Remote spatial memory in an amnesic person with extensive bilateral hippocampal lesions

The hippocampus may have a time-limited role in memory, being needed only u ntil information is permanently stored elsewhere, or this region may perman ently represent long-term allocentric spatial information or cognitive maps in memory. To test these ideas, we investigated remote spatial memory in K .C., a patient with bilateral hippocampal lesions and amnesia for autobiogr aphical events. In his spatial knowledge, general aspects were preserved, b ut details were lost, a pattern that resembled his memory loss in other dom ains. K.C. performed normally on allocentric spatial tests of his neighborh ood and the world. He had difficulty, however, in recognizing and identifyi ng non-salient neighborhood landmarks, and in recognizing city locations on world maps. This suggests that the hippocampus is not crucial for maintena nce and retrieval of remotely formed spatial representations of major landm arks, routes, distances and directions, but is necessary for specifying loc ation details, regardless of when they were acquired.