Sleep spindle-related reactivation of category-specific cortical regions after learning face-scene associations

► Subjects learned face-scene associations or performed a visuomotor control task. ► EEG-fMRI during subsequent NREM sleep revealed spindle-related brain activation. ► Contrasting learning and control nights revealed spindle-related reactivation. ► Reactivation was restricted to category-specific neocortical sites and hippocampus. ► Reactivation was time-locked to sleep spindles and dependent on their amplitude.