Post-error slowing and error processing in middle childhood: Evidence for increasing cognitive control adjustment with age

Slowing down one’s response speed following an error, also known as post-error slowing (PES), is a common phenomenon that has been observed in both adults and children as young as 3 to 4 years of age. Despite the pervasive nature of PES, its functional significance, developmental trajectory, and relation with error processing in middle childhood are still debated. This study examined how PES changes throughout middle childhood and relates to neural markers of error processing, Pe amplitude and midfrontal theta (MFT) power. Participants aged 5-12 years (n = 182, 41.8% = female) completed a task-switching paradigm where response times (RTs) and electrophysiological (EEG) data were collected. PES increased with age, primarily on repeat trials. Pe increased after errors in 11-12-year-olds, but not younger children, whereas MFT was elevated post-error across all age groups. MFT power modestly correlated with Pe and, importantly, predicted PES. Greater PES and more efficient error processing with age suggest that PES reflects adaptive adjustment of cognitive control. Keywords: Post-error slowing (PES), error monitoring, cognitive control, Pe, midfrontal theta power, middle childhood.