Processing local and unbounded dependencies: A unified account

This paper proposes an account of incremental sentence processing and the initial stage of syntactic ambiguity resolution, based on the claim that the processor seeks to provide semantic interpretations for sentence fragments as soon as it possibly can. In this model, there is no fundamental distinction between local and unbounded dependencies. The processor employs a version of categorial grammar based on dependency grammar, in which dependency constituents are derived from dependencies between words and are permitted to overlap. The processor seeks to form dependency constituents as soon as it can, and to give interpretations to these fragments immediately. The initial stage of ambiguity resolution is determined by theprinciple of dependency formation, under which the processor automatically chooses an analysis that allows a single dependency constituent to be formed in preference to one that does not. The motivation is semantic: Such an analysis maximizes the amount of incremental interpretation that is possible. But if more than one analysis is compatible with the formation of a single constituent, the processor can appeal to a range of sources of nonsyntactic information in making its choice. I show how this account can capture a range of psycholinguistic evidence without positing any fundamental distinction between local and unbounded dependencies.