期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：50
页码：14289-14293
DOI：10.1073/pnas.1617786113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceThe hippocampus has been linked to both memory and spatial cognition, but these ideas are not entirely compatible. We administered navigation tasks in which participants transformed map coordinates into geographical coordinates to follow paths indicated on maps. Patients with limited hippocampal lesions performed normally. A patient with large lesions that damaged the hippocampus as well as the adjacent parahippocampal gyrus was impaired. All the patients were impaired at remembering facts about the task. The findings suggest that the spatial computations needed for navigating from maps are independent of the hippocampus. The impairment after large medial temporal lobe lesions may result from damage to the posterior parahippocampal gyrus. The findings emphasize the importance of the hippocampus for memory functions. We administered map-reading tasks in which participants navigated an array of marks on the floor by following paths on hand-held maps that made up to nine turns. The burden on memory was minimal because the map was always available. Nevertheless, because the map was held in a fixed position in relation to the body, spatial computations were continually needed to transform map coordinates into geographical coordinates as participants followed the maps. Patients with lesions limited to the hippocampus (n = 5) performed similar to controls at all path lengths (experiment 1). They were also intact at executing single moves to an adjacent location, even when trials began by facing in a direction that put the map coordinates and geographical coordinates into conflict (experiment 2). By contrast, one patient with large medial temporal lobe (MTL) lesions performed poorly overall in experiment 1 and poorly in experiment 2 when trials began by facing in the direction that placed the map coordinates and geographical coordinates in maximal conflict. Directly after testing, all patients were impaired at remembering factual details about the task. The findings suggest that the hippocampus is not needed to carry out the spatial computations needed for map reading and navigating from maps. The impairment in map reading associated with large MTL lesions may depend on damage in or near the parahippocampal cortex.
