Association for Behavior Analysis International

The significant deficits in expressive language in individuals with Down syndrome begin in infancy, pervade multiple aspects of development, and negatively impact opportunities and outcomes. This symposium will describe research findings from two intervention studies targeting individuals with Down syndrome. The first presentation discusses the use of behavioral interventions targeting babbling in 3-4-month-old infants with Down syndrome, the second presentation discusses teaching vocalizations to children with Down syndrome by addressing mode and function of communication (i.e., vocal and gestural prompts, and social functions). We will highlight how knowledge about the behavioral phenotype for Down syndrome can inform intervention strategies for this population.

Practitioners and Researchers

Individuals with Down syndrome show a distinct behavioral phenotype characterized by relative weakness in expressive language and relative strengths in social interest. Expressive language deficits present in infants with Down syndrome as delays in the onset of babbling, decreased speech sounds, increased non-speech sounds, and poor vocal imitation. Factors that may affect expressive language include fluctuating hearing loss, physiological deficits, and competing behaviors that result in the same consequence. We proposed a behavior analytic model, which explained the early differences in speech sound production in infants with Down syndrome. Using this model, we examined contingent vocal imitation and social consequences as reinforcers to increase the rate of babbling in infants with Down syndrome. Infants showed increases in rate of vocalization during both contingent vocal imitation and social consequences conditions when compared to baseline and a control condition in a reversal design. Findings and collateral changes in related skill areas will be discussed.

Infants with Down syndrome show weaknesses, especially in expressive communication, which, over time, lead to delays in problem solving and a strong tendency to avoid learning opportunities. Strengths in social engagement and motor imitation may be incorporated into interventions. Recent studies teaching manding have drawn on social strengths, but not gestural strengths and motor imitation. Teaching gestural and vocal modes of communication together (total communication) may be particularly beneficial for infants with Down syndrome due to relative strength in motor imitation and gesture use and may even lead to the development of vocalizations. Preliminary results suggest that sign language taught to infants with Down syndrome in a manding intervention with social consequences may facilitate the acquisition of mands with vocalizations and increase the rate of speech sounds. When the total communication mode is combined with a social function, rather than a mand, as the first point of intervention, improvements in vocalizations may be even more robust.