Effects of rTMS on Behavioral and Electrocortical Measures of Error Monitoring and Correction Function in Children with Autism Spectrum Disorder

Abstract

Error monitoring and correction is one of the executive functions and is important for effective goal-directed behavior. Deficient executive functioning, including reduced error monitoring ability, is one of the typical features of such neurodevelopmental disorders as autism spectrum disorder (ASD), probably related to perseverative responding, stereotyped repetitive behaviors, and an inability to accurately monitor ongoing behavior. Our prior studies of behavioral and event-related potential (ERP) measures during performance on visual oddball tasks in high-functioning autistic children showed that despite only minor differences in reaction times (RT) children with autism committed significantly more errors. The chapter reviews behavioral (reaction time, accuracy, rate of omission and commission errors, post-error reaction time slowing) error monitoring in children with ASD and response-locked event-related potentials (ERP), in particular, the error-related negativity (ERN) and error-related positivity (Pe) recorded at the fronto-central EEG sites. The ERN reflects early error detection processes, whereas the Pe has been associated with later conscious error evaluation and attention reallocation. Our prior studies showed significant differences of behavioral and ERN indices between children with ASD and with ADHD as well as with typical developing peers. The goal of our chapter is to review effects of slow frequency repetitive TMS (rTMS) over dorsolateral prefrontal cortex (DLPFC) in high-functioning children with ASD on behavioral and electrocortical measures found in a series of studies conducted by our group. Our results show significant post-TMS differences in the response-locked ERPs such as ERN, as well as behavioral response-monitoring measures indicative of improved error monitoring and correction function. Our review suggests that TMS has the potential to become a viable therapeutic tool in ASD treatment and may play an important role in improving the quality of life of many children with the disorder. The chapter provides rationale to use ERN and Pe, along with behavioral performance measures as functional outcome measures, to assess the effectiveness of neuromodulation (e.g., rTMS and rTMS combined with neurofeedback) in children with autism, and thus, may have important practical implications.