The gestures produced by children with intellectual disability (ID) in spatial tasks are rarely considered, although they have a supporting role in the formation of thought. In this research study, we analyzed the number of gestures, the type of gestures, and their role in the expression of knowledge of students with ID. Twenty students (12-17…

Communication deficits have a substantial impact on quality of life for individuals with Angelman syndrome (AS) and their families, but limited qualitative work exists to support the necessary content of measures aiming to assess communication for these individuals. Following best practices for concept elicitation studies, we conducted individual…

Young children with developmental disabilities (DD) exhibit a range of strengths and weaknesses in cognitive, language, and adaptive skills. Identifying individual patterns of abilities across these domains is important for informing interventions. This study examines how 129 toddlers with significant developmental delays and less than 10 spoken…

Angelman syndrome (AS) is a neurogenetic disorder characterized by delays including a severe expressive language delay, motor concerns, ataxia, epilepsy, sleep disturbances, gastrointestinal problems, and characteristic behaviors, including a happy demeanor, hyperactivity, and excitability. The syndrome is one of the first neurodevelopmental…

Individuals with a comorbid diagnosis of Down syndrome (DS) and autism spectrum disorder (ASD) have been found to exhibit greater deficits in expressive communication than individuals with DS only. We hypothesized that individuals with a comorbid diagnosis (n = 430) would have significantly lower Communication Matrix scores and specifically social…

The Early Communication Indicator (ECI) was designed to measure expressive communication progress in young children. We evaluated using the 6-min ECI procedure for a new purpose--a sampling context for stable measures of vocal development of young children with autism spectrum disorder (ASD). We evaluated how many ECI sessions were required to…

By adulthood, most males with fragile X syndrome (FXS) require support to navigate day-to-day settings. The present study cross-sectionally: (1) characterized the profile of daily living skills in males with FXS and (2) examined associated participant characteristics (i.e., fragile X mental retardation protein [FMRP] expression, nonverbal…

Despite the importance of expressive language for individuals with autism spectrum disorder (ASD), expressive language assessments are not consistently included in ASD research and many studies do not adequately describe participants' verbal abilities. A valid and efficient measure of expressive language would facilitate consistent reporting…

Changes in minimal verbal communication by children with autism spectrum disorder (ASD) were measured with the Communication Complexity Scale (CCS) and other communication assessments. The CCS measures complexity of preverbal and beginning verbal communication used to communicate behavior regulation and joint attention. The purpose was to…

The development of an expressive language score for people with autism based on the ADOS-2 was recently reported by Mazurek et al. (2019). The current study examined the construct validity of the ADOS-2 expressive language score (ELS) in a sample of adolescents with fragile X syndrome (n = 45, 10 girls), a neurodevelopmental disorder with high…

Forty-two adolescents with Down syndrome (DS) ages 10 to 21 years completed a battery of language and phonological memory measures twice, 2 years apart. Individual differences were highly stable across two years. Receptive vocabulary scores improved, there was no change in receptive or expressive grammar scores, and nonword repetition scores…

The predictive ability of early consonant inventory and intentional communication on later expressive language was examined in 36 boys with fragile X syndrome (FXS). Autism symptom severity was included as a potential moderator. Participants were visited in their homes twice over a 6-year period, and mother-child interactions were videotaped,…

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…

Little is known about the relationships between phonological processing, language, and reading in children with intellectual disability (ID). We examined the structure of phonological processing in 294 school-age children with mild ID and the relationships between its components and expressive and receptive language and reading skills using…

This study tested the hypothesis that pragmatic (i.e., social) language impairment is linked to arousal dysregulation in autism spectrum disorder (ASD) and fragile X syndrome (FXS). Forty boys with ASD, 39 with FXS, and 27 with typical development (TD), aged 4-15 years, participated. Boys with FXS were hyperaroused compared to boys with TD but did…