The relationship between intonational phrasing and syntactic structure in language production

In this paper, we evaluate several theories of how syntactic/semantic structure influences the placement of intonational boundaries in language production (Cooper & Paccia-Cooper, 1980; Gee & Grosjean, 1983; Ferreira, 1988). Although the theories that we tested are shown to be quite successful, they are complex, and furthermore, they are incompatible with recent evidence for incrementality in sentence production. In light of these problems, we propose a simpler incremental model called the Left hand side/Right hand side Boundary hypothesis (LRB). According to this hypothesis, two factors that underlie the successful performance of the algorithms from the literature contribute to the likelihood of producing intonational boundaries at word boundaries: (1) the size of the recently completed syntactic constituent at a word boundary; and (2) the size of the upcoming syntactic constituent. These factors are further constrained by syntactic argument relationships. We demonstrate that the LRB performs as well as previous models with respect to the data from Experiment 1. In Experiment 2, we present evidence that the LRB outperforms previous models in certain instances. In Experiment 3, we demonstrate that the discourse status of relative clauses is an additional factor in intonational boundary placement.