Medial temporal lobe activity associated with active maintenance of novel information

Using event-related functional magnetic resonance imaging, we investigated the role of medial temporal regions during active maintenance of informatio n over short delays or working memory. In experiment 1, we observed sustain ed bilateral hippocampal activation during maintenance of novel faces acros s a short delay period but not during face encoding or recognition. In cont rast, we observed transient right parahippocampal activation during encodin g and recognition but not during maintenance. We replicated these findings in experiment 2 and further determined that anterior hippocampal activation was greater during maintenance of novel than familiar faces. Our results r eveal the importance of medial temporal lobe regions for the active mainten ance of novel information in the absence of perceptual stimulation.