The early development of infant siblings of children with autism spectrum disorder : characteristics of sibling interactions

Although sibling interactions play an important role in children's early development, they are rarely studied in very young children with an older brother or sister with autism spectrum disorder (ASD). This study used a naturalistic, observational method to compare interactions between 18-month-old infants and their older sibling with ASD (n = 22) with a control group of 18-month-old infants and their typically developing (TD) older sibling (n = 29). In addition, role (a)symmetry and the influence of gender were evaluated. Sibling interactions in ASD-dyads were characterized by higher levels of negativity. Although somewhat less pronounced in ASD-dyads, role asymmetry was present in both groups, with the older child taking the dominant position. Finally, siblings pairs with an older sister were characterized by more positive behaviours. Since differences in sibling interactions may alter the developmental trajectories of both siblings, these early relationships should be taken into account in future ASD research and interventions

Development of neural responses to hearing their own name in infants at low and high risk for autism spectrum disorder

The own name is a salient stimulus, used by others to initiate social interaction. Typically developing infants orient towards the sound of their own name and exhibit enhanced event-related potentials (ERP) at 5 months. The lack of orientation to the own name is considered to be one of the earliest signs of autism spectrum disorder (ASD). In this study, we investigated ERPs to hearing the own name in infants at high and low risk for ASD, at 10 and 14 months. We hypothesized that low-risk infants would exhibit enhanced frontal ERP responses to their own name compared to an unfamiliar name, while high-risk infants were expected to show attenuation or absence of this difference in their ERP responses. In contrast to expectations, we did not find enhanced ERPs to own name in the low-risk group. However, the high-risk group exhibited attenuated frontal positive-going activity to their own name compared to an unfamiliar name and compared to the low-risk group, at the age of 14 months. These results suggest that infants at high risk for ASD start to process their own name differently shortly after one year of age, a period when frontal brain development is happening at a fast rate

Validation of the Language ENvironment Analysis (LENA) system for Dutch

The validity of the Language ENvironment Analysis (LENA) System was evaluatedfor Dutch. 216 5-min samples (six samples per age per child) were selected from daylong recordings at 5, 10 and 14 months of age of native Dutch-speaking younger siblings of children with autism spectrum disorder (N=6) and of typically developing children (N=6). Two native Dutch-speaking coders counted the amount of adult words (AWC),child vocalisations(CVC)and conversational turns (CT). Consequently, correlations between LENA and human estimates were explored. Correlations were high for AWC at all ages (r= .73 to .81). Regarding CVC, estimates weremoderately correlated at 5 months (r= .57) but the correlation decreased at 10 (r= .37) and 14 months (r= .14). Correlations for CT were low at all ages (r= .19 to .28). Lastly, correlations were not influenced by the risk status of the children

Exploring receptive and expressive language components at the age of 36 months in siblings at risk for autism spectrum disorder

Background: Language difficulties are highly prevalent in children with autism spectrum disorder (ASD) as well as in their younger siblings (high-risk (HR) sibs). Children with ASD show substantial heterogeneity in difficulties with different language components, but it remains unknown whether this variability is also present in HR-sibs. Method: Receptive (RL) and expressive language (EL) were evaluated in siblings of typically developing children (low-risk (LR) sibs, N = 33) and HR-sibs (N = 30) at 36 months, using the Mullen Scales of Early Learning (MSEL), the Dutch version of the Reynell Developmental Language Scales - 2nd edition (RDLS-2) and spontaneous language analysis (SL). Next, composite scores for receptive and expressive phonology, grammar, semantics and pragmatics were formed. Group comparisons were performed and delays in the different language components were explored. Results: HR-sibs scored significantly lower than LR-sibs on all standardized measures of RL. For EL, significantly lower scores were only found using the MSEL and not using the RDLS-2 nor using SL. HR-sibs scored significantly lower than LR-sibs for receptive and expressive semantics and receptive grammar. HR-sibs with characteristics of ASD presented with less language difficulties than HR-sibs without characteristics of ASD. The majority of HR-sibs showed a delay in one or more language components but these were not consistently detected by the different measures. Conclusions: Language delays are highly prevalent in HR-sibs and their representation resembles the language profile of children with ASD. Evaluation of language at the level of phonology, grammar, semantics and pragmatics will detect considerably more children experiencing delayed language than holistic approaches

Social interactions between 24-month-old children and their older sibling with autism spectrum disorder : characteristics and association with social-communicative development

This study compared sibling interactions between 24-month-old children and their older sibling with ASD (high-risk; n=24) with 24-month-old children and their typically developing older sibling (low-risk; n=32). First, high-risk sibling pairs showed lower levels of positive behaviour and younger siblings of children with ASD imitated their older sibling less. Second, in the high-risk group positive interactions were positively associated with the youngest child's language abilities. However, this association was no longer significant after controlling for language abilities at 14 months. Third, more total interactions in the high-risk group, both negative and positive, were associated with more ASD characteristics. Thus, early sibling interactions might reveal interesting information in light of the (atypical) developmental trajectories of younger siblings of children with ASD

Atypical development of attentional control associates with later adaptive functioning, autism and ADHD traits

Autism is frequently associated with difficulties with top-down attentional control, which impact on individuals' mental health and quality of life. The developmental processes involved in these attentional difficulties are not well understood. Using a data-driven approach, 2 samples (N = 294 and 412) of infants at elevated and typical likelihood of autism were grouped according to profiles of parent report of attention at 10, 15 and 25 months. In contrast to the normative profile of increases in attentional control scores between infancy and toddlerhood, a minority (7-9%) showed plateauing attentional control scores between 10 and 25 months. Consistent with pre-registered hypotheses, plateaued growth of attentional control was associated with elevated autism and ADHD traits, and lower adaptive functioning at age 3 years