Does prefrontal connectivity during task switching help or hinder children’s performance?

The ability to flexibly switch between tasks is key for goal-directed behavior and continues to improve in late childhood. Children’s task switching difficulties are thought to reflect less efficient engagement of sustained and transient control processes, resulting in lower performance on blocks that intermix tasks (sustained demand) and trials that require a task switch (transient demand). Sustained and transient control processes are associated with frontoparietal regions, which develop throughout childhood and may contribute to task switching development. We examined age differences in the modulation of frontoparietal regions by sustained and transient control demands in children (8–11 years) and adults. Children showed greater performance costs than adults, especially under sustained demand, along with less upregulation of sustained and transient control activation in a set of frontoparietal regions. Compared to adults, children showed greater increases in connectivity between the inferior frontal junction (IFJ) and lateral prefrontal cortex (lPFC) from single to mixed blocks. For children whose sustained activation was less adult-like, increased IFJ-lPFC connectivity was associated with better performance. Children with more adult-like sustained activation showed the inverse effect. Taken together, these results suggest that the configuration of regions that control task switching effectively undergoes developmental changes in later childhood.