Department of Psychology, University of Toronto, Toronto, Ontario, Canada.
Hippocampus. 2012 Apr;22(4):842-52. doi: 10.1002/hipo.20944. Epub 2011 May 16.
Functional magnetic resonance imaging (MRI) was used to investigate the hypothesis that memory for a large-scale environment is initially dependent on the hippocampus but is later supported by extra-hippocampal structures (e.g., precuneus, posterior parahippocampal cortex, and lingual gyrus) once the environment is well-learned. Participants were scanned during mental navigation tasks initially when they were newly arrived to the city of Toronto, and later after having lived and navigated within the city for 1 yr. In the first session, activation was observed in the right hippocampus, left precuneus, and postcentral gyrus. The second session revealed activation in the caudate and lateral temporal cortex, but not in the right hippocampus; additional activation was instead observed in the posterior parahippocampal cortex, lingual gyrus, and precuneus. These findings suggest that the right hippocampus is required for the acquisition of new spatial information but is not needed to represent this information when the environment is highly familiar.
功能磁共振成像（fMRI）被用于研究以下假说：对于大范围环境的记忆最初依赖于海马体，但在环境被充分学习后，由海马体以外的结构（如楔前叶、后海马旁回和舌回）来支持。参与者在首次到达多伦多市时和居住并在该城市内导航 1 年后进行了精神导航任务扫描。在第一次会议中，在右侧海马体、左侧楔前叶和后中央回观察到激活。第二次会议显示在尾状核和外侧颞叶皮层有激活，但右侧海马体没有激活；相反，在后海马旁回、舌回和楔前叶观察到额外的激活。这些发现表明，右侧海马体对于获取新的空间信息是必需的，但在环境高度熟悉时，并不需要其来表示该信息。
