Toward optimal outcome following pivotal response treatment: a case series

Objective: The objectives of this review are to highlight the impact of the first decade of high-risk (HR) infant sibling work in autism spectrum disorder (ASD) and to identify potential areas of translational focus for the next decade of research.

Method: A group of clinicians and researchers in ASD working both inside and outside of the HR design met on a regular basis to review the infant sibling research, and came to an agreement on areas that had changed clinical practice and areas that had the potential to change practice with further research. The group then outlined several methodological and translational challenges that must be addressed in the next decade of research if the field is to reach its potential.

Results: The review concluded that the HR design has yielded an understanding that ASD often, but not always, begins to emerge between 6 and 18 months, with early signs affecting social communication. Research using the HR design has also allowed a better understanding of the sibling recurrence risk (between 10% and 20%). Emerging areas of interest include the developmental trajectories of social communications skills in the early years, the expression of a milder phenotype in siblings not affected with ASD, and the possibility that early intervention with infant siblings may improve outcomes for those with ASD. Important challenges for the future include linking screening to intervention, collecting large sample sizes while ensuring cross-site reliability, and building in capacity for replication.

Conclusion: Although there are significant methodological and translational challenges for high-risk infant sibling research, the potential of this design to improve long-term outcomes of all children with ASD is substantial.

Keywords: autism; development; longitudinal; opportunities; sibling.

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects more than 1 % of the population and close to 20 % of prospectively studied infants with an older sibling with ASD. Although significant progress has been made in characterizing the emergence of behavioral symptoms of ASD, far less is known about the underlying disruptions to early learning. Recent models suggest that core aspects of the causal path to ASD may only be apparent in early infancy. Here, we investigated social attention in 6- and 12-month-old infants who did and did not meet criteria for ASD at 24 months using both cognitive and electrophysiological methods. We hypothesized that a reduction in attention engagement to faces would be associated with later ASD.

Methods: In a prospective longitudinal design, we used measures of both visual attention (habituation) and brain function (event-related potentials to faces and objects) at 6 and 12 months and investigated the relationship to ASD outcome at 24 months.

Results: High-risk infants who met criteria for ASD at 24 months showed shorter epochs of visual attention, faster but less prolonged neural activation to faces, and delayed sensitization responses (increases in looking) to faces at 6 months; these differences were less apparent at 12 months. These findings are consistent with disrupted engagement of sustained attention to social stimuli.

Conclusions: These findings suggest that there may be fundamental early disruptions to attention engagement that may have cascading consequences for later social functioning.

Keywords: ASD; Event-related potential; Habituation; Social attention; Social information processing.