The role of the hippocampus and neocortical areas in the retrieval of past memories in pre‐dementia Alzheimer's disease (AD) patients was investigated. The aim was to assess whether the hippocampus has a temporary role in memory trace formation, according to the Cortical Reallocation Theory (CRT), or whether it continuously updates and enriches memories, according to the Multiple Trace Theory. According to the former theory, hippocampal damage should affect more recent memories, whereas the association cortex is expected to affect memories of the entire lifespan. In the second case, damage to either the hippocampus or the association cortices should affect memories of the entire lifespan. Seventeen patients with amnestic Mild Cognitive Impairment due to AD were submitted to autobiographical (i.e., episodic and semantic personal) memory assessment. Patients underwent MRI for the acquisition of T1‐weighted brain volumes. Voxel‐based morphometry was used to assess correlations between grey matter (GM) volumes and autobiographical memory. Correlation analyses revealed a strict association between GM volumes in the hippocampus and patients’ ability to retrieve the most recent but not the oldest autobiographical memories in both aspects, episodic and semantic. Moreover, patients’ GM volumes in the pre‐frontal and temporal polar areas were associated with recollection of episodic and semantic events, respectively. Finally, GM volumes in the precuneus and occipital cortex were associated with retrieval of the most recent episodic events. These findings indicate that the hippocampus has a specific time‐dependent role; thus, they support the CRT.

中文翻译：

---

海马在阿尔茨海默氏病遗忘型轻度认知障碍患者自传体记忆恢复中的作用。

研究了海马和新皮质区在痴呆前阿尔茨海默氏病（AD）患者过去记忆的恢复中的作用。目的是根据皮质再分配理论（CRT）评估海马是否在记忆痕迹形成中具有暂时性作用，或者根据多重痕迹理论来评估海马是否持续更新和丰富记忆。根据以前的理论，海马损伤应该影响更多的近期记忆，而联想皮层有望影响整个寿命的记忆。在第二种情况下，对海马或相关皮层的损害应影响整个寿命的记忆。将17例因AD引起的轻度轻度认知障碍的遗忘患者接受了自传体检查（即，情景和语义个人）记忆评估。患者接受MRI以获取T1加权脑容量。基于体素的形态计量学用于评估灰质（GM）量与自传体记忆之间的相关性。相关性分析显示，海马中的GM量与患者检索情节和语义两个方面的最新但不是最古老的自传体记忆的能力之间存在严格的关联。此外，患者在额叶前额和颞叶极区的GM量分别与情节事件和语义事件的记忆有关。最后，前额枕和枕叶皮质中的GM量与最近发作的事件有关。这些发现表明，海马具有特定的时间依赖性作用。因此，他们支持CRT。患者接受MRI以获取T1加权脑容量。基于体素的形态计量学用于评估灰质（GM）量与自传体记忆之间的相关性。相关性分析显示，海马中的GM量与患者检索情节和语义两个方面的最新但不是最古老的自传体记忆的能力之间存在严格的关联。此外，患者在额叶前额和颞叶极区的GM量分别与情节事件和语义事件的记忆有关。最后，前额枕和枕叶皮质中的GM量与最近发作的事件有关。这些发现表明，海马具有特定的时间依赖性作用。因此，他们支持CRT。患者接受MRI以获取T1加权脑容量。基于体素的形态计量学用于评估灰质（GM）量与自传体记忆之间的相关性。相关性分析显示，海马中的GM量与患者检索情节和语义两个方面的最新但不是最古老的自传体记忆的能力之间存在严格的关联。此外，患者在额叶前额和颞叶极区的GM量分别与情节事件和语义事件的记忆有关。最后，前额枕和枕叶皮质中的GM量与最近发生的事件有关。这些发现表明，海马具有特定的时间依赖性作用。因此，他们支持CRT。