Resolving Syntactic Category Ambiguities in Discourse Context: Probabilistic and Discourse Constraints

Three experiments investigated the resolution of syntactic category ambiguities in a self-paced reading paradigm, using moving window presentation. Sentences containing noun/verb homographs likeduck(e.g.,She saw her duck and chickens/stumble near the barn.) were embedded in short stories. The first experiment reports the collection of several types of norms to measure the degree to which each homograph was biased toward use as a noun or use as a verb, and the strength of the discourse bias for each item. The goal was to determine how probabilistic lexical bias and discourse bias influence the generation and selection of syntactic structure in the ambiguous region, and this was investigated by varying the length of the ambiguous region in Experiments 2–4. The data suggest that only probabilistic lexical bias influenced the generation of structure, while both lexical bias and discourse bias guided selection of the appropriate structure.