Processing syntactically ambiguous sentences: evidence from semantic priming

In this paper, we report the results of a study which investigates the processing of syntactically ambiguous sentences. We examined the processing of sentences in which an embedded clause is interpretable as either a complement clause or as a relative clause, as in, for example, "The receptionist informed the doctor that the journalist had phoned about the events." The embedded clause in such sentences is typically analyzed as a complement to the verb informed, rather than as a relative clause modifying the doctor. A number of models parsing predict this is the only analysis ever considered, while others predict that both interpretations are computed in parallel. Using a cross-model semantic priming technique, we probed for activation of doctor just after the embedded verb. Since only the relative clause analysis contains a connection between the doctor and the embedded verb, we expected reactivation of doctor at that point only if the relative clause analysis were a viable option. Our results suggest that this is the case: Compared to priming in an ambiguous control sentence, a significant reactivation effect was obtained. These results are argued to support a model of parsing in which attachment of a clause may be delayed.