Klinik für Neurologie, Charité-Universitätsmedizin Berlin, Charitéplatz, Germany.
Hippocampus. 2011 Mar;21(3):309-18. doi: 10.1002/hipo.20752.
Converging evidence from behavioral and imaging studies suggests that within the human medial temporal lobe (MTL) the hippocampal formation may be particularly involved in recognition memory of associative information. However, it is unclear whether the hippocampal formation processes all types of associations or whether there is a specialization for processing of associations involving spatial information. Here, we investigated this issue in six patients with postsurgical lesions of the right MTL affecting the hippocampal formation and in ten healthy controls. Subjects performed a battery of delayed match-to-sample tasks with two delays (900/5,000 ms) and three set sizes. Subjects were requested to remember either single features (colors, locations, shapes, letters) or feature associations (color-location, color-shape, color-letter). In the single-feature conditions, performance of patients did not differ from controls. In the association conditions, a significant delay-dependent deficit in memory of color-location associations was found. This deficit was largely independent of set size. By contrast, performance in the color-shape and color-letter conditions was normal. These findings support the hypothesis that a region within the right MTL, presumably the hippocampal formation, does not equally support all kinds of visual memory but rather has a bias for processing of associations involving spatial information. Recruitment of this region during memory tasks appears to depend both on processing type (associative/nonassociative) and to-be-remembered material (spatial/nonspatial).
来自行为和成像研究的综合证据表明，在人类内侧颞叶（MTL）中，海马结构可能特别参与了联想信息的识别记忆。然而，尚不清楚海马结构是否处理所有类型的联想，或者是否存在专门用于处理涉及空间信息的联想的专业化。在这里，我们在六位接受过右侧 MTL 手术后影响海马结构的患者和十位健康对照者中研究了这个问题。受试者进行了一系列延迟匹配样本任务，有两个延迟（900/5000 毫秒）和三个集大小。要求受试者记住单个特征（颜色、位置、形状、字母）或特征关联（颜色-位置、颜色-形状、颜色-字母）。在单个特征条件下，患者的表现与对照组没有差异。在关联条件下，发现记忆颜色-位置关联的明显依赖于延迟的缺陷。这种缺陷在很大程度上与集大小无关。相比之下，颜色-形状和颜色-字母条件下的表现正常。这些发现支持了这样一种假设，即 MTL 的一个区域，大概是海马结构，并不平等地支持各种视觉记忆，而是对涉及空间信息的联想的处理有偏见。该区域在记忆任务中的招募似乎既取决于处理类型（联想/非联想），也取决于要记住的材料（空间/非空间）。
