Psycholinguistic Investigations of Discourse-Based Referential Contrast

Brown University, Providence RI

Investigators

Abstract

A great deal of work in sentence processing over the years has been preoccupied with the question of whether contextual information can influence early parsing decisions. There is by now considerable evidence that suggests that at least some kinds of information from the discourse context do have such effects. However, the question of how these effects occur and where they come from has remained largely ignored. The possible mechanisms for discourse context effects range from very direct ones where classes of linguistic expressions trigger certain discourse representations, to ones involving subtle inferential mechanisms that evaluate the likely discourse functions of alternative linguistic expressions. The studies in this project focus on the discourse properties of modified definite noun phrases. Work in sentence processing has shown that the resolution of ambiguities in which one of the possible readings involves noun modification is affected by the availability of a discourse model in which the modificational phrase serves to distinguish between two possible referents. A central question is whether such discourse effects found with modifiers reflect a general, conventionalized property of modification, or whether they are more aptly characterized as a subtle system of expectations regarding typical usages. A series of studies is proposed to investigate the hypothesis that a typical default expression exists for neutral (i.e. non-contrastive) contexts, and that the use of a more marked or informative expression signals a contrastive function in the discourse that has immediate processing consequences. Data from elicited production tasks will be collected and directly compared with on-line comprehension results from eye movement experiments that allow for the monitoring of subjects' eye movements to a visual array in response to spoken linguistic stimuli. It is suggested here that the discourse effects previously observed with modified NPs are not limited to modified expressions, but extend to other cases involving deviation from a default expression (e.g. the distinction between basic-level and subordinate level expressions as identified in the categorization literature). Experiments testing this hypothesis will be conducted both by means of production and eye monitoring experiments, as well as by building on work in more traditional methodologies such as reading time studies of temporarily ambiguous sentences.