Skeen L C, Masterton R B
Brain Behav Evol. 1976;13(2-3):179-95. doi: 10.1159/000123809.
A species of prosimian (bush baby, Galago senegalensis) was tested on delayed-alternation and spatial-reversal learning before and after ablation of prefrontal cortex. The results show that normal performance on the two behavioral tasks depend on different subdivisions of the MD-prefrontal system. Delayed alternation is disrupted by prefrontal lesions which cause degeneration in the lateral division of MD while spatial-reversal learning is disrupted by lesions causing degeneration of the medial division of MD. Therefore, the bush baby prefrontal system can be subdivided either on behavioral or anatomical grounds into at least two chief parts. Because of several similarities in the MD-prefrontal system of bush baby and monkey despite their remote common ancestry, it can be concluded that the differentiation of the MD-prefrontal system into distinct divisions and the involvement of this system in delayed alternation and spatial reversal are features probably as old as the order Primates itself. It can be further concluded that the further evolution of the anthropoid variety of prefrontal system beyond this common primate stage probably depended on selective pressure on abilities other than those measured here.
一种原猴亚目动物（丛猴，塞内加尔婴猴）在额叶前部皮质切除前后接受了延迟交替和空间反转学习测试。结果表明，这两项行为任务的正常表现取决于丘脑背内侧核 - 额叶前部系统的不同细分区域。延迟交替行为会因额叶前部损伤而受到干扰，这种损伤会导致丘脑背内侧核外侧部退化，而空间反转学习则会因导致丘脑背内侧核内侧部退化的损伤而受到干扰。因此，丛猴的额叶前部系统在行为或解剖学基础上至少可细分为两个主要部分。尽管丛猴和猴子在进化上的亲缘关系较远，但它们的丘脑背内侧核 - 额叶前部系统存在一些相似之处，由此可以得出结论，丘脑背内侧核 - 额叶前部系统分化为不同区域以及该系统参与延迟交替和空间反转行为，这些特征可能与灵长目本身一样古老。还可以进一步得出结论，类人猿额叶前部系统在这一共同的灵长类阶段之后的进一步进化，可能取决于除了此处所测量的能力之外的其他能力所受到的选择压力。
