Complex span tasks and hippocampal recruitment during working memory

► Show that complex span tasks recruit regions typically associated with WM. ► Show they require hippocampal functioning differently than traditional neuroimaging WM tasks. ► Show data that hint at posterior hippocampal specificity. ► Suggest hippocampus may act as temporary storage buffer for items retrieved from LTM. ► Show further support for fronto-cingulo-parietal network in WM.