Neural indices of improved attentional modulation over middle childhood

The ability to control the focus of attention relies on top-down modulation of cortical activity in areas involved in stimulus processing, and this ability is critical for maintaining items in working memory in the presence of distraction. Prior research demonstrates that children are less capable of focusing attention, relative to adults, and that this ability develops significantly during middle childhood. Here, using fMRI and a face/scene working memory task adapted from Gazzaley et al. (2005a,b), we compared top-down modulation in 15 children (aged 8-13) and 15 young adults (aged 19-26). Replicating prior results, in young adults, attention to scenes modulated activity in the parahippocampal place area (PPA). In addition, modulation of PPA activity increased as a function of age in children. PPA activity was also related to performance in this group, on the working memory task as well on a test of subsequent memory. Dorsolateral PFC also demonstrated increasing task-specific activation, as a function of age, in children. The present findings support the idea that children's reduced ability to maintain items in working memory, especially in the presence of distraction, is driven by weaker top-down modulation of activity in areas involved in stimulus processing. (C) 2010 Elsevier Ltd. All rights reserved.