Resistance to forgetting

Although it is well established that successful encoding of new episodic memories is dependent on the hippocampus, a variety of factors determine whether memories will ultimately be remembered or forgotten. The risk of forgetting is higher when followed by similar or overlapping experiences, creating interference between the past and the present. The authors present evidence showing that the hippocampus is involved in minimizing the forgetting that is brought about by new learning. Specifically, the hippocampus appears to accomplish this by reactivating older memories as new memories are formed.
Kuhl BA et al.: Resistance to forgetting associated with hippocampus-mediated reactivation during new learning. Nature Neuroscience 13: 501-506 (2010).
http://www.ncbi.nlm.nih.gov/pubmed/20190745