Active dependency formation and ambiguity resolution in real-time sentence processing.

In late-closure garden-path sentences such as "Whenever the boys hug Tom smiles happily", the locally ambiguous noun phrase ("Tom") is initially analysed as the direct object of the embedded verb ("hug") and is later revised as the subject of the matrix clause once the disambiguating verb ("smiles") is encountered. The present study investigated whether active dependency formation affects the resolution of this ambiguity in three self-paced reading experiments. The experimental sentences contained wh-trace and/or PRO-controller dependencies, which were designed to introduce biases towards the subject analysis. The results showed that, although active dependency formation did not prevent the object analysis, it did reduce the revision cost at the disambiguating verb. This reduction was more pronounced when multiple unresolved dependencies were present than when only a single unresolved dependency was present. We discuss the implications of these findings for our understanding of how dependencies are established and how ambiguities are resolved during real-time sentence processing.