Tracking the Within-Trial, Cross-Trial, and Developmental Dynamics of Cognitive Control: Evidence From the Simon Task

Six- to 8-year-olds, 10- to 12-year-olds, and adults (N = 108) performed the Simon task by reaching to targets on a digital display. The spatial and temporal characteristics of their movements were used to assess how two key processes underlying cognitive control-a threshold adjustment process and a controlled selection process-unfold over the course of a response (within-trial dynamics), are modulated by recent experience (cross-trial dynamics), and contribute to age-related gains in control (developmental dynamics). The results indicate that the controlled selection process undergoes a more protracted development than the threshold adjustment process. The results also shed light on a prominent debate concerning the cross-trial dynamics of control by supporting the feature integration account over the conflict adaptation account.