2018 Sat Poster 6653
Saturday, November 3, 2018 | Poster Session II, Metcalf Small | 3:15pm
Developmental Sequence of Gesture and Expressive Language Milestone Achievement in Toddlers with ASD
M. Talbott, J. Munson, G. Young, A. Estes, S. Rogers
Background: Early speech is one of the strongest predictors of long-term functional outcomes for individuals with autism spectrum disorder (ASD). In typical development, early gestural and linguistic milestones emerge in a reliable sequence: word approximations, followed by first gestures, first words, word and gesture combinations, and two-word speech. Transitions between these milestones are predicted by specific features within each of these stages (Ozçalişkan & Goldin-Meadow, 2005; Rowe & Goldin-meadow, 2009). Toddlers with ASD have impairments in both gesture and early language development, but it is not clear whether these 5 milestones emerge following the typical developmental sequence or whether their transitions are predicted by the same features as typically developing toddlers (Mitchell et al., 2006; Ozçalişkan, Adamson, & Dimitrova, 2015).
Hypotheses: 1) The developmental sequence of early communication skills can be reliably ordered in toddlers with ASD and will follow the same order as typically developing toddlers 2) the onset of single words will be correlated with deictic but not conventional gestures; 3) the onset of two-word combinations will be correlated with the onset of two-word speech but not deictic gestures alone.
Methods: The current sample includes 42 toddlers with ASD participating in a larger parent-mediated treatment study. Toddlers were assessed monthly for 8 months in a play-based format using a 135-item social communication developmental checklist by assessors blind to treatment condition. From this measure, 25 specific items that indexed skills in each of the 5 milestone domains were selected for the present analysis (Table 1).
Results: A Guttman scalogram was constructed by summing the number of children passing each item and items passed per child. Items were sequenced to minimize errors above and below the diagonal. The sequenced scale had a CR = .92, indicating significant reproducibility of the scale. The identified sequence followed expected developmental patterns (see Table 1). There were no significant differences in the number of children who acquired distal points before versus after first words χ2 = 1.938, p = .38. A significantly higher proportion of children acquired gesture-word combinations before two-word phrases, χ2 = 9.750, p = .008. Significant positive correlations were observed between the onset of first words and distal points (rs = .453, p = .034) but not conventional gestures (rs = .334, p =.11). Significant positive correlations were observed between the onset of two-word combinations and gesture-word combinations (rs = .559, p = .03) but not distal points (rs = .051, p = .86) or first words (rs =.487, p = .06).
This study demonstrated that toddlers with ASD follow a typical developmental sequence in the achievement of early gestural and linguistic milestones with the notable exception of distal pointing, which did not reliably emerge before first words as expected. Most toddlers did not acquire two-word speech until they had acquired distal points and started combining single word with gestures. This suggests that intervention to increase early gestures may increase the proportion of children with ASD who acquire multi-word speech and ultimately improve long-term outcomes for individuals with ASD.
References
Mitchell, S., Brian, J., Zwaigenbaum, L., Roberts, W., Szatmari, P., Smith, I., & Bryson, S. (2006). Early language and communication development of infants later diagnosed with autism spectrum disorder. Journal of Developmental and Behavioral Pediatrics, 27, S69–S78.
Ozçalişkan, S., Adamson, L. B., & Dimitrova, N. (2015). Early deictic but not other gestures predict later vocabulary in both typical development and autism. Autism.
Ozçalişkan, S., & Goldin-Meadow, S. (2005). Gesture is at the cutting edge of early language development. Cognition, 96(3), B101-13.
Rowe, M. L., & Goldin-meadow, S. (2009). Differences in Early Gesture Explain SES disparities in child vocabulary size at school entry. Science, 323(13), 951–953.