Developmental disparities between stimulus-response and stimulus-stimulus conflicts processing during childhood, adolescence, and early adulthood

Conflict control is a critical capability for humans to detect and resolve conflicts. Unbalanced development of cognitive control may be associated with mental disorders and cause a heavy social burden. Despite the substantial amount of research on this topic, inconsistent conclusions were obtained from developmental trajectories of stimulus-response (S-R) conflict processing and stimulus-stimulus (S-S) conflict processing. This may be due to different tasks or relatively small population-based samples. Therefore, we designed a Simon-spatial-Stroop task and recruited 644 children, adolescents, and young adults from ages 7 to 23 to investigate consecutively developmental trajectories of different types of conflict processing. Our results demonstrated that all age groups showed robust stimulus-response compatibility (SRC) effects, and the task performance improved with faster response speed and enhanced accuracy with advancing age. It is noteworthy that the size of both S-R and S-S SRC effects declined from ages 7 to 15, which suggested that the crucial developmental period is from early childhood to adolescence. Furthermore, both S-R and S-S conflicts processing followed a U-shaped function across ages and showed a distinct developmental pattern from age 7. The peak performance of S-S conflict processing (18.61 years) occurred earlier than S-R conflict processing (19.66 years), suggesting S-S conflict processing may mature earlier than S-R conflict processing. The current study provides a robust measurement of conflict control across a wide age range and advances our understanding of the developmental specificity of S-R and S-S conflict processing.