Source localization of the Nogo-N2: A developmental study

Objective The aim of the present study was to investigate whether similar neural sources are involved in generating Nogo-N2 scalp topography in children and adults. Methods Source analysis was performed on the Nogo-N2 data from two groups of children (sixteen 6/7 year-olds and seventeen 9/10 year-olds) and seventeen young adults (aged 19–23 years) that were obtained in a prior study by Jonkman LM. The development of preparation, conflict monitoring and inhibition from early childhood to young adulthood; a go/nogo ERP study. Brain Res 2006;1097:181–93. Results In both children and adults a bilateral source pair in the medial frontal cortex (near ACC) was involved in the generation of Nogo-N2 activity. However, children needed an additional, posteriorly located source pair to adequately explain the Nogo-N2 distribution. In 6/7 year-olds this posterior source was localized in occipito-temporal areas, whereas in 9/10 year-olds the posterior sources shifted to parietal locations. Conclusions Although children recruit similar frontal regions as adults in the Nogo-N2 time window, the additional activation of posterior sources might indicate that early executive control performance is less automatic or requires more effortful control in children. This in turn might cause them to rely on more basic stimulus processing or to activate additional attention-related areas. Significance Results from the present study show that in children, a more diffuse brain network is involved in executive control processing (conflict monitoring) in the Nogo-N2 time window than in adults.