Doré F Y, Thornton J A, White N M, Murray E A
Ecole de Psychologie, Université Laval, Québec, Canada.
Hippocampus. 1998;8(4):323-9. doi: 10.1002/(SICI)1098-1063(1998)8:4<323::AID-HIPO2>3.0.CO;2-I.
Monkeys with removals of medial temporal lobe (MTL) structures are widely recognized as valid models of human global anterograde amnesia, a syndrome that arises consequent to damage to a finite set of brain structures situated in the medial temporal lobe and/or medial diencephalon. However, a comparison of memory deficits in human and nonhuman primates with MTL damage has presented a long-standing puzzle. Whereas amnesic patients are impaired in learning object discrimination problems, monkeys with MTL damage are typically not. One possible explanation for this difference is that object discrimination tasks for humans and monkeys differ in that the former but not the latter requires the use of contextual information. If this analysis is correct, monkeys with MTL damage might be disadvantaged in learning to discriminate similar objects presented in different contexts. To test this possibility, we evaluated the effects of excitotoxic lesions of one of the MTL structures, the hippocampus, on the rate of learning of discrimination problems embedded within unique contexts. Monkeys with hippocampal lesions were impaired relative to controls in learning object discrimination problems of this type. These findings strongly support the idea that the difference in the effect on object memory of MTL damage in human and nonhuman primates is due to a difference in the opportunity to employ contextual cues rather than to a difference in the organization of memory.
内侧颞叶（MTL）结构被切除的猴子被广泛认为是人类整体性顺行性遗忘症的有效模型，这种综合征是由于位于内侧颞叶和/或间脑内侧的一组有限的脑结构受损而产生的。然而，对患有MTL损伤的人类和非人类灵长类动物的记忆缺陷进行比较，一直是一个长期存在的难题。失忆症患者在学习物体辨别问题时存在障碍，而MTL损伤的猴子通常没有。造成这种差异的一个可能解释是，人类和猴子的物体辨别任务有所不同，前者需要使用情境信息，而后者则不需要。如果这个分析是正确的，那么MTL损伤的猴子在学习辨别不同情境中呈现的相似物体时可能会处于劣势。为了验证这种可能性，我们评估了MTL结构之一海马体的兴奋性损伤对嵌入独特情境中的辨别问题学习速度的影响。与对照组相比，海马体损伤的猴子在学习这类物体辨别问题时存在障碍。这些发现有力地支持了这样一种观点，即人类和非人类灵长类动物中MTL损伤对物体记忆的影响差异，是由于利用情境线索的机会不同，而不是记忆组织的差异。
