Caregiver object labels within supported and coordinated joint engagement during interaction with toddlers at elevated and typical likelihood of autism.

backgroundEarly in development, caregivers' object labelling contributes to children's word learning. Language development is a bi-directional process, and differences in joint engagement (JE) and language among children with developmental disabilities such as autism spectrum disorder (ASD) may provide caregivers varying contexts and opportunities to provide object labels. However, potential variation in caregivers' production of object labels and its relation to language development remain relatively unexplored among toddlers with ASD.

aimsThis study characterized the structural and functional features of object labels produced by parents of children with typical (TL) or elevated likelihood (EL) of ASD during naturalistic toy play. We examined features of object labels within two JE contexts, supported and coordinated JE, which are differentiated by a child's use of eye contact, as well as their relations with concurrent and future child language skills. METHODS & PROCEDURES: The present study included 55 (TL = 12, EL = 43) children who completed a naturalistic parent-child interaction in the home at 18 months of age. Children's expressive and receptive language was assessed at 18, 24 and 36 months. At 36 months, EL children were assessed for ASD and classified as either EL-No Diagnosis, EL-Language Delay or EL-ASD. Videos of interactions were divided into discrete engagement states, including supported and coordinated JE. All parent speech was transcribed and coded to capture structural (types, tokens, mean length of utterance (MLU), sentence position) and functional (follow-in comments, directives, lead-in labels) features of object labels as well as parent prompts for the child to produce a label. OUTCOMES &

resultsParents of toddlers across outcome groups labelled objects at similar rates within each engagement state. However, parents of EL-ASD children provided the lowest rates of prompts for labels in supported JE and the highest rate of labels as the final word of an utterance (sentence-final position) in coordinated JE. Additionally, parent prompts in supported JE were related to concurrent child expressive language. Labels in sentence-final position were positively related to later language outcome when delivered in supported JE but were associated with poorer language outcomes when delivered in coordinated JE. CONCLUSIONS & IMPLICATIONS: Subtle differences in parent object labels across outcome groups demonstrate the role that child language and social engagement can play in influencing parent input and the cascading impact of this input on language development. WHAT THIS PAPER ADDS: What is already known on this subject Variations in caregiver object labelling can impact child language development. However, child characteristics such as language ability also actively shape the input caregivers provide, demonstrating the bi-directionality of language development. What this paper adds to existing knowledge The present study demonstrates that characteristics of the engagement context in which a label is delivered may be important for understanding how object labelling relates to child language acquisition and whether this relation varies for children who face challenges in language learning. What are the potential or actual clinical implications of this work? As child differences in social engagement emerge, parents may be more attuned to moments their children are engaging with eye contact. Caregiver-mediated interventions might consider strategies that guide caregivers in recognizing engagement without eye contact as a similarly meaningful opportunity for learning and encourage the use of rich input within these moments.