Proceedings of the Annual Meeting of the Cognitive Science Society

We describe an experiment to test the view that structural focusing and thematic role focusing are distinct. Subjects were presented >Mth 2-clause sentences containing because or so The first clause introduced two individuals occupying the thematic roles Goal and Source, while the subject of the second was either a pronoun or repeated name. Results showed that reading times for the second clause were facilitated when the pronomis referred to the Goal rather than Source, particularly when the clauses were connected b> so. This facilitation occurred regardless of the surface position of the Goal and regardless of tlie type of anaphor, pronoun or repeated name. With pronouns, facilitation also occurred when the antecedent was in the first position in its clause, but onh when the antecedent was the Source. With Repeated Names, reading times were slowed when the antecedent was in the first position, regardless of its thematic role. These findings suggest that there are two foci in an utterance, one containing the first noun phrase in the utterance and the other containing the preferred thematic role. W e suggest that the focus based on initial mention corresponds to the forward lookmg center described by Grosz et al. (1963) and that the focus based on thematic roles is part of the global focus (Grosz and Sidner, 1986). W e also discuss the implications of our results for Sanford and Garrod's (1981) scenario mapping model.