Hippocampal Immediate Poststimulus Activity in the Encoding of Consecutive Naturalistic Episodes
Hippocampal Immediate Poststimulus Activity in the Encoding of Consecutive Naturalistic Episodes
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DOI：
10.1037/a0033558
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发表时间：
2013-11-01
影响因子：
4.1
通讯作者：
Dudai, Yadin
中科院分区：
文献类型：
--
作者：
Ben-Yakov, Aya;Eshel, Neetai;Dudai, Yadin
在叙事情节的编码中，海马表现出时间锁定到刺激偏移的记忆预测活动。然而，在真实的生活中，事件通常是连续发生的，这就提出了一个问题，即一个事件的即时离线处理如何受到另一个事件的影响。为了解决这个问题，参与者在功能性磁共振成像扫描仪中观看了简短的叙事电影片段。每个片段之后立即是一个额外的、不相关的片段;一个视觉混乱的片段，背景听觉噪音;或一个固定交叉。研究结束后20 mm，在扫描仪外进行线索回忆测试，测试剪辑要点的记忆。海马体对每个片段的偏移做出反应，即使第二个片段是立即连续出现的，这表明海马体将每个简短的片段作为离散事件处理。第二个叙事片段的呈现，以及在较小程度上的混乱片段，追溯性地干扰了第一个片段的记忆。与此同时，后海马对第一部电影的离线反应也减少了。在前海马体中，第二个片段的呈现并没有减少整体离线反应，但显着减少了记忆和遗忘片段之间的活动差异。这些发现与即时离线海马活动反映了事件记录到记忆的主张一致，并表明了回溯干扰的潜在大脑相关性。
In the encoding of narrative episodes, the hippocampus exhibits memory-predictive activity time-locked to stimulus offset. In real life, however, events usually occur in succession, raising the question of how the immediate offline processing of one event is affected by presentation of another. To address this issue, participants were presented with brief narrative movie clips in a functional magnetic resonance imaging scanner. Each clip was immediately followed by an additional, unrelated, clip; by a visually scrambled clip with background auditory noises; or by a fixation cross. Memory for the gist of the clips was tested outside the scanner in a cued-recall test 20 mm after termination of the study session. The hippocampus responded at the offset of each clip, even when a second clip was presented in immediate succession, suggesting that the hippocampus processes each brief clip as a discrete event. Presentation of a second narrative clip, and to a lesser degree of a scrambled clip, retroactively interfered with memory for the first clip. In parallel, the offline response of the posterior hippocampus to the first movie was reduced. In the anterior hippocampus, presentation of a second clip did not reduce the overall offline response but significantly reduced the difference in activity between remembered and forgotten clips. These findings are in line with the proposition that immediate offline hippocampal activity reflects registration of episodes to memory and suggest a potential brain correlate of retroactive interference.