Levy D A, Bayley P J, Squire L R
Veterans Affairs Healthcare System, San Diego, CA 92161, USA.
Proc Natl Acad Sci U S A. 2004 Apr 27;101(17):6710-5. doi: 10.1073/pnas.0401679101. Epub 2004 Apr 16.
Semantic knowledge (e.g., long-established knowledge about objects, facts, and word meanings) is known to be severely impaired by damage to the anterolateral temporal lobe. For example, patients with semantic dementia have prominent atrophy in anterolateral temporal cortex and also have significant damage within the medial aspect of the temporal lobe. However, there is uncertainty about the contribution of medial temporal lobe damage, including perirhinal cortex damage, to impaired semantic knowledge. Drawing largely on published material from multiple sources, we compared the performance of severely amnesic patients with large medial temporal lobe lesions and patients with semantic dementia on nine tests of semantic knowledge and two tests of new learning ability. On the tests of semantic knowledge, the amnesic patients performed markedly better than the patients with semantic dementia. By contrast, on the tests of new learning, the patients with semantic dementia performed markedly better than the amnesic patients. We conclude that medial temporal lobe damage impairs the formation of declarative memory, and that semantic knowledge is impaired to the extent that damage extends laterally in the temporal lobe. Reports that the extent of atrophy in perirhinal cortex correlated with the severity of impaired semantic knowledge may be understood by supposing that the extent of damage in many temporal lobe areas is intercorrelated in this progressive disease, and that the extent of atrophy in perirhinal cortex is a proxy for the overall severity of dementia.
语义知识（例如，关于物体、事实和词义的长期知识）已知会因前外侧颞叶受损而严重受损。例如，语义性痴呆患者的前外侧颞叶皮质有明显萎缩，并且颞叶内侧也有显著损伤。然而，包括鼻周皮质损伤在内的内侧颞叶损伤对语义知识受损的影响尚不确定。我们主要借鉴多个来源的已发表材料，比较了内侧颞叶有大面积损伤的严重失忆患者和语义性痴呆患者在九项语义知识测试和两项新学习能力测试中的表现。在语义知识测试中，失忆患者的表现明显优于语义性痴呆患者。相比之下，在新学习测试中，语义性痴呆患者的表现明显优于失忆患者。我们得出结论，内侧颞叶损伤会损害陈述性记忆的形成，并且语义知识受损的程度与颞叶外侧损伤的范围有关。关于鼻周皮质萎缩程度与语义知识受损严重程度相关的报道，可以通过假设在这种进行性疾病中许多颞叶区域的损伤程度相互关联，且鼻周皮质萎缩程度是痴呆总体严重程度的一个指标来理解。
