Topic situations: Coherence by inclusion

Topic situations have been studied in the linguistic literature but for the most part have not been studied psycholinguistically. Five experiments tested predictions of the hypothesis that a sentence-initial prepositional phrase (PP) in English introduces a Topic Situation, which by default restricts the interpretation of the following discourse. Participants in judgment experiments interpreted later discourse events as being more likely to take place in the location specified by a PP when that PP had appeared sentence-initially compared to other sentence positions, and they rated such sentences as less natural when the discourse event was implausible in the specified location. Participants in two additional experiments made naturalness judgments of sentences containing an initial PP that introduced a situation that has a usual range of durations. Sentences with a final temporal phrase that fell outside this range were judged to be unnatural, suggesting that this temporal phrase was (implausibly) interpreted as being included in the Topic Situation introduced by the PP. We suggest that these findings can advance understanding of discourse phenomena such as presupposition and domain restriction.