Dawson, G., Jones, E. J., Merkle, K., Venema, K., Lowy, R., Faja, S., . . . Webb, S. J. (2012). Early behavioral intervention is associated with normalized brain activity in young children with autism. Journal of the American Academy of Child and Adolescent Psychiatry, 51(11), 1150-1159.
Reviewed by: Audrey Torricelli,
Rutgers University
Why study this topic?
The Early Start Denver Model (ESDM) is a behavioral intervention for toddlers diagnosed with autism spectrum disorder (ASD). A previous randomized control trial demonstrated that children who received EDSM for two years improved in IQ, language, adaptive behavior, and ASD diagnosis compared to children who received a more commonly available community intervention. The researchers of the current study were interested in how early intervention with ESDM can alter the trajectory of brain development. They hypothesized that the lack of affective and social engagement in children with ASD may hinder behavioral and brain development, and that increasing such engagement through early intervention could lead to a more typical trajectory of brain development.
What did the researcher do?
The researchers recruited young children with a diagnosis of ASD or Pervasive Developmental Disorder (PDD) as well as age-matched typically developing peers. The children with ASD were randomly assigned into either the ESDM group or a community intervention (CI) group. ESDM is a treatment that combines developmental and applied behavior analysis strategies and that involves trained therapists – with experienced PhD-level supervisors – following a manual and curriculum providing 4 hours of intervention twice a day, five days a week, for two years, with additional parent training. The CI group received comprehensive diagnostic evaluations with intervention recommendations, community referrals, and other resources. The researchers also used behavioral measures like the Autism Diagnostic Interview (ADI)-Revised, the Autism Diagnostic Observation Schedule (ADOS), the Mullen Scales of Early Learning (MSEL), the Vineland Scales of Adaptive Behavior, and the Pervasive Developmental Disorder Behavior Inventory (PDDBI) before and after the intervention to assess ASD symptoms and adaptive skills. All child participants in the study also underwent electroencephalography (EEG) observation, with 60% of the participants providing artifact-free (i.e., useable) data. Artifacts were caused primarily by excessive movement or inability to comply with the procedure. During the EEG procedure, children observed unique color photographs of toys and diverse female faces presented randomly on a screen. Researchers were interested in the neural activity in several brain areas while participants engaged in the task.
What did the researchers find?
The researchers found group differences in the central and anterior brain regions of participants when looking at people as compared to objects. The ESDM and typically developing groups showed greater cortical activation for and faster attention to faces, whereas the CI group showed greater activation for and faster attention to objects. These results did not differ by age. While ESDM and typical groups did not differ from one another, the ESDM and CI groups did differ. The researchers also found that ESDM children who provided usable EEG data demonstrated improved autism symptoms, higher verbal and nonverbal IQ, better adaptive skills, and more social behavior with intervention. Greater attention to faces in the ASD groups (ESDM and CI) during the EEG task was correlated with better social communication abilities, and greater brain activation was correlated with fewer social pragmatic problems (like understanding social convention and initiating social interactions).
What are the strengths and limitations of the study? What do the results mean?
The authors suggest that children with ASD may have a delay in developing expertise for face acquisition, but that high rates of intervention can help these children acquire the face-processing abilities of their typically developing peers. This study supports the effectiveness of the ESDM model in developing social attention engagement, as evidenced on both the neural and behavioral levels. There are some limitations to this study: Only about 60% of children with ASD provided artifact-free EEG data, which limits the strength of the study’s conclusions and its applicability to a wide range of children with ASD. Additionally, there was only one time point for EEG measurements; having a pre- and post-intervention design would enable researchers to examine to what degree changes may be attributable to the intervention. Finally, larger samples are needed, and the strength of these findings needs to be verified through replication. Even so, this study suggests that early interventions may have a positive effect on the social development of children with ASD.
Citation for this article:
Torricelli, A. (2018). Research synopses: Early behavioral intervention is associated with normalized brain activity in young children with autism. Science in Autism Treatment, 15(1), 14-15.
