This longitudinal study examined pragmatic language in boys and girls with Down syndrome (DS) at up to three time points, using parent report, standardized and direct assessments. We also explored relationships among theory of mind, executive function, nonverbal mental age, receptive and expressive vocabulary, grammatical complexity, and pragmatic…

The main aims of the current research were to determine when children develop a temporally extended self (TES) and what factors contribute to its development. However, in order to address these aims it was important to, first, assess whether the test of delayed self-recognition (DSR) is a valid measure for the development of the TES, and, second,…

Sensory symptoms are prevalent in autism spectrum disorder but little is known about the early developmental patterns of these symptoms. This study examined the development of sensory symptoms and the relationship between sensory symptoms and adaptive functioning during early childhood. Three groups of children were followed across three time…

Background: Fragile X syndrome (FXS) and Down syndrome (DS) are the two leading genetic causes of intellectual disability, and FXS is the most common known genetic condition associated with autism. Both FXS and DS are associated with significant language impairment, but little is known about expressive language across domains over time or the role…

The present study examined narrative development in children and adolescents with Down syndrome longitudinally. Narratives were collected from 32 children and adolescents with Down syndrome three times over a 1-year period. Both micro- and macrolevel analyses were conducted. Significant growth over the 1-year period was seen in semantic complexity…

Daily living skills (DLS), such as personal hygiene, meal preparation, and money management, are important to independent living. Research suggests that many individuals with autism spectrum disorder exhibit impairments in daily living skills relative to their cognitive skills. This study examined predictors of daily living skills attainment and…

The objective of the current study was to evaluate the patterns of longitudinal change in the language abilities of 28 children with autism during early and middle childhood. Results from fitting a series of multilevel models showed that children's rate of language growth was independently predicted by (a) children's responsiveness to others' bids…

Developmental regression is a complex phenomenon which occurs in 20-49% of the autistic population. Aim of the study was to assess possible differences in the development of regressed and non-regressed autistic preschoolers. We longitudinally studied 40 autistic children (18 regressed, 22 non-regressed) aged 2-6 years. The following developmental…

The English second language development of 19 children (mean age at outset = 5 years, 4 months) from various first language backgrounds was examined every 6 months for 2 years, using spontaneous language sampling, parental questionnaires, and a standardized receptive vocabulary test. Results showed that the children's mean mental age equivalency…