Arbib Michael A
Computer Science Department, Neuroscience Program, and USC Brain Project, University of Southem Califomia, Los Angeles, CA 90089-2520, USA.
Behav Brain Sci. 2005 Apr;28(2):105-24; discussion 125-67. doi: 10.1017/s0140525x05000038.
The article analyzes the neural and functional grounding of language skills as well as their emergence in hominid evolution, hypothesizing stages leading from abilities known to exist in monkeys and apes and presumed to exist in our hominid ancestors right through to modern spoken and signed languages. The starting point is the observation that both premotor area F5 in monkeys and Broca's area in humans contain a "mirror system" active for both execution and observation of manual actions, and that F5 and Broca's area are homologous brain regions. This grounded the mirror system hypothesis of Rizzolatti and Arbib (1998) which offers the mirror system for grasping as a key neural "missing link" between the abilities of our nonhuman ancestors of 20 million years ago and modern human language, with manual gestures rather than a system for vocal communication providing the initial seed for this evolutionary process. The present article, however, goes "beyond the mirror" to offer hypotheses on evolutionary changes within and outside the mirror systems which may have occurred to equip Homo sapiens with a language-ready brain. Crucial to the early stages of this progression is the mirror system for grasping and its extension to permit imitation. Imitation is seen as evolving via a so-called simple system such as that found in chimpanzees (which allows imitation of complex "object-oriented" sequences but only as the result of extensive practice) to a so-called complex system found in humans (which allows rapid imitation even of complex sequences, under appropriate conditions) which supports pantomime. This is hypothesized to have provided the substrate for the development of protosign, a combinatorially open repertoire of manual gestures, which then provides the scaffolding for the emergence of protospeech (which thus owes little to nonhuman vocalizations), with protosign and protospeech then developing in an expanding spiral. It is argued that these stages involve biological evolution of both brain and body. By contrast, it is argued that the progression from protosign and protospeech to languages with full-blown syntax and compositional semantics was a historical phenomenon in the development of Homo sapiens, involving few if any further biological changes.
本文分析了语言技能的神经和功能基础，以及它们在人类进化过程中的出现，假设了从已知存在于猴子和猿类且推测存在于人类祖先的能力，一直到现代口语和手语的发展阶段。起点是观察到猴子的前运动区F5和人类的布洛卡区都包含一个“镜像系统”，该系统在执行和观察手动动作时均活跃，并且F5和布洛卡区是同源脑区。这为里佐拉蒂和阿比比（1998年）的镜像系统假说奠定了基础，该假说将抓握的镜像系统视为2000万年前我们非人类祖先的能力与现代人类语言之间关键的神经“缺失环节”，手动手势而非语音交流系统为这一进化过程提供了最初的种子。然而，本文“超越了镜像”，提出了关于镜像系统内外可能发生的进化变化的假说，这些变化可能使智人具备了语言准备就绪的大脑。这一进程早期阶段的关键是抓握的镜像系统及其扩展以允许模仿。模仿被视为从诸如在黑猩猩中发现的所谓简单系统（允许模仿复杂的“面向对象”序列，但仅作为大量练习的结果）进化到在人类中发现的所谓复杂系统（在适当条件下甚至允许快速模仿复杂序列），后者支持手势表演。据推测，这为原手语的发展提供了基础，原手语是一种组合开放的手动手势库，然后为原语言的出现提供了支架（因此原语言与非人类发声关系不大），原手语和原语言随后以不断扩展的螺旋方式发展。有人认为，这些阶段涉及大脑和身体的生物进化。相比之下，有人认为从原手语和原语言到具有成熟句法和组合语义的语言的发展是智人发展过程中的一个历史现象，几乎没有进一步的生物变化。
