Naess, K. (2016). Development of phonological awareness in Down syndrome: A meta-analysis and empirical study. Developmental Psychology, 52(2), 177.
Phonological awareness (PA) is the knowledge and understanding of the sound structure of language and is believed to be an important skill for the development of reading. This study explored PA skills in children with Down syndrome and matched typically developing (TD) controls using a dual approach: a meta-analysis of the existing international literature and a longitudinal empirical study. The results from both the meta-analysis and the empirical study showed that the children with Down syndrome initially had weaker PA skills compared to the controls; in particular, the awareness of rhyme was delayed. The longitudinal empirical data indicated that, as a result of formal education, the children with Down syndrome exhibited greater improvement on all PA measures compared with the controls who had not yet entered school. The results reach significance for rhyme awareness. With respect to dimensionality, the performance of the children with Down syndrome loaded on 1 factor, whereas the performance of the younger TD controls was multidimensional. In sum, these findings underline the need for studies that compare interventions designed especially to stimulate development of PA in this group of children and to provide insight into the underlying causes of the developmental profile of children with Down syndrome.
Næss, Lervåg, Lyster, & Hulme. (2015). Longitudinal relationships between language and verbal short-term memory skills in children with Down syndrome. Journal of Experimental Child Psychology, 135, 43-55.
Longitudinal Relationships between Language and Verbal Short-term Memory Skills in Children with Down Syndrome Abstract Children with Down syndrome are at risk of language difficulties; the nature of which are not well understood. This study compares the longitudinal predictors of language skills in children with Down syndrome with that of typically developing control children matched for initial level of non-verbal mental ability. An age-cohort of children with Down syndrome (N = 43) and 57 typically developing control children were assessed on measures of vocabulary, grammar and verbal short-term memory 3 times at yearly intervals. Children with Down syndrome showed slower development on all measures than the typically developing controls. Longitudinal analyses showed moderate to high stability of language and verbal short-term memory skills. Our results confirm earlier evidence of pervasive language learning difficulties in this group and suggest that early language intervention should be given high priority.
Naess, K.-A. B., et al. (2012). "Reading Skills in Children with Down Syndrome: A Meta-Analytic Review." Research in Developmental Disabilities: A Multidisciplinary Journal (2): 737-747.
The authors examine the reading profile in children with Down syndrome by comparing the nonword decoding skills in children with Down syndrome and typically developing children matched for word recognition level. Journal articles published before 04.05.2010 were identified by using the keyword Down* cross-referenced to "reading", "literacy", "decoding", and "reading comprehension" were selected. A total of eight papers met the criteria for inclusion. Each study was reviewed and coded on both inclusion criteria and coding protocol before the analysis was performed. Children with Down syndrome had equivalent nonword decoding skills to typically developing children matched for word recognition level, but showed deficits on measures of two important underlying skills, vocabulary and phonological awareness. Differences in vocabulary, but not phonological awareness, were predictive of differences in nonword decoding skills. The practical and theoretical implications of these findings are discussed. (Contains 3 figures and 1 table.)
Naess, K.-A. B., et al. (2011). "Language and Verbal Short-Term Memory Skills in Children with Down Syndrome: A Meta-Analytic Review." Research in Developmental Disabilities: A Multidisciplinary Journal (6): 2225-2234.
This study presents a meta-analytic review of language and verbal short-term memory skills in children with Down syndrome. The study examines the profile of strengths and weaknesses in children with Down syndrome compared to typically developing children matched for nonverbal mental age. The findings show that children with Down syndrome have broad language deficits (that are not restricted to measures of expressive language) and associated verbal short-term memory deficits. The profile of language skills in children with Down syndrome shows similarities to that seen in children with Specific Language Impairment. The practical and theoretical implications of these findings are discussed. (Contains 1 table and 5 figures.)