Memory for places learned long ago is intact after hippocampal damage

The hippocampus is part of a system of structures in the medial temporal lo be that are essential for memory(1-3). One influential view of hippocampal function emphasizes its role in the acquisition and retrieval of spatial kn owledge(4,5). By this view, the hippocampus constructs and stores spatial m aps and is therefore essential for learning and remembering places, includi ng those learned about long ago. We tested a profoundly amnesic patient (E. P.), who has virtually complete bilateral damage to the hippocampus and ext ensive damage to adjacent structures in the medial temporal lobe. We asked him to recall the spatial layout of the region where he grew up, from which he moved away more than 50 years ago. E.P. performed as well as or better than age-matched control subjects who grew up in the same region and also m oved away. In contrast, E.P. has no knowledge of his current neighbourhood, to which he moved after he became amnesic. Our results show that the media l temporal lobe is not the permanent repository of spatial maps, and suppor t the view that the hippocampus and other structures in the medial temporal lobe are essential for the formation of long-term declarative memories, bo th spatial and non-spatial, but not for the retrieval of very remote memori es, either spatial or non-spatial(3,6).