Predicting language outcomes for young prelinguistic children with developmental delay.

The purpose of this study was to examine potential relationships between children's prelinguistic communication behaviors and subsequent (12 months later) expressive and receptive language outcomes. Participants included 25 toddlers with developmental delay and their mothers. The dyads were observed during natural interactions at 6-month intervals over a 12-month period for a total of 3 observation points (O1, O2, O3). Children's rate of nonverbal behavior that is often perceived as communication by adults was identified at O1 and O2. In the investigation, the children's intentional nonverbal communication acts all included coordinated attention between the communication referent and the adult. The other types of prelinguistic communication behavior, termed gestural indicating behavior and social interaction signals, were produced without coordinated attention to the adult. Receptive and expressive language test scores and spontaneous word productions were analyzed at O3 and served as outcome measures in regression analyses. Results indicated that rate of intentional nonverbal communication at O1 was a predictor of spontaneous word productions at O3. At O2, rate of intentional communication and rate of gestural indicating behavior predicted subsequent language outcomes as measured by the Sequenced Inventory of Communication Development-Revised. The results are consistent with previous findings for intentional nonverbal communication that includes coordinated attention, but additionally demonstrate that prelinguistic behavior lacking coordinated attention also bears a relationship to subsequent language outcome. Discussion of observed patterns focuses on child and adult factors that may motivate the transition from prelinguistic to early symbolic communication.