Bellman K L, Goldberg L J
Am J Physiol. 1984 Jun;246(6 Pt 2):R915-21. doi: 10.1152/ajpregu.1984.246.6.R915.
We start with the view that the development of systems of symbols is rooted in the regulation of cellular processes and the behavior of unicellular animals. Animals would thereafter start to externalize these internal symbol systems, to coordinate movements with each other. We propose that the brains of multicellular animals can be understood as a continuing elaboration of the early chemical symbol systems of unicellular animals: the labile symbols of the unicellular animal are replaced by hormones, more stable chemical compounds, and nerves that are seen as more stable and more specific routes of activation; and brains developed layers of symbols such that the domain of a symbol is not a set of bodily processes but rather a set of brain processes. Human language is very much in the "style" of the rule-governed symbol manipulation required by all behaving animals, although unique in its complexity. We suggest that the essential question is not how humans have evolved symbolic and linguistic abilities from a primitive sensorimotor brain but rather how do symbols come to exist in biological systems and what is useful and necessary about a system of symbols for the coordination of action within animals and among animals.
我们首先认为，符号系统的发展植根于细胞过程的调节和单细胞动物的行为。此后，动物开始将这些内部符号系统外化，以便相互协调行动。我们提出，多细胞动物的大脑可以被理解为单细胞动物早期化学符号系统的持续细化：单细胞动物不稳定的符号被激素、更稳定的化合物以及被视为更稳定、更特定激活途径的神经所取代；大脑发展出了多层符号，使得符号的领域不是一组身体过程，而是一组大脑过程。人类语言非常符合所有行为动物所需的规则支配的符号操纵“风格”，尽管其复杂性独一无二。我们认为，关键问题不是人类如何从原始的感觉运动大脑进化出符号和语言能力，而是符号如何在生物系统中存在，以及符号系统对于动物内部和动物之间的行动协调有哪些有用和必要之处。
