Competition during the processing of quantifier scope ambiguities: evidence from eye movements during reading

We investigated the processing of sentences containing a quantifier scope ambiguity, such as Kelly showed a photo to each critic, which is ambiguous between the indefinite phrase (a photo) having one or many referents. Ambiguity resolution requires the computation of relative quantifier scope, with either a photo or each critic taking wide scope, thereby determining the number of referents. Using eye tracking, we established that multiple factors, including the grammatical function and surface linear order of quantified phrases, along with their lexical characteristics, interact during the processing of relative quantifier scope, with conflict between factors incurring a processing cost. We discuss the results in terms of theoretical accounts attributing sentence-processing difficulty to either reanalysis (e.g., Fodor, 1982) or competition between rival analyses (e.g., Kurtzman & MacDonald, 1993).