Efficacy of Brief Pivotal Response Training on Language Outcomes and Neurophysiological Indices in Children with ASD

Background:  Behavioral interventions are robustly supported in the treatment of ASD, including those that are parent-administered. Few studies have explored the efficacy of brief parent training models and the effects on child functioning. Further, little is understood regarding the impact of behavioral treatments on neurophysiological functioning. Pivotal Response Training (PRT) is an empirically supported, naturalistic behavioral approach, typically delivered via 25 or more parent training hours. Few studies have examined more brief models of PRT. Additionally, while evidence suggests behavioral interventions alter brain functioning in animal models, recent work suggests behavioral interventions for ASD (e.g., Early Start Denver Model) may also change neurological functioning; however, studies examining the effects of PRT on brain function are just emerging.

Objectives:  This study examined the effect of brief (12-week) PRT on child language functioning. As an exploratory objective, correlated brain activity was examined in an additional group of participants by assessing neurophysiological indices of language skills.

Methods:  In this uncontrolled trial, efficacy of parent-delivered PRT was examined to address language impairment in children with ASD, ages 3 to 7 years. Thirteen families have completed the protocol across two sites to date. Data collection is ongoing. Parent-child dyads participated in 12 weekly, 60-minute PRT parent training sessions, with a focus on child language gains. Data were obtained at baseline and post-treatment, using systematic scoring by independent raters of target behaviors observed during 10-minute video-taped structured lab observations (SLO). The primary dependent variable was child functional utterances during the SLO.  These data were analyzed using paired t-tests to examine changes from pre- to post-treatment. For a small number of additional participants, high density EEG was collected during observation of social and nonsocial videos. Cortical activation, as reflected in spectral power in alpha and theta bands during the observation of social and nonsocial stimuli, was assessed to examine changes over treatment. For these children, a multiple baseline design across participants was used to examine child functional utterances and EEG data.

Results:  Preliminary findings suggest parent training in PRT was associated with child language improvements (N=9), with a significant increase in functional utterances from baseline (34.2 ± 31) to post-treatment (55.9 ± 34) (t = -2.922; df =8; p= 0.019). Adequate, artifact free EEG was obtained from three of four additional participants. A multiple baseline design across participants indicated similar improvements in functional utterances and preliminary EEG findings indicate more normalized cortical activation (decreased alpha power and increased theta power) when viewing faces relative to objects following intervention.

Conclusions: Findings from this pilot study suggest brief parent training in PRT is associated with improvement in child language skills. Further, EEG findings support that these behavioral changes, following short-term PRT, are mirrored in changes in neurophysiological functioning to more normalized neural activity. These findings are analyzed in light of the need for more cost-effective and efficient treatment models and better understanding the impact of behavioral interventions on neurophysiological functioning in children with ASD.