UCLA

In some discourses, a given inference would be natural at one point, but impossible at the next. We focus here on such cases with inferences of temporal and causal order usually described as ambiguities of discourse coherence. The fact that these inferences come and go over the course of a discourse raises challenges for their representation within theories of dynamic semantics: representations must either include coherence-related meaning in a way that can be selectively edited later, or else persistently underspecify it. As theories of humans' actual cognitive states, these approaches make different predictions for patterns of difficulty during real-time comprehension. Borrowing a standard assumption from sentence processing, true incremental representation should be associated with some detectable "Regret" when a comprehender meets input incompatible with a previously-preferred analysis. Previous work on the processing of coherence has failed to demonstrate Regret, leaving underspecification on the table. In a new study, we probe further, by constructing discourses with a strong, verified bias towards an initial inference, and testing the effects of cues which can reverse this inference early in the discourse, or much later. We observe that these discourses provoke Regret in self-paced reading, in particular when the critical cue comes late, in a discourse unit following the initial ambiguity. Among many formal accounts which could explain this pattern, we elaborate in particular on a version of Segmented Discourse Representation Theory where analyses are ranked at the offset of each discourse unit.