Early Joint Attention Predicts Children with Asd's Subsequent Performance on Comprehension Tasks

Background: Joint attention (JA) occurs when two individuals focus on the same object or event. Children’s ability to engage in JA significantly predicts their subsequent language development (Bruinsma et al., 2004; Rollins & Snow, 1998) both in TD children and those with ASD. However, research has only assessed the relationship between early JA and later language production. It is possible that both JA and speech are governed by children’s developing motor abilities (Roos et al., 2008); therefore, it is essential to explore the relationships between JA and later language comprehension. 

Objectives: In this longitudinal study, we compared aspects of children’s JA during parent-child interactions with their later performance on intermodal preferential looking (IPL) tasks assessing word learning and grammatical comprehension. 

Methods: Children were recorded every four months for a total of 6 visits. At the onset of the study, the ASD children (n=17; MA=32.9 months) and TD control children (n=18; MA=20.6 months) were matched on CDI vocabulary production scores (TD mean=118.7 words, ASD mean=94.7 words). Parents and children participated in 30-minute semi-structured play sessions at each visit. Sessions were coded for the number and duration of episodes in which children either responded to or initiated JA. Children also viewed IPL tasks at each visit (e.g., Swensen et al., 2007; Naigles et al., in press) two assessed word learning (NounBias: Do children map novel words onto objects; ShapeBias: Do children extend novel words to objects of the same shape), two assessed grammatical comprehension (WordOrder: Do children understand sentences in SVO order; Aspect: Do children understand that –ing is used for ongoing events and –ed for completed events), and one assessed children’s ability to use transitive frames to learn causative verbs (Syntactic Bootstrapping). Our measure of IPL performance calculated children’s increase in looking at the matching scene during test trials relative to baseline trials. 

Results: Preliminary analyses revealed significant correlations among JA measures within and across visits (rs>.508, ps< .05;ASD: rs>.482, ps< .05). Numerous significant pairwise correlations between JA and IPL comprehension measures were found, therefore, regressions were then performed with children’s Mullen VR, Vineland, CDI production scores entered before the comprehension score (to partial out effects of general cognition, social abilities, and language). TD children who engaged in more or longer JA episodes at visits 1 or 2 performed better on Noun Bias at visit 2 and Wh-Questions at visit 3 (βs ≥.526,  ps<.05). ASD children who engaged in more or longer episodes of JA at visit 1, 2 or 3 performed better on Syntactic Bootstrapping at visit 3,  Shape Bias at visit 4, Wh-Questions at visit 4 and Aspect at visit 5 (βs ≥.511,  ps<.05). 

Conclusions: Stronger JA abilities facilitate the emerging comprehension of several aspects of language; therefore, JA’s influence on language development seems not purely based on shared motor development.  Moreover, JA tends to exert its influence early in language development (Hoff & Naigles, 2002),with ASD children showing effects somewhat later because they are developing more slowly (Fein et al. 1996).