Partner-Specific Adaptation in Disfluency Processing.

Speakers tend to produce disfluencies when naming unexpected or complex items; in turn, when perceiving disfluency, listeners tend to expect upcoming reference to items that are unexpected or complex to name. In two experiments, we examined if these disfluency-based expectations are routine, or instead, if they adapt to the way the speaker uses disfluency in the current context in a talker-specific manner. Participants listened to instructions to look at objects in contexts with several images, some of which lacked conventional names. We manipulated the co-occurrence of disfluency and reference to novel versus familiar objects in a single talker situation (Experiment 1) and in a multi-talker situation (Experiment 2). In the predictive condition, disfluent expressions referred to novel objects, and fluent expressions referred to familiar objects. In the nonpredictive condition, fluent and disfluent trials referred to either familiar or novel objects. Participants' gaze revealed that listeners more readily predicted familiar images for fluent trials and novel images for disfluent trials in the predictive condition than in the nonpredictive condition. In sum, listeners adapted their expectations about upcoming words based on recent experience with disfluency. Disfluency is not invariably processed, but instead a cue that is flexibly interpreted depending on the local context even in a multi-talker setting.