Purging of memories from conscious awareness tracked in the human brain.
Purging of memories from conscious awareness tracked in the human brain.
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DOI：
10.1523/jneurosci.2640-12.2012
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发表时间：
2012-11-21
期刊：
影响因子：
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通讯作者：
Anderson MC
中科院分区：
文献类型：
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作者：
Levy BJ;Anderson MC
理解意识体验的神经基础及其调节是科学的基本目标。虽然最近的研究在识别意识体验的神经相关性方面取得了实质性进展，但人们仍然不清楚个体如何控制意识的内容。特别是，如果一个记忆已经进入意识状态，而它目前并不需要，那么它能从意识中清除吗？在这里，我们使用fMRI追踪了人类意识的相关性，并证明了一种下调机制的参与，该机制将意识意识中的内容清除。当个体试图阻止记忆的检索以响应提醒时，海马体的活动减少，正如先前所建立的那样。至关重要的是，通过对现象性意识的一次又一次的试验报告，我们发现海马激活的减少与记忆不自觉地侵入意识意识并需要清除的时刻特别相关。在记忆入侵期间，这种活动的下调似乎会破坏对不想要的内容的瞬间意识，重要的是，这预示着在以后的测试中记忆的回忆会受损。这些结果将意识的自主控制与意识相关的神经活动中可观察到的变化联系起来，从而为指导对意识控制的物理基础的研究提供了神经生物学模型。
Understanding the neural basis of conscious experience and its regulation are fundamental goals of science. While recent research has made substantial progress in identifying the neural correlates of conscious experiences, it remains unclear how individuals exert control over the contents of awareness. In particular, can a memory that has entered the aware state be purged from consciousness if it is not currently desired? Here we tracked the correlates of consciousness in humans using fMRI and demonstrated the involvement of a down-regulation mechanism that purges contents from conscious awareness. When individuals tried to prevent the retrieval of a memory in response to reminders, hippocampal activity was reduced, as previously established. Crucially, using trial-by-trial reports of phenomenal awareness, we found that this reduction of hippocampal activation was specifically associated with moments when a memory involuntarily intruded into conscious awareness and needed to be purged. This down-regulation of activity during memory intrusions appears to disrupt momentary awareness of unwanted contents and, importantly, predicts impaired recall of the memory on later tests. These results tie the voluntary control of phenomenal awareness to observable changes in neural activity linked to awareness, and so provide a neurobiological model for guiding inquiry into the physical foundations of control over consciousness.