This chapter highlights a few problems of serial order that may pose problems to a biologically realistic model, problems best explained in the context of theories designed to solve them. Therefore, the following paragraphs sketch examples of linguistic descriptions of syntactic regularities. In addition, technical terms are introduced. Occasionally, a sketch of what a neuron-based approach to syntax might look like may intrude but is developed systematically only in Chapters 9–12.

There are many different approaches to syntaxin theoretical linguistics, and it is not necessary to give an overview of them in the present context. This chapter highlights examples, their choice being primarily motivated by the historical development. So-called phrase structure grammars and their offspring rooted in the work of Harris (1951, 1952) and Chomsky (1957) are in the focus, because the superiorityof phrase structure grammars to a model of serial order in the McCulloch–Pitts (McCulloch & Pitts, 1943) tradition was one of the main reasons in the 1940s and later to base syntax theories on these more abstract algorithms rather than on neuronal algorithms. Apartfrom approaches related to and building on phrase structure grammars, an alternative framework whose roots also date back to the 1940s is mentioned occasionally. This framework, or family of theories, goes back to Tesnière and is called dependency grammar. Clearly, phrase structure grammars anddependency grammars have been modified and much developed, but, as isargued later in this chapter, some of their underlying main ideas persist.