Mesial temporal lobe epilepsy (mTLE) is a neurological disorder associated with histopathological changes in different subfields of the hippocampus. These alterations have been associated with memory difficulties. In this study, we tested the hypothesis that these difficulties stem on mnemonic discrimination impairment due to a reduced ability to make similar representations more distinct, leading to an increased susceptibility to interference. With this aim, we used a visual mnemonic discrimination task and evaluated the ability of a group of patients with unilateral mTLE, relative to controls, to discriminate between a studied item and a new foil item, as a function of the similarity between them, and of the number of exemplars from a category stored in memory. We found that patients performed worse than controls when the studied item had to be discriminated from a physically similar new object from the same basic-level category. Crucially, reliable differences between groups were observable in the conditions in which more exemplars from a category were held in memory. In the conditions in which the studied item had to be discriminated from a foil from a different basic-level category, there were no differences between groups, with one exception. Neither a general cognitive impairment nor a general memory impairment could account for this pattern of results. Current findings indicate that patients found more difficulties in conditions with higher interference, which poses greater demands for pattern separation. A disruption of pattern separation processes resulting from hippocampal damage provides a reasonable interpretation for these results. Future studies should explore the causal relationship between hippocampal subfields integrity and mnemonic discrimination capacity in mTLE patients.

中文翻译：

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单侧中颞叶癫痫患者的记忆识别与记忆中事件的相似性和数量有关。

颞叶颞叶癫痫（mTLE）是一种与海马不同亚区的组织病理学变化相关的神经系统疾病。这些改变与记忆困难有关。在这项研究中，我们检验了以下假设：这些困难归因于助记符歧视受损，原因是使相似表示更加清晰的能力降低，导致对干扰的敏感性增加。为此，我们使用了视觉记忆识别任务，并评估了一组单侧mTLE患者（相对于对照）根据研究对象之间的相似性来区分研究项目和新箔项目的能力，并且内存中存储的类别中示例的数量。我们发现，当必须将研究项目与相同基本级别类别的物理相似新对象区分开时，患者的表现要比对照组差。至关重要的是，在记忆中更多类别样本的情况下，可以观察到各组之间的可靠差异。在必须将研究项目与其他基础级别类别的箔纸区分开的情况下，各组之间没有区别，只有一个例外。一般的认知障碍或一般的记忆障碍都不能解释这种结果模式。当前的发现表明，患者在干扰较大的情况下发现更多的困难，这对图案分离提出了更高的要求。海马损伤导致的模式分离过程中断为这些结果提供了合理的解释。未来的研究应探讨mTLE患者海马亚区完整性与记忆识别能力之间的因果关系。