Proceedings of the Annual Meeting of the Cognitive Science Society

In English, Subject Relative Clauses are processed more quickly than Object Relative Clauses, but open questions remain about where in the clause slowdown occurs. The surprisal theory of incremental processing, under which processing difficulty corresponds to probabilistic expectations about upcoming material, predicts that slowdown should occur immediately on material that disambiguates the subject from object relative clause. However, evidence from eye tracking and self-paced reading studies suggests that slowdown occurs downstream of RC-disambiguating material, on the relative clause verb. These methods, however, suffer from well-known spillover effects which makes their results difficult to interpret. To address these issues, we introduce and deploy a novel variant of the Maze task for reading times (Forster, Guerrera, & Elliot, 2009), called the Interpolated Maze in two English web-based experiments. In Experiment 1, we find that the locus of reading-time differences between SRCs and ORCs falls on immediate disambiguating definite determiner. Experiment 2 provides a control, showing that ORCs are read more slowly than lexically-matching, non-anomalous material. These results provide new evidence for the locus of processing difficulty in relative clauses and support the surprisal theory of incremental processing.