Department of Neurosurgery, Sainte-Anne Hospital, University Paris Descartes, Paris, France.
Neuroimage. 2011 Oct 15;58(4):1131-8. doi: 10.1016/j.neuroimage.2011.06.086. Epub 2011 Jul 7.
Medial temporal lobe (MTL) structures are crucial for episodic memory. However, it remains unclear how these structures are involved in encoding and retrieval processes as a function of recollection and familiarity. To better elucidate MTL organization of these two processes, we implemented an fMRI protocol in which both encoding and retrieval of words were scanned in 21 healthy adults. During encoding, subjects were requested to bind each word to an emotional context (pleasant or unpleasant). Retrieval consisted of a Remember/Know procedure in two stages: first, subjects had to recognize the word, followed by the retrieval of the associated emotional context. fMRI data were reported in eight manually delineated MTL regions of interest (in the head, body and tail of the hippocampus, the entorhinal, perirhinal and parahippocampal cortices, the amygdala and the temporopolar cortex). Results obtained in 19 subjects showed four MTL patterns of activity consisting in activations of parahippocampal cortex and hippocampus in episodic encoding and retrieval and perirhinal cortex involvement in familiarity. These results are in line with the Binding of Item and Context (BIC) model predictions. Additionally, some new findings specified the familiarity MTL neural substrate by showing precise entorhinal activations during retrieval of familiar words, as well as hippocampal and amygdala deactivations in encoding of these words. Finally, we emphasize that among all four memory processes, episodic retrieval (recollection effect) was the only one eliciting strong bilateral activations in all MTL structures. These results should be considered for future studies on MTL dysfunction in patients with temporal lobe damage.
内侧颞叶（MTL）结构对于情景记忆至关重要。然而，这些结构如何作为回忆和熟悉度的函数参与编码和检索过程仍不清楚。为了更好地阐明这两个过程的 MTL 组织，我们在 21 名健康成年人中实施了 fMRI 方案，其中扫描了单词的编码和检索。在编码期间，要求受试者将每个单词与情感语境（愉快或不愉快）相关联。检索由两个阶段的“记住/知道”程序组成：首先，受试者必须识别单词，然后检索相关的情感语境。fMRI 数据报告了八个手动描绘的 MTL 感兴趣区（海马体的头部、身体和尾部、内嗅皮质、旁海马皮质和海马旁回皮质、杏仁核和颞极皮质）。在 19 名受试者中获得的结果显示了四种 MTL 活动模式，包括情景编码和检索中的旁海马皮质和海马体激活以及熟悉度的旁颞叶皮质参与。这些结果与“项目和上下文绑定”（BIC）模型的预测一致。此外，一些新发现通过显示在检索熟悉单词时精确的内嗅皮质激活以及在这些单词的编码中海马体和杏仁核的去激活，进一步说明了熟悉度的 MTL 神经基质。最后，我们强调，在所有四个记忆过程中，情景检索（回忆效应）是唯一在所有 MTL 结构中引起强烈双侧激活的过程。这些结果应在未来研究颞叶损伤患者的 MTL 功能障碍时考虑。
