Fujii Toshikatsu, Suzuki Maki, Okuda Jiro, Ohtake Hiroya, Tanji Kazuyo, Yamaguchi Keiichiro, Itoh Masatoshi, Yamadori Atsushi
Division of Neuropsychology, Department of Disability Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan.
Neuroimage. 2004 Apr;21(4):1596-603. doi: 10.1016/j.neuroimage.2004.01.005.
There has been little evidence for the difference in the retrieval processes of when and where something happened, one of the important factors in understanding episodic memory. We used positron emission tomography (PET) to identify the neural networks associated with temporal and spatial context memory of events experienced under experimental conditions similar to those of everyday life. Before PET, subjects experienced 36 events. The events were divided into four groups of nine each. The subjects experienced the first two groups of events before a 15-min recess and the other two after the recess; they experienced the first and last groups of events in one room, took a recess in another room, and experienced the second and third groups in a different room. During PET, the subjects were scanned under three different retrieval tasks: a time-retrieval task, a place-retrieval task, and a simple recognition task. The results showed that the retrieval of time and space, compared with the simple recognition, was associated with activity in substantially different regions as well as a common region: time retrieval with the posterior part of the right orbitofrontal cortex and left inferior parietal lobule, place retrieval with two regions in right parietal association cortex, right posterior cingulate gyrus, left precentral gyrus, and right cerebellum, and both with the right inferior frontal gyrus. These findings indicate that there are unique areas, in addition to a common area, for retrieving temporal and spatial context.
关于事件发生时间和地点的检索过程存在差异的证据很少，而这是理解情景记忆的重要因素之一。我们使用正电子发射断层扫描（PET）来识别与在类似于日常生活的实验条件下经历的事件的时间和空间背景记忆相关的神经网络。在进行PET扫描之前，受试者经历了36个事件。这些事件被分为四组，每组九个。受试者在15分钟的休息前经历了前两组事件，在休息后经历了另外两组；他们在一个房间里经历了第一组和最后一组事件，在另一个房间里休息，然后在不同的房间里经历了第二组和第三组事件。在PET扫描期间，受试者在三种不同的检索任务下接受扫描：时间检索任务、地点检索任务和简单识别任务。结果表明，与简单识别相比，时间和空间的检索与截然不同的区域以及一个共同区域的活动相关：时间检索与右侧眶额皮质后部和左侧顶下小叶有关，地点检索与右侧顶叶联合皮质的两个区域、右侧后扣带回、左侧中央前回和右侧小脑有关，而两者都与右侧额下回有关。这些发现表明，除了一个共同区域外，还存在用于检索时间和空间背景的独特区域。
