This excursus illustrates circuits motivated by the proposals discussed in Chapter 12. The abbreviations used here and the representation of activity dynamics in table form are the same as those used in Excursuses E2 and E3.

With the extensions of the grammar circuits proposed in Chapter 12, it now becomes possible to treat sentences in which the same word occurs twice and as member of different lexical categories, such as sentence (1).

1. (1) Betty switches the switch on.

In Chapter 10, Figures 10.3 and 10.4 are used to sketch a putative neuronal correlate of the syntactic category representations that may be connected to the representation of the word form switch. Two of the lexical categories, transitive particle verb, here abbreviated as V, and accusative noun, here abbreviated as N, are relevant for the processing of the syntactically ambiguous word used in sentence (1). The homophonous words and their lexical categories are characterized by the assignment formulas (2) and (3) and the valence formulas (4) and (5).

1. (2) switch ↔ V (transitive particle verb)

2. (3) switch ↔ N (accusative noun)

3. (4) V (p /*/ f1, f2, f3)

4. (5) N (p1, p2 /*/)

Figure E4.1 shows the entire network used for sentence processing. The representation of the ambiguous word form is doubled for ease of illustration. This figure is almost identical to Figure E3.1, which dealt with a similar sentence. Table E4.1 presents activity dynamics of the sets involved in processing the ambiguous word and its two lexical categories.