Background: Sleep affects children's cognitive development, preparedness for school and future academic outcomes. People with Down syndrome (DS) are particularly at risk for sleep-disordered breathing (SDB). To our knowledge, the association between SDB and cognition in preschoolers with DS is unknown. Methods: We assessed sleep by using…

Background: Research findings on vocabulary development in children with Down syndrome are inconsistent. This study aimed to analyse the developmental trend of vocabulary growth in children with Down syndrome and the relationships between vocabulary and chronological and developmental age. Method: Children's vocabulary size was assessed by a…

The emergence of the Down syndrome (DS) behavioural phenotype during early development may be of great importance for early intervention. The main goal of this study was to investigate the good-imitator-poor-talker developmental profile in DS at preschool age. Twenty children with Down syndrome (DS; mean nonverbal mental age NMA 1 y10 m) and 15…

Children with autism achieve mirror self-recognition appropriate to developmental age, but are nonetheless reported to have problems in other aspects of a sense of self. We observed behaviour in the mirror in 12 pre-school children with autism, 13 pre-school children with Down syndrome (DS) and 13 typically developing (TD) toddlers. Reliable…

Children with Down syndrome (DS) have cognitive disabilities resulting from trisomy 21. Language-learning difficulties, especially expressive language problems, are an important component of the phenotype of this population. Many individuals with DS are born into bilingual environments. To date, however, there is almost no information available…