Overcoming interference: An fMRI investigation of pattern separation in the medial temporal lobe
Overcoming interference: An fMRI investigation of pattern separation in the medial temporal lobe
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DOI：
10.1101/lm.663507
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发表时间：
2007-09-01
影响因子：
2
通讯作者：
Stark, Craig E. L.
中科院分区：
文献类型：
--
作者：
Kirwan, C. Brock;Stark, Craig E. L.
内侧颞叶 (MTL) 支持长期陈述性记忆或事实和日常事件记忆的形成和检索。这种类型的记忆面临的一个挑战源于常见事件的高度重叠。在认知心理学中，人们普遍认为不同时间学到的信息之间的干扰是记忆的主要限制。尽管在干扰理论和陈述性记忆的神经生物学基础领域进行了数十年的深入研究，但很少有直接证据表明 MTL 如何解决这种干扰以形成对日常事实和事件的准确记忆。 MTL 功能的计算模型提出了一种机制，其中 MTL（特别是海马体）执行模式分离，从而使重叠表示变得不太相似。然而，几乎没有证据表明这一过程是如何在完整的人类 MTL 中进行的。使用高分辨率功能磁共振成像，我们进行了一系列实验，通过在修改后的连续识别任务中使用高度相似的干扰刺激来对行为模式分离进行评估。海马旁回内的区域表现出与“回忆拒绝”策略一致的活动。相比之下，海马体内的活动对执行任务至关重要，它区分了正确识别的真实刺激重复、正确拒绝的类似诱饵刺激的呈现以及对类似诱饵的错误警报。这些数据支持计算模型的主张，即海马体在模式分离中起着关键作用。
The medial temporal lobe (MTL) supports the formation and retrieval of long-term declarative memories, or memories for facts and everyday events. One challenge posed for this type of memory stems from the highly overlapping nature of common episodes. Within cognitive psychology, it is widely accepted that interference between information learned at different times is a major limitation on memory. In spite of several decades of intense research in the fields of interference theory and the neurobiological underpinnings of declarative memory, there is little direct evidence bearing on how the MTL resolves this interference to form accurate memories of everyday facts and events. Computational models of MTL function have proposed a mechanism in which the MTL, specifically the hippocampus, performs pattern separation, whereby overlapping representations are made less similar. However, there is little evidence bearing on how this process is carried out in the intact human MTL. Using high-resolution fMRI, we conducted a set of experiments that taxed behavioral pattern separation by using highly similar, interfering stimuli in a modified continuous recognition task. Regions within the parahippocampal gyrus demonstrated activity consistent with a "recall to reject" strategy. In contrast and critical to performing the task, activity within the hippocampus distinguished between correctly identified true stimulus repetitions, correctly rejected presentations of similar lure stimuli, and false alarms to similar lures. These data support the computational models' assertion that the hippocampus plays a key role in pattern separation.