Purpose: The present study explored the extent to which early prelinguistic communication skills predict expressive language in toddlers with autistic siblings (Sibs-autism), who are known to be at high likelihood for autism and language disorder, and a comparison group of toddlers with non-autistic older siblings (Sibs-NA). Method: Participants…

Identifying infants at elevated likelihood for autism and other developmental differences in the first year of life remains a significant challenge. This study explored associations between behavioral differences in infancy and developmental outcomes in toddlerhood. We conducted a secondary data analysis of 256 infants with an older autistic…

Approximately 3-4 boys for every girl meet the clinical criteria for autism in studies of community diagnostic patterns and studies of autism using samples of convenience. However, girls with autism have been hypothesized to be underdiagnosed, possibly because they may present with differing symptom profiles as compared to boys. This secondary…

Autistic youth often experience challenges in interactions with neurotypical peers. One factor that may influence successful interactions with peers is interpersonal synchrony, or the degree to which interacting individuals align their behaviors (e.g. facial expressions) over time. Autistic and neurotypical youth were paired together into three…

Motor stereotypies are frequently reported in individuals with autism spectrum disorder, but determinants of stereotypies remain poorly understood. In this study, a randomized sample of children with diagnosis of autism spectrum disorder was investigated to identify the prevalence and determinants of stereotypies. A total of 134 children who…

Fragile X syndrome (FXS), the leading heritable cause of intellectual disability, has a co-occurrence rate of autism spectrum disorder (ASD) estimated at ~60%. The onset and rates of motor development in FXS are slower relative to neurotypical development, and even more so in the context of co-occurring FXS + ASD. Extant evidence suggests these…

Purpose: Gesture delay in autistic infants and toddlers has been widely reported. The developmental trajectory of gesture production during early childhood is understudied. Thus, little is known about the possible changes of gesture production over time. The present study aimed to document the development of gesture production in autistic children…

Successful social interactions are assumed to depend on theory of mind--the ability to represent others' mental states--yet most studies of the relation between theory of mind and social-interactive success rely on non-interactive tasks that do not adequately capture the "spontaneous" engagement of theory of mind, a crucial component of…

Purpose: The current study addresses a gap in the literature regarding syntactic development of adolescent boys with fragile X syndrome (FXS) and Down syndrome (DS). Specifically, we ask whether syntactic skills plateau or continue to change during adolescence for these groups and whether the profile of syntactic change differs between boys with…

A recent study suggests that parent report on the Social Symptom and Prosocial scales of the Childhood Joint Attention Rating Scale provides useful information about differences in the social development of school-aged autistic children. The current study provides additional psychometric data on the Childhood Joint Attention Rating Scale regarding…

The use of speech-generating devices (SGD) in early interventions for children with autism spectrum disorder (ASD) can improve communication and spoken language outcomes. The purpose of this study was to describe children's responsiveness to SGD input modeled by a social partner during adult-child play interactions over a 24-week intervention…

Sleep problems are common in autistic children and adversely impact daytime functioning. Knowledge of predictive factors could help with treatment and prevention of these problems. This study aimed to determine predictors of sleep problems among young autistic children. Study cohorts consisted of autistic children aged 2-5 years who did not have…

This study examined factors associated with 9-month outcomes of 78 preschoolers with autism spectrum disorder ([ASD]; 66 males, mean age = 44.8 [7.0] months) receiving preschool special education services. Use of recommended intervention practices was observed in each student's primary educational setting: autism-only (n = 28), mixed-disability (n…

Background & aims: Individuals with non- or minimally verbal autism (nvASD) are primarily characterized by a severe speech production deficit, with speech limited to no or only a few words by school age. Significant unclarity remains over variability in language profiles across the lifespan, the nature of the language impairment seen, and…

This study examined an insufficiently studied predictor of functional language, social motivation, in a group of 87 young children with autism spectrum disorder. Participants (age 14-31 months at the start of the study) were assessed at four times over 24 months. We tested total and indirect associations between early social motivation and later…