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: Antonia R. Giannakakos
Caldwell University
Why research this topic?
Research has demonstrated that early intervention is key when a child receives a diagnosis of autism spectrum disorder (ASD). It has also been documented that young children with ASD show atypical patterns in brain activity in response to faces. These atypical patterns are localized in specific regions of the brain and can be measured by calculating the time it takes for those regions to activate in response to different stimuli. These brain patterns are measured using an electroencephalogram (EEG). This study evaluated the effectiveness of the Early Start Denver Model (ESDM), a developmental behavioral intervention, on improving the outcomes of toddlers with ASD by comparing EEG results of toddlers who received ESDM to those of toddlers who received a community intervention and to those of toddlers of typical development.
What did the researcher do?
The researchers compared three groups of toddlers: 15 diagnosed with ASD who received ESDM, 14 diagnosed with ASD who were enrolled in a community intervention (CI) and 17 typically developing toddlers. Nine additional toddlers received ESDM through the study, and 10 additional toddlers received CI. However, these children were unable to complete the EEG assessment. Toddlers in the ESDM group were exposed to 20.4 hours of intervention a week, delivered by a trained therapist supervised by a PhD-level, experienced therapist.
Toddlers in the CI group were exposed to 18.4 hours of intervention a week. The CI intervention was delivered by birth-to-three centers and individual providers and consisted of some combination of speech-language therapy, occupational therapy, and applied behavior analysis (ABA). For both groups, assessments were conducted to evaluate the toddlers’ language, social skills, and autism characteristics. These assessments were conducted prior to the start of intervention and after two years. At the end of the two-year period, the researchers also collected data via EEG on the brain patterns of each toddler in response to faces and items and compared the results of the three groups.
What did the researchers find?
The researchers previously reported that toddlers who received the ESDM intervention had significant improvements in IQ, language, adaptive behavior, and autism characteristics when compared to toddlers in community intervention. Significant differences were observed between the EEG results of the toddlers in the ESDM group and the CI group. Toddlers in the ESDM group demonstrated faster response times to pictures of faces than toddlers in the CI group. The responses of the ESDM group were very similar to those of the toddlers of typical development, suggesting these toddlers showed more attention and allocated more cognitive resources to social stimuli (faces) than to non-social stimuli (items).
What are the strengths and limitations of the study?
Strengths: An important strength of this study is that it included a comparison group of toddlers of typical development. This allowed the researchers to make comparisons between both intervention groups and to children without a diagnosis. A second strength is that the researchers randomly assigned the toddlers with ASD to groups and made sure those groups were equal in terms of IQ score, gender, and child skill level before intervention.
Limitations: A possible confound in this study is the difference in hours per week of intervention between the ESDM and CI groups (20.4 hours in ESDM and 18.4 in CI). While this two-hour difference each week may seem small, it means that toddlers in the CI group received 104 fewer hours of intervention than toddlers in the ESDM group over the course of the two-year study. This discrepancy could be responsible for the EEG differences between the groups. Another limitation is that many toddlers who received ESDM or CI in the study were unable to complete the EEG
What do the results mean?
Overall, the researchers demonstrated that toddlers in ESDM became responsive to social stimuli, as measured by EEG, in comparison to toddlers in CI. However, it is unclear whether these differences reflected the ESDM curriculum or the increased number of intervention hours toddlers in this group received. Also, the large number of participants in ESDM and CI who could not complete the EEG limits the conclusions that can be drawn. Still, the study provides the first evidence that behavioral interventions in ASD can alter brain activity. Moreover, the added evaluation of outcomes using EEG technology is a good step toward objective measurement of behavior changes and may prove useful in future research. Regarding the ESDM, as with all interventions for children with ASD, it is recommended that when determining the effectiveness of one early intervention program over another, parents consider the effectiveness of the program as demonstrated in peer-reviewed research.
Citation for this article:
Giannakakos, A. (2017). Research synopses: Early behavioral intervention is associated with normalized brain activity in young children with autism. Science in Autism Treatment, 14(3), 29-30.
