Disfluency leads listeners to expect an upcoming reference tounfamiliar objects. In two experiments, we examined if thisexpectation is adapted based on the way disfluency has beenused in the discourse. Participants listened to instructions tolook at an object on a screen containing familiar and novelimages. We manipulated the co-occurrence of disfluency andreference to novel vs. familiar objects. In the predictivecondition, disfluent expressions referred to novel objects, andfluent expressions referred to familiar objects. In the non-predictive condition, fluent and disfluent trials referred toeither familiar or novel objects. Participants’ gaze revealed thatlisteners more readily predicted familiar images for fluent trialsand novel images for disfluent trials in the predictive conditionthan in the non-predictive condition. Listeners adapted theirexpectations about upcoming words based on recentexperience with disfluency. Disfluency is not invariablyprocessed, but is a cue adapted within the local context.

Disfluency in speech leads listeners, even two-year-oldchildren, to expect the speaker to refer to novel and discourse-new objects. Previous evidence suggests this link betweendisfluency and discourse novelty is not driven simply bytracking of co-occurrence statistics connecting disfluency withreference to a new object, but also by integrating extra-linguistic information about the speaker’s perspective. Weasked whether children can attribute a speaker’s disfluency todifferent sources – language planning difficulty vs. distractionfrom the conversation. We tested children’s processing ofdisfluency when interacting with an engaged versus adistracted speaker. When the engaged speaker was disfluent,children looked more at a novel and discourse-new image thanat a familiar and just-named image, consistent with the existingliterature. This disfluency effect was attenuated when thespeaker was distracted, suggesting that four-year-old childrencan flexibly attribute a speaker’s disfluency to different sourcesin online interpretation of disfluent speech.

Modification is often required to differentiate potential referents in discourse context and enhances future memory for those referents. Not yet known is whether the type of modifier produced by younger and older adults differentially affects their object memory. We investigated the use of modifiers and whether it affects memory in younger and older adults. Further, we examined whether the effects vary depending on the type of modifiers produced, namely color versus state. Participants were asked to describe an object that was accompanied by a same-category object of different color or different state, or an unrelated object. A follow-up memory task then assessed their recognition memory. Older adults overspecified more than younger adults. Although modifiers improved memory for both age groups, older adults showed better memory performance. The current finding suggests a link between language production and memory, but we did not observe evidence that specific types of modifiers affected memory.

Social factors, such as partner familiarity (e.g., talking to a friend vs. stranger) may affect some conversations but not others. While researchers do not always control the partner identity when conducting interactive studies, the current empirical report of a language production experiment conducted via Zoom presents effects of partner familiarity (friends vs. strangers) on the form and content of referring expressions in the mundane task of describing everyday objects. First, speakers interacting with a friend were less disfluent than speakers interacting with a stranger, showing that more effort is invested in interactions with strangers. Second, speakers interacting with a friend showed more sensitivity to prior context. Surprisingly, these effects reveal that speakers are sensitive to the partner identity even when describing everyday objects whose labels are shared across all language users. The current findings suggest that researchers should consider social factors as part of the experimental design of interactive tasks.