Children's attribution of disfluency to different sources

Disfluency in speech leads listeners, even two-year-old children, to expect the speaker to refer to novel and discourse-new objects. Previous evidence suggests this link between disfluency and discourse novelty is not driven simply by tracking of co-occurrence statistics connecting disfluency with reference to a new object, but also by integrating extralinguistic information about the speaker's perspective. We asked whether children can attribute a speaker's disfluency to different sources - language planning difficulty vs. distraction from the conversation. We tested children's processing of disfluency when interacting with an engaged versus a distracted speaker. When the engaged speaker was disfluent, children looked more at a novel and discourse-new image than at a familiar and just-named image, consistent with the existing literature. This disfluency effect was attenuated when the speaker was distracted, suggesting that four-year-old children can flexibly attribute a speaker's disfluency to different sources in online interpretation of disfluent speech.