| Natural language utterances are interpreted relative to a body of informational constraints provided by the previous discourse, the perceptual environment, and shared world knowledge. It is common to characterize this contextual information as a type of mental representation or information state which can be formally defined as a set of entities or propositions. Importantly, these contextual representations are not static. As time passes, they are redefined in response to new information and the changing goals of the comprehender. This fact captures the simple truth that words and utterances mean different things on different occasions.; Although an account of contextual "updating" is important for an integrated theory of language comprehension, research on this topic is sparse at best, primarily because of prevailing methodological and theoretical biases toward studying context-invariant aspects of language. Investigations of context effects in on-line comprehension typically focus on the particular point in time at which contextual information is integrated, and neglect the basic processes which make this information available. Existing theoretical models of context updating primarily address the contextual changes produced by the comprehension of an entire sentence, although a more continuous process is likely, and although nonlinguistic information is widely believed to be relevant. Finally, few, if any, empirical investigations of this process have been conducted.; This dissertation explores the mechanisms underlying the real-time construction of the contextual representations which support linguistic reference. A series of five eyetracking experiments investigates the extent of the referential environment considered in the comprehension of definite noun phrases in spoken sentences. The results indicate that referential context is continuously restructured in response to semantic-conceptual constraints derived from the unfolding utterance, pragmatic knowledge of possible actions, and the perceived goals of communication (Experiments 1, 2 and 3). In addition, these rapidly defined domains play an essential role in the on-line resolution of syntactic ambiguities (Experiments 4 and 5). Together, the findings extend existing accounts of incremental interpretation and are consistent with a dynamical view of language processing in which linguistic and nonlinguistic representations coevolve in time to support the recognition of communicative goals. |
