Learning and remembering real-world events after medial temporal lobe damage

Significance We explored the role of the medial temporal lobe (MTL) in remembering recent events. Patients with MTL damage and healthy controls were taken on a walk during which 11 planned events occurred. Patients remembered fewer details about the events than controls. Nevertheless, the details made reference to particular places and events from the walk. In addition, patients were similarly impaired across different kinds of content (spatial and nonspatial). Last, the patients were particularly impaired at remembering the temporal order in which the events occurred. The findings illuminate the role of the MTL in memory for real-world events and in the spatial and nonspatial aspects of recollection. The hippocampus is important for autobiographical memory, but its role is unclear. In the study, patients with hippocampal damage and controls were taken on a 25-min walk on the University of California, San Diego, campus during which 11 planned events occurred. Memory was tested directly after the walk. In addition, a second group of controls took the same walk and were tested after 1 mo. Patients with hippocampal damage remembered fewer details than controls tested directly after the walk but remembered a similar number of details as controls tested after 1 mo. Notably, the details that were reported by patients had the characteristics of episodic recollection and included references to particular places and events. Patients exhibited no special difficulty remembering spatial details in comparison with nonspatial details. Last, whereas both control groups tended to recall the events of the walk in chronological order, the order in which patients recalled the events was unrelated to the order in which they occurred. The findings illuminate the role of the hippocampus in autobiographical memory and in the spatial and nonspatial aspects of episodic recollection.