekelmann,Christian Büchel,Jan Born& Bj?rn Rasch
Memory consolidation is a dynamic process. Reconsolidation theory assumes that reactivation during wakefulness transiently destabilizes memories, requiring them to reconsolidate in order to persist. Memory reactivation also occurs during slow-wave sleep (SWS) and is assumed to underlie the consolidating effect of sleep. Here, we tested whether the same principle of transient destabilization applies to memory reactivation during SWS. We reactivated memories in humans by presenting associated odor cues either during SWS or wakefulness. Reactivation was followed by an interference task to probe memory stability. As we expected, reactivation during waking destabilized memories. In contrast, reactivation during SWS immediately stabilized memories, thereby directly increasing their resistance to interference. Functional magnetic resonance imaging revealed that reactivation during SWS mainly activated hippocampal and posterior cortical regions, whereas reactivation during wakefulness primarily activated prefrontal cortical areas. Our results show that reactivation of memory serves distinct functions depending on the brain state of wakefulness or sleep.