Objectives: We investigated the neurobiological mechanisms of CBT by evaluating functional magnetic resonance imaging (fMRI) and electrophysiological (EEG) markers of socioemotional functioning before and after treatment in a 16-year old girl with Asperger Syndrome.
Methods: CBT was adapted from our work in typically developing children (Sukhodolsky et al., 2005, 2009) and consisted of 10 weekly sessions. The ABC irritability subscale (Aman et al., 1985) was completed by the subject’s mother before and after treatment. fMRI and EEG data were collected while the subject performed the frustration-induction Go-NoGo task before and after treatment. The frustration-induction Go-NoGo task represents a mixed blocked/event-related design for fMRI and EEG studies. The subject was asked to view a steady stream of objects and press the button in response to pre-determined experimental conditions. The opportunity to win a prize was manipulated across three conditions with known frustration-induction effects (Perlman and Pelphrey, 2010). We examined changes form pre- to post-treatment in 1) the fMRI blood oxygenation level dependent signal (BOLD) and 2) the amplitude of the Go versus NoGo N2 event related potentials (ERPs) between the neutral versus frustration conditions of the Go-NoGo task.
Results: Parent ratings revealed a decrease in the ABC irritability score from 17 at baseline to 5 at endpoint. The fMRI regions of interest analysis revealed significantly increased activation from pre- to post-treatment in the subgenual anterior cingulate cortex, right ventrolateral prefrontal cortex, and left ventrolateral prefrontal cortex in frustration vs. neutral conditions. The analysis of electrophysiological data revealed a reduction in the difference between NoGo and Go N2 ERPs at post-treatment versus pre-treatment in the frustration condition.
Conclusions: The 12-point change in the ABC irritability score represents a meaningful decline in irritability which is similar to the mean improvement in the medication trials. The fMRI results suggest that brain regions which are recruited in a cognitive task requiring emotion regulation following a period of frustration were hypoactive in the subject before treatment but showed increased activation following treatment with CBT for irritability. The result of the ERP analysis suggests more efficient cognitive control of frustration when performing a response inhibition task after CBT. Thus, reduction of irritability was paralleled by changes in the neural circuitry of emotion regulation. This pilot study supports the feasibility of using fMRI and EEG technology to investigate neurobiological mechanisms of CBT in adolescents with high-functioning ASD.
See more of: Treatments
See more of: Prevalence, Risk factors & Intervention