The most common type of overt interruption of fluent speech, or disfluency, is the filled pause is in which filler interrupts production of an utterance. Speakers produce filled pauses for a variety of reasons, such as to discourage interruptions or to gain additional time to plan utterances. It reports a visual world experiment in which participant's eye movements were monitored while they responded to ambiguous utterances containing filled pauses by manipulating objects placed in front of them. Two particular patterns of eye movements have been used to draw inferences about comprehension: anticipatory and confirmatory eye movements. Participant's eye movements and actions suggested that filled pauses informed resolution of the current referential ambiguity, but did not affect the final parse. The chapter presents an experiment that directly tests whether a cueing mechanism can modulate the interpretation of a fully ambiguous utterance in the presence of a fully ambiguous visual world. The results suggest that filled pauses provide a unique window on sentence processing in general, because they show what ambiguities are relevant at that point in the utterance. © 2007 Elsevier Ltd.