Children’s Use of Disfluencies for Pragmatic Inference in Lexical Development

In early lexical development, children must learn to map spoken words onto their respective referents. Since multiple objects are typically present when any word is used, a child is charged with the difficult task of inferring the speaker’s intended referent. Previous research has uncovered various cues children may use in this task, including contextual and social cues. We investigate a previously unexplored cue for inferring speaker intention during word learning: speech disfluencies. Disfluencies (such as “uh” and “um”) occur in highly predictable locations, such as before words that are infrequent and words that have not been previously mentioned. Further, since they occur before such words, they could enable a young word learner to anticipate an upcoming referent. We conducted an eye-tracking study to investigate whether young children can make use of the information contained in disfluencies. Our results demonstrate that young children (ages 2;4 to 2;8) are sensitive to disfluencies. More critically, they show that children appear to use disfluencies predictively as a cue to reference and to speaker intention as the disfluency is occurring. We also examined potential sources of learning about disfluencies in CHILDES (MacWhinney, 2000) and found that disfluencies, though rare, occur regularly and with increasing frequency over time in childdirected and child-produced speech. These results demonstrate that a feature of the speech signal that likely emerges as a by-product of processing demands in adults is attended to relatively early in lexical development and used by young children to infer speaker intention during online comprehension.