The time course of anticipatory constraint integration

Several studies have demonstrated that as listeners hear sentences describing events in a scene, their eye movements anticipate upcoming linguistic items predicted by the unfolding relationship between scene and sentence. While this may reflect active prediction based on structural or contextual expectations, the influence of local thematic priming between words has not been fully examined. In Experiment 1, we presented verbs (e.g., arrest) in active (Subject-Verb-Object) sentences with displays containing verb-related patients (e.g., crook) and agents (e.g., policeman). We examined patient and agent fixations following the verb, after the agent role had been filled by another entity, but prior to bottom-up specification of the object. Participants were nearly as likely to fixate agents "anticipatorily" as patients, even though the agent role was already filled. However, the patient advantage suggested simultaneous influences of both local priming and active prediction. In Experiment 2, using passive sentences (Object-Verb-Subject), we found stronger, but still graded influences of role prediction when more time elapsed between verb and target, and more syntactic cues were available. We interpret anticipatory fixations as emerging from constraint-based processes that involve both non-predictive thematic priming and active prediction.