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…

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…

Cognitive flexibility has been measured with inductive reasoning or explicit rule tasks in individuals with autism spectrum disorders (ASD). The "Flexible Item Selection Task" (FIST) differs from previous cognitive flexibility tasks in ASD research by giving children an abstract, ambiguous rule to switch. The ASD group (N = 22; Mean age = 8.28…

Mathematics is an important aspect of daily life. Basic numeracy skills are needed to accomplish everyday tasks. However, research regarding the relationship between cognitive ability, mental age, and basic numeracy skills for children with intellectual disability (ID) is scarce. This research study investigated the correlation between…

The ability to flexibly adapt to the changing demands of the environment is often reported as a core deficit in fragile X syndrome (FXS). However, the cognitive processes that determine this attentional set-shifting deficit remain elusive. The present study investigated attentional set-shifting ability in fragile X syndrome males with the…

In order to examine the roles of mental age, social interaction, and communication in self-representation abilities, typically-developing children were compared with children with Autism Spectrum Disorders. Typically-developing children (TD, n = 66) and children with Autism Spectrum Disorders (ASD, n = 20), including subgroups of autistic disorder…

We examined recalled narratives of boys with fragile X syndrome with autism spectrum disorder (FXS-ASD; N = 28) and without ASD (FXS-O; N = 29), and compared them to those of boys with Down syndrome (N = 33) and typically developing (TD) boys (N = 39). Narratives were scored for mentions of macrostructural story grammar elements (introduction,…

Studies into the effects of ageing on language in adults with Down syndrome (DS) have tended to rely on measures that lack sensitivity to change because they fail to explore across linguistic domains or rely on proxy reports. The study aim was to use measures of receptive and expressive language from studies of younger individuals with DS in…

Referential communication was studied in children with autism spectrum disorder (ASD) including children with autism and Asperger syndrome. The aim was to study alternative explanations for the children's communicative problems in such situations. Factors studied were theory of mind, IQ, verbal ability and memory. The main results demonstrated…

Background: For pre-school children, the home literacy environment (HLE) plays an important role in the development of language and literacy skills. As there is little known about the HLE of children with intellectual disabilities (ID), the aim of the present study was to investigate the HLE of children with ID in comparison with children without…

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…

It is a matter of debate whether the development of theory of mind (ToM) depends on linguistic development or is, rather, an expression of cognitive development. The study of genetic syndromes, which are characterized by intellectual impairment as well as by different linguistic profiles, may provide useful information with respect to this issue.…

The study found low to moderate correlations between cognitive and play measures for over 200 preschool children classified as mildly retarded, moderately retarded, borderline, and language disordered. Retarded and borderline groups achieved similar mental ages on both measures while language disordered and atypical groups demonstrated marked…

Background: This study describes a new caregiver-report assessment, the Sensory Experiences Questionnaire (SEQ), and explicates the nature of sensory patterns of hyper- and hyporesponsiveness, their prevalence, and developmental correlates in autism relative to comparison groups. Method: Caregivers of 258 children in five diagnostic groups…

To evaluate the claim that correct performance on unexpected transfer false-belief tasks specifically involves mental-state understanding, two experiments were carried out with children with autism, intellectual disabilities, and typical development. In both experiments, children were given a standard unexpected transfer false-belief task and a…