Down Syndrome Research and Practice 10(2)
Using an epidemiological approach to examine outcomes affecting young children with Down syndrome and their families
Hodapp, Urbano, and So
In this paper, we utilise an approach drawn from the field of epidemiology to explore what is known and unknown about young children with Down syndrome and their families. After describing what we mean by an epidemiological approach, we review basic findings for children with intellectual disabilities, as well as challenges to performing such research. In considering the epidemiology of Down syndrome, we note that most studies to date have focused on prevalence, mortality-life expectancy, and rates of diseases and syndrome-related health-physical problems, while neglecting many other important issues. In considering potential advances in the epidemiology of Down syndrome, then, we first overview the process of linking two or more separate administrative records, before reviewing several of our own recent studies. We end this paper by discussing four challenges to future epidemiological studies of children with Down syndrome and their families.
Mahoney, and Perales
In this article we discuss the results of a motor intervention study that we conducted with young children with Down syndrome and other disabilities (Mahoney, Robinson & Fewell, 2001). Results from this study indicated that neither of the two major treatment models that are commonly used with young children with motor impairments was effective at enhancing children's rate of motor development or quality of movement. These findings add to an increasing body of literature indicating that early motor intervention procedures are not adequately meeting the goals envisioned for this endeavour. We argue that there are at least two interrelated reasons why this may be occurring. The first is that parents, who are the people with the greatest opportunities to promote children's motor learning, are not being asked to become active participants in their children's motor intervention. The second is that contemporary models of motor intervention have been focusing on motor learning activities that are incompatible with contemporary theories and research on early motor learning.
Virji-Babul, Kerns, Zhou, Kapur, and Shiffrar
Early intervention approaches for facilitating motor development in infants and children with Down syndrome have traditionally emphasised the acquisition of motor milestones. As increasing evidence suggests that motor milestones have limited predictive power for long-term motor outcomes, researchers have shifted their focus to understanding the underlying perceptual-motor competencies that influence motor behaviour in Down syndrome. This paper outlines a series of studies designed to evaluate the nature and extent of perceptual-motor impairments present in children with Down syndrome. 12 children with Down syndrome between the ages of 8-15 years with adaptive ages between 3-7 years (mean age = 5.6 years +/- 1.45 years) and a group of 12 typically developing children between the ages of 4-8 years (mean age = 5.4 +/- 1.31 years) were tested on their ability to make increasingly complex perceptual discriminations of motor behaviours. The results indicate that children with Down syndrome are able to make basic perceptual discriminations but show impairments in the perception of complex visual motion cues. The implications of these results for early intervention are discussed.
Language learning in Down syndrome: The speech and language profile compared to adolescents with cognitive impairment of unknown origin
Children and adolescents with Down syndrome show an emerging profile of speech and language characteristics that is typical of the syndrome (Chapman & Hesketh, 2000; Chapman, 2003; Abbeduto & Chapman, 2005) and different from typically developing children matched for nonverbal mental age, including expressive language deficits relative to comprehension that are most severe for syntax, and, in adolescence, strengths in comprehension vocabulary, improvements in expressive syntax, but losses in comprehension of syntax (Chapman, Hesketh & Kistler, 2002). Here we compare 20 adolescents with Down syndrome to16 individuals with cognitive impairment of unknown origin, statistically matched for age and nonverbal mental age, to show that the age-related strengths in vocabulary comprehension are not limited to the Down syndrome phenotype, but are limited to a certain type of vocabulary test: for both groups, performance on the Peabody Picture Vocabulary Test-3 is significantly greater than performance on the vocabulary subtest of the Test of Auditory Comprehension of Language-3, which does not differ from the syntax comprehension subtests. Vocabulary size, but not conceptual level, is a strength for adolescents with cognitive impairment. In contrast, deficits in auditory-verbal working memory, syntax and vocabulary comprehension, and narration of picture-books without an opportunity to preview them are all specific to the adolescent group with Down syndrome. The expressive language deficit disappears when a preview opportunity and picture support is given.
For decades, researchers and practitioners have attempted to find evidence for a personality stereotype in individuals with Down syndrome that includes a pleasant, affectionate, and passive behaviour style. However, a more nuanced exploration of personality-motivation in Down syndrome reveals complexity beyond this pleasant stereotype, including reports of a less persistent motivational orientation and an over-reliance on social behaviours during cognitively-challenging tasks. It is hypothesised that the personality-motivation profile observed in individuals with Down syndrome emerges as a result of the cross-domain relations between more primary (cognitive, social-emotional) aspects of the Down syndrome behavioural phenotype. Young children with Down syndrome show a general profile of delays in the development of instrumental thinking coupled with emerging relative strengths in social-emotional functioning. If it is true that a less persistent motivational orientation emerges as a secondary phenotypic result of more primary strengths in social functioning and deficits in instrumental (means-end) thinking, it may be possible to alter the developmental trajectory of this personality-motivation profile with targeted and time-sensitive intervention. Implications for intervention planning are discussed.