High-Risk Siblings without Autism: Insights from a Clinical and Eye-Tracking Study

Joint attention (JA)-the human ability to coordinate our attention with that of other people-is impaired in the early stage of Autism Spectrum Disorder (ASD). However, little is known about the JA skills in the younger siblings of children with ASD who do not develop ASD at 36 months of age [high-risk (HR)-noASD]. In order to advance our understanding of this topic, a prospective multicenter observational study was conducted with three groups of toddlers (age range: 18-33 months): 17 with ASD, 19 with HR-noASD and 16 with typical development (TD). All subjects underwent a comprehensive clinical assessment and an eye-tracking experiment with pre-recorded stimuli in which the visual patterns during two tasks eliciting initiating joint attention (IJA) were measured. Specifically, fixations, transitions and alternating gaze were analyzed. Clinical evaluation revealed that HR-noASD subjects had lower non-verbal cognitive skills than TD children, while similar levels of restricted and repetitive behaviors and better social communication skills were detected in comparison with ASD children. Eye-tracking paradigms indicated that HR-noASD toddlers had visual patterns resembling TD in terms of target-object-to-face gaze alternations, while their looking behaviors were similar to ASD toddlers regarding not-target-object-to-face gaze alternations. This study indicated that high-risk, unaffected siblings displayed a shared profile of IJA-eye-tracking measures with both ASD patients and TD controls, providing new insights into the characterization of social attention in this group of toddlers.

Social orienting and initiated joint attention behaviors in 9 to 12 month old children with autism spectrum disorder: A family home movies study

According to the Social Motivation model children with autism show deficits in social orienting (looking at faces and responding to name) at the end of their first year of life. In this model, those deficits are both the earliest behavioral consequences of an alteration in the dopamine reward system balance and the foundation of the social impairments that characterize this neurodevelopmental disorder. The current study tests two of the main predictions of this model: that social orienting deficits are the first behavioral manifestation of autism, and that they are developmentally related to joint attention deficits. We retrospectively analyzed family home movies of 9- to 12-month-old infants, 29 of whom were later diagnosed with autism and 16 of whom were typically developing. After confirming that the videotapes of both groups were similar in content of the scenes recorded (contexts, type of social activity, etc.), we compared their social orienting (social gaze and responding to name) and joint attention behaviors (gaze alternation and gestures). No significant differences between groups were found in looking at faces, but the group with autism showed deficits in responding to name and initiations of joint attention (IJA). Looking at people was not significantly correlated with IJA behaviors, but response to name was. The lack of group differences in looking at faces between 9 and 12 months, and the existence of IJA difficulties in the ASD group without concurrent impairment in looking at faces, do not support predictions of the Social Motivation model. LAY SUMMARY: Various theories have been proposed to explain the emergence of autism symptoms early in life. This study tested two key predictions of the Social Motivation model. Comparing family movies of children 9- to 12-months-old later diagnosed with autism or with typical development, we did not observe difficulties in looking at other people's faces but children with autism responded to name and used gaze and gestures to direct the adult's attention to events of interest less frequently. This absence of difficulties in looking at faces does not fit with what the Social Motivation model of autism predicts and therefore we must develop alternative explanations.

The Effect of Socioeconomic Disparities on Prefrontal Activation in Initiating Joint Attention: A Functional Near-Infrared Spectroscopy Evidence From Two Socioeconomic Status Groups

Low socioeconomic status (SES) may generally have a long-lasting negative effect on cognitive development, and show deficits in the development of executive functions. However, it is unclear whether there is an SES-dependent disparity in the functional brain development of the prefrontal cortex. By collecting task-related functional near-infrared spectroscopy (fNIRS) data and behavioral data (e.g., intelligence, language, home reading environment (HRE), family income, and parental education level), the current study aimed to detect whether the SES of preschool children (N = 86) is associated with prefrontal activation during the joint attention task. Results verified that low-SES children show lower right prefrontal activation during joint attention than Relatively High-SES children. In addition, our findings confirmed the mediating effect of HRE on the association between SES and brain activation during joint attention, as well as that between SES and language ability. These results suggest that SES contributes to functional development of the prefrontal regions, and the improvement of HRE could be a potential strategy to intervene SES-related disparities on child development.

Contributions of infant vagal regulation at 1 month to subsequent joint attention abilities

Since birth, humans develop an ability to regulate their inner states and behaviors, when facing demanding situations, in order to restore calmness and engage with other persons and the surrounding environment. The present study analyzed whether 1-month infant vagal regulation to auditory stimuli was associated with later joint attention abilities-responding to and initiating joint attention-in interaction with their mothers. Twenty-three infants were assessed and measures of respiratory sinus arrhythmia-RSA (baseline and vagal tone change during auditory stimulation) were used as index of vagal regulation. At 12-months, joint attention behaviors were assessed in a 10-min toy-play mother-infant interaction. Correlational analyses showed that lower baseline RSA and larger increases in vagal tone during auditory stimulation were related to more instances of joint attention behaviors at 12 months, especially responding to joint attention. Results suggest that distinct profiles of autonomic functioning may contribute to joint attention skills.

Joint Attention and Brain Functional Connectivity in Infants and Toddlers

Initiating joint attention (IJA), the behavioral instigation of coordinated focus of 2 people on an object, emerges over the first 2 years of life and supports social-communicative functioning related to the healthy development of aspects of language, empathy, and theory of mind. Deficits in IJA provide strong early indicators for autism spectrum disorder, and therapies targeting joint attention have shown tremendous promise. However, the brain systems underlying IJA in early childhood are poorly understood, due in part to significant methodological challenges in imaging localized brain function that supports social behaviors during the first 2 years of life. Herein, we show that the functional organization of the brain is intimately related to the emergence of IJA using functional connectivity magnetic resonance imaging and dimensional behavioral assessments in a large semilongitudinal cohort of infants and toddlers. In particular, though functional connections spanning the brain are involved in IJA, the strongest brain-behavior associations cluster within connections between a small subset of functional brain networks; namely between the visual network and dorsal attention network and between the visual network and posterior cingulate aspects of the default mode network. These observations mark the earliest known description of how functional brain systems underlie a burgeoning fundamental social behavior, may help improve the design of targeted therapies for neurodevelopmental disorders, and, more generally, elucidate physiological mechanisms essential to healthy social behavior development.

Dopaminergic variants in siblings at high risk for autism: Associations with initiating joint attention

Younger siblings of children with autism spectrum disorder (ASD; high-risk siblings) exhibit lower levels of initiating joint attention (IJA; sharing an object or experience with a social partner through gaze and/or gesture) than low-risk siblings of children without ASD. However, high-risk siblings also exhibit substantial variability in this domain. The neurotransmitter dopamine is linked to brain areas associated with reward, motivation, and attention, and common dopaminergic variants have been associated with attention difficulties. We examined whether these common dopaminergic variants, DRD4 and DRD2, explain variability in IJA in high-risk (n = 55) and low-risk (n = 38) siblings. IJA was assessed in the first year during a semi-structured interaction with an examiner. DRD4 and DRD2 genotypes were coded according to associated dopaminergic functioning to create a gene score, with higher scores indicating more genotypes associated with less efficient dopaminergic functioning. Higher dopamine gene scores (indicative of less efficient dopaminergic functioning) were associated with lower levels of IJA in the first year for high-risk siblings, while the opposite pattern emerged in low-risk siblings. Findings suggest differential susceptibility-IJA was differentially associated with dopaminergic functioning depending on familial ASD risk. Understanding genes linked to ASD-relevant behaviors in high-risk siblings will aid in early identification of children at greatest risk for difficulties in these behavioral domains, facilitating targeted prevention and intervention. Autism Res 2016, 9: 1142-1150. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Joint attention initiation with and without positive affect: risk group differences and associations with ASD symptoms

Infants at risk for autism spectrum disorders (ASD) may have difficulty integrating smiles into initiating joint attention (IJA) bids. A specific IJA pattern, anticipatory smiling, may communicate preexisting positive affect when an infant smiles at an object and then turns the smile toward the social partner. We compared the development of anticipatory smiling at 8, 10, and 12 months in infant siblings of children with ASD (high-risk siblings) and without ASD (low-risk siblings). High-risk siblings produced less anticipatory smiling than low-risk siblings, suggesting early differences in communicating preexisting positive affect. While early anticipatory smiling distinguished the risk groups, IJA not accompanied by smiling best predicted later severity of ASD-related behavioral characteristics among high-risk siblings. High-risk infants appear to show lower levels of motivation to share positive affect with others. However, facility with initiating joint attention in the absence of a clear index of positive affective motivation appears to be central to the prediction of ASD symptoms.