Achieving incremental semantic interpretation through contextual representation.

While much work has been done investigating the role of context in the incremental processing of syntactic indeterminacies, relatively little is known about online semantic interpretation. The experiments in this article made use of the eye-tracking paradigm with spoken language and visual contexts in order to examine how, and when listeners make use of contextually-defined contrast in interpreting simple prenominal adjectives. Experiment 1 focused on intersective adjectives. Experiment 1A provided further evidence that intersective adjectives are processed incrementally. Experiment 1B compared response times to follow instructions such as 'Pick up the blue comb' under conditions where there were two blue objects (e.g. a blue pen and a blue comb), but only one of these objects had a contrasting member in the display. Responses were faster to objects with a contrasting member, establishing that the listeners initially assume a contrastive interpretation for intersective adjectives. Experiments 2 and 3 focused on vague scalar adjectives examining the time course with which listeners establish contrast for scalar adjectives such as tall using information provided by the head noun (e.g. glass) and information provided by the visual context. Use of head-based information was examined by manipulating the typicality of the target object (e.g. whether it was a good or poor example of a tall glass. Use of context-dependent contrast was examined by either having only a single glass in the display (the no contrast condition) or a contrasting object (e.g. a smaller glass). The pattern of results indicated that listeners interpreted the scalar adjective incrementally taking into account context-specific contrast prior to encountering the head. Moreover, the presence of a contrasting object, sharply reduced, and in some conditions completely eliminated, typicality effects. The results suggest a language processing system in which semantic interpretation, as well as syntactic processing, is conducted incrementally, with early integration of contextual information.

Levels of representation in the interpretation of anaphoric reference and instrument inference.

The level of representation accessed when inferences are made during sentence comprehension was examined. The inferences investigated included antecedent assignment for both definite noun phrase anaphors and pronouns and also instrument inferences. In making these inferences, a listener must access the inferred element, whether an antecedent or an instrument, in either a linguistic form representation or a discourse model. The level of representation involved in these inferences was determined by exploiting differences in the lexical decision and naming tasks, which were argued to exhibit differential sensitivity to representational levels. In three experiments, the priming of antecedent and instrument targets in the lexical decision task was compared with priming of the same targets in the naming task. Differences in the patterns of activation across the two tasks indicated that all three types of inferences required accessing elements in a discourse model. Three control experiments ruled out simple context or congruity checking as an explanation for our results. The following conclusions were also supported by these studies: (1) Antecedent assignment occurs immediately after processing an anaphor; (2) antecedent assignment involves inhibition for the inappropriate antecedent rather than facilitation for the appropriate antecedent; (3) although subjects do not make instrument inferences when they hear isolated sentences containing verbs that strongly imply certain instruments, the inferences are made when sentences are preceded by a context that mentions the instrument.

Lexical structure in Parsing long-distance dependencies.

We review a series of experiments investigating lexical influences in parsing sentences with long-distance dependencies. We report three primary results. First, gaps are posited and filled immediately following verbs that are typically used transitively, even when the filler is an implausible object of the verb. However, gaps are not posited after verbs that are typically used intransitively. Second, plausibility determines whether or not a filler is treated as the object of a verb when the verb is typically used with both a direct object and an infinitive complement. Finally, verb control information is used immediately in determining which noun phrase will be interpreted as the "understood" subject of an infinitive complement.