Proceedings of the Annual Meeting of the Cognitive Science Society

Different theories of human syntactic parsing make conflicting claims concerning the role of non-syntactic information (e.g. semantics, real world knowledge) on on-line parsing. W e address this debate by examining the effect of plausibility of thematic role assignments on the processing of syntactic ambiguities. In a selfpaced reading experiment, ambiguous condition reading times were longer than unambiguous condition times at the point of syntactic disambiguation only when plausibility cues had supported the incorrect interpretation. Off-line measures of plausibility also predicted reading time effects in regression analyses. These results indicate that plausibility information m ay influence thematic role assignment and the initial interpretation of a syntactic ambiguity, and they argue against parsing models in which the syntactic component is blind to plausibility information.