Evolutionary Anthropology Research Group, Department of Anthropology, Durham University, Dawson Building, South Road, Durham DH1 3LE, UK.
Philos Trans R Soc Lond B Biol Sci. 2012 Aug 5;367(1599):2097-107. doi: 10.1098/rstb.2012.0112.
Much attention has focused on the dramatic expansion of the forebrain, particularly the neocortex, as the neural substrate of cognitive evolution. However, though relatively small, the cerebellum contains about four times more neurons than the neocortex. I show that commonly used comparative measures such as neocortex ratio underestimate the contribution of the cerebellum to brain evolution. Once differences in the scaling of connectivity in neocortex and cerebellum are accounted for, a marked and general pattern of correlated evolution of the two structures is apparent. One deviation from this general pattern is a relative expansion of the cerebellum in apes and other extractive foragers. The confluence of these comparative patterns, studies of ape foraging skills and social learning, and recent evidence on the cognitive neuroscience of the cerebellum, suggest an important role for the cerebellum in the evolution of the capacity for planning, execution and understanding of complex behavioural sequences--including tool use and language. There is no clear separation between sensory-motor and cognitive specializations underpinning such skills, undermining the notion of executive control as a distinct process. Instead, I argue that cognitive evolution is most effectively understood as the elaboration of specialized systems for embodied adaptive control.
人们高度关注前脑（尤其是新皮层）的急剧扩张，认为其是认知进化的神经基础。然而，小脑虽然相对较小，但神经元数量却是新皮层的四倍。我发现，常用的比较指标（如新皮层比率）低估了小脑对大脑进化的贡献。一旦考虑到新皮层和小脑连接性的缩放差异，这两个结构明显存在普遍相关进化模式。一个偏离这种普遍模式的例子是，在类人猿和其他采集者中，小脑相对扩张。这些比较模式的融合、对类人猿觅食技能和社会学习的研究，以及最近关于小脑认知神经科学的证据，表明小脑在计划、执行和理解复杂行为序列（包括使用工具和语言）的能力进化中发挥了重要作用。这些技能所依赖的感觉运动和认知专门化之间没有明确的分离，从而破坏了执行控制作为一个独特过程的概念。相反，我认为认知进化最有效地理解为专门化的嵌入式自适应控制系统的发展。
