Neural indicators of error processing and intraindividual variability in reaction time in 7 and 9 year-olds

Childhood is associated with improvements in task accuracy, response time, and reductions in intraindividual trial-to-trial variability in reaction times. The aims of this study were to investigate neural indicators of error monitoring to better understand the mechanisms underlying these cognitive developments in primary school aged children. Specifically, this study explored the development of error processing in 36 children aged 7 years and 41 children aged 9 years, as indexed by two electrophysiological indices of error processing, the error-related negativity (ERN) and the error positivity (Pe). Notably, the amplitude and latency of the ERN and Pe did not differ significantly between the age groups. However, intraindividual variability in response time (RT) was strongly related to ERN amplitude. These data suggest the utility of comparing neural and behavioral indicators of cognitive performance in children and uniquely highlight the importance of considering intraindividual variability in task performance in studies that explore error processing.