2012Kennedy Krieger InstituteKlaus LibertusRebecca Landa
Effects of Active Motor & Social Training on Developmental Trajectories in Infants at High Risk for ASD
Although social impairments are considered the hallmark deficit of autism, many behavioral intervention studies rely on cognitive functioning as a primary outcome. Fewer studies have examined whether changes in cognition are associated with changes in social functioning. This study examined whether cognitive gains among 192 students from 47 kindergarten-through-second-grade autism support classrooms participating in a year-long behavioral intervention study were associated with gains in social functioning. Children’s gains in cognitive ability were modestly associated with independent assessors’ and teachers’ evaluations of social functioning but were not associated with changes in parent ratings. Observed social gains were not commensurate with gains in cognition, suggesting the need both for interventions that directly target social functioning and relevant field measures of social functioning.
Keywords: autism spectrum disorder; intervention; social deficits.
Empirical studies have documented a variety of social abnormalities in infancy that indicate risk for later social and behavioral difficulties. There is very little research illustrating the presence of such behavioral vulnerabilities with frequent repeated measures, and the feasibility of designing interventions for improving social engagement in infants under one year of age. In the context of a multiple baseline research design, three young infants, ages 4, 7, and 9 months referred for concerns about social engagement were assessed for affect, social interest, eye contact avoidance, and response to name. Additionally, the feasibility of implementing an intervention to target social behaviors was examined. Results demonstrated that: (1) consistently low or erratic levels of social behavior were evident throughout the baseline assessment period; (2) these patterns could be improved with a brief intervention (a modified Pivotal Response Treatment) showing an immediate increase and stability of social engagement; and (3) social engagement remained at a stable and high level at follow-up. The results are discussed in terms of implications of early assessment and intervention for clinical populations, including infants with Autism Spectrum Disorder.
Keywords: autism spectrum disorder; early intervention; infants; social intervention.
Pivotal Response Treatment (PRT) is an empirically validated behavioral treatment for individuals with autism spectrum disorders (ASD). The purpose of the current study was to assess the efficacy of PRT for ten cognitively-able preschool-aged children with ASD in the context of a short-duration (4-month) treatment model. Most research on PRT used individual behavioral goals as outcome measures, but the current study utilized standardized assessments of broader-based social communication and adaptive skills. The children made substantial gains; however, magnitude and consistency of response across measures were variable. The results provide additional support for the efficacy of PRT as well as evidence for improvements in higher-order social communication and adaptive skill development within the context of a short-duration PRT model.
We investigated the mechanisms by which Pivotal Response Treatment (PRT) improves social communication in a case series of 10 preschool-aged children with Autism Spectrum Disorder (ASD). Functional magnetic resonance imaging (fMRI) identified brain responses during a biological motion perception task conducted prior to and following 16 weeks of PRT treatment. Overall, the neural systems supporting social perception in these 10 children were malleable through implementation of PRT; following treatment, neural responses were more similar to those of typically developing children (TD). However, at baseline, half of the children exhibited hypoactivation, relative to a group of TD children, in the right posterior superior temporal sulcus (pSTS), and half exhibited hyperactivation in this region. Strikingly, the groups exhibited differential neural responses to treatment: The five children who exhibited hypoactivation at baseline evidenced increased activation in components of the reward system including the ventral striatum and putamen. The five children who exhibited hyperactivation at baseline evidenced decreased activation in subcortical regions critical for regulating the flow of stimulation and conveying signals of salience to the cortex-the thalamus, amygdala, and hippocampus. Our results support further investigation into the differential effects of particular treatment strategies relative to specific neural targets. Identification of treatment strategies that address the patterns of neural vulnerability unique to each patient is consistent with the priority of creating individually tailored interventions customized to the behavioral and neural characteristics of a given person.
Earlier autism diagnosis, the importance of early intervention, and development of specific interventions for young children have contributed to the emergence of similar, empirically supported, autism interventions that represent the merging of applied behavioral and developmental sciences. “Naturalistic Developmental Behavioral Interventions (NDBI)” are implemented in natural settings, involve shared control between child and therapist, utilize natural contingencies, and use a variety of behavioral strategies to teach developmentally appropriate and prerequisite skills. We describe the development of NDBIs, their theoretical bases, empirical support, requisite characteristics, common features, and suggest future research needs. We wish to bring parsimony to a field that includes interventions with different names but common features thus improving understanding and choice-making among families, service providers and referring agencies.