Do readers misassign thematic roles? Evidence from a trailing boundary-change paradigm

We report an eye-tracking experiment with a trailing boundary-change paradigm as people read subject- and object-relative clauses that were either plausible or implausible. We sought to determine whether readers sometime misassign thematic roles to arguments in implausible, noncanonical sentences. In some sentences, argument nouns were reversed after participants had read them. Thus, implausible noncanonical sentences like “The bird that the worm ate yesterday was small” changed to plausible “The worm that the bird ate was small.” If initial processing generates veridical representations, all changes should disrupt rereading, irrespective of plausibility or syntactic structure. Misinterpretation effects should only arise in offline comprehension. If misassignment of thematic roles occurs during initial processing, differences should be apparent in first-pass reading times, and rereading should be differentially affected by the direction of the text change. Results provide evidence that readers sometimes misassign roles during initial processing and sometimes fail to revise misassignments during rereading.