Conflict Processing Across Development: The Progression of Response Inhibition Networks

Cognitive control processes allow individuals to guide their behaviour in the face of distracting or irrelevant stimuli, and typically continue developing into early adulthood. These processes are often tested using response inhibition paradigms such as the size congruency task, which require participants to select between conflicting responses. Previous studies have shown that activity in the dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC) parallels the protracted development of cognitive control. Recent evidence suggests that children and adolescents may rely on more subcortical regions such as the cerebellum to process conflict. The present study aimed to comprehensively investigate activity in the DLPFC, ACC, and cerebellum during response inhibition across developmental stages, thereby proposing conflict processing neural pathways utilized at various developmental stages. Five children, five adolescent and five adult participants completed a size congruency task while undergoing fMRI scanning. Incongruent trials (25%) elicited conflict processing. Incongruent-congruent contrasts were averaged within groups and compared across groups via visual inspection. While small regions of unilateral DLPFC activity were measured for children and adolescents, adults showed large regions of bilateral DLPFC activity. Children and adolescents showed no ACC activity while adults exhibited bilateral ACC activity. Children showed more widespread cerebellar activity compared to adolescents and adults. In light of these results and recent research findings, we propose a DLPFC-cerebellar conflict processing network in children, with the cerebellum performing conflict resolution by cancelling an ongoing but incorrect motor program. Adults are suggested to utilize a DLPFC-ACC network, where the ACC suppresses a prepotent response before it is initiated. Adolescents show evidence of activity in both networks. Future studies should focus on how conflict processing develops as a network, rather than identifying localized regions of development. cerebellar pathology in various developmental and neurological conditions including hyperactivity disorder , Tourette’s syndrome and autism 33 . Increased knowledge of the role of the cerebellum in executive functioning and cognitive control, in general, will likely aid in further understanding of the neuropathology of these disorders and may even reveal new therapeutic targets. Finally, the results of the present study suggest a discrepancy in neural pathways underlying response inhibition across developmental stages. While acknowledging that all results presented are based on visual assessment, these findings warrant further investigation into how conflict processing develops as a network, rather than as localized regions of development. Many previous studies have focused on localization of neural regions involved in exerting cognitive control 8,13 . However, as the field of neuroscience leans more towards understanding cognitive processing through network activity 34 , future studies should consider focusing on studying the pathways underlying conflict processing. The results of a similar study conducted on a larger sample may aid in understanding how cognitive control pathways develop, eventually helping researchers treat various disorders associated with improper cognitive control.