Neural Substrates of Stimulus Recognition and Association Memory

海马体和周围皮质都广泛地与记忆有关；然而，它们对视觉项目识别和位置记忆的相对贡献仍然存在争议。实验性损害内侧颞叶结构的神经心理学研究报告了不同程度的记忆障碍，从轻微的缺陷到严重的健忘症。已发表的研究结果中的差异使得确定海马体和/或周围皮质受损后视觉项目识别和位置记忆障碍的程度变得复杂起来。为了提供到目前为止对总体效应大小的最准确估计，我们使用荟萃分析技术对从26篇文献收集的数据进行分析，这些文献评估了有和没有选择性海马体或周围皮质神经毒性损伤的动物的视觉项目识别和/或位置记忆。我们估计了总体效应大小，评估了病变范围和效应大小之间的关系，并调查了可能解释研究间差异的因素。按病变靶点和检验方法分组研究，进行单独的Meta分析。一项荟萃分析表明，大脑周围皮质损伤后，视觉项目识别测试的损伤比海马体损伤后更大。另一项单独的荟萃分析显示，海马体受损的受试者在位置记忆测试中的表现严重受损。在大多数情况下，元回归表明损伤越大，损伤范围越大；然而，自相矛盾的是，在视觉项目识别测试中，更广泛的海马区损伤预示着更小的损伤。我们得出结论：在视觉项目识别中，海马体对视觉项目识别的贡献大于海马体，而海马体对空间导航的贡献占主导地位。

The hippocampus and perirhinal cortex are both broadly implicated in memory; nevertheless, their relative contributions to visual item recognition and location memory remain disputed. Neuropsychological studies that experimentally damage medial temporal lobe structures report various levels of memory impairment, ranging from minor deficits to profound amnesia. The discrepancies in published findings have complicated efforts to determine the magnitude of visual item recognition and location memory impairments that follow damage to the hippocampus and/or perirhinal cortex. To provide the most accurate estimate to date of the overall effect size, we used meta-analytic techniques on data aggregated from 26 publications that assess visual item recognition and/or location memory in animals with and without selective neurotoxic lesions of the hippocampus or perirhinal cortex. We estimated the overall effect size, evaluated the relation between lesion extent and effect size, and investigated factors that may account for between-study variation. Grouping studies by lesion target and testing method, separate meta-analyses were conducted. One meta-analysis indicated that impairments on tests of visual item recognition were larger after lesions of the perirhinal cortex than after lesions of the hippocampus. A separate meta-analysis showed that performance on tests of location memory was severely impaired in subjects with damage to the hippocampus. For the most part, meta-regressions indicated that greater impairment corresponds with greater lesion extent; paradoxically, however, more extensive hippocampal lesions predicted smaller impairments on tests of visual item recognition. We conclude the perirhinal cortex makes a larger contribution than the hippocampus to visual item recognition, and the hippocampus predominately contributes to spatial navigation.