Department of Physiology, The University of Tokyo School of Medicine, Bunkyo-ku, Tokyo 113, Japan.
Neuroimage. 2010 Feb 15;49(4):3474-80. doi: 10.1016/j.neuroimage.2009.11.003. Epub 2009 Nov 10.
There is a growing interest in the parietal cortical role for episodic memory retrieval. Previous functional magnetic resonance imaging (fMRI) studies of recency judgments, judgments of the relative temporal order of two studied items, have highlighted the involvement of the lateral prefrontal and medial temporal regions. However, the parietal cortical contribution to recency judgments has rarely been highlighted. To examine the parietal involvement, in this study, we conducted a re-analysis to increase the statistical power using three data sets (N=73) from our previous fMRI studies of recency judgments. Recency judgments can be achieved by at least two mechanisms, relational and item-based ones. It has been revealed that the left hippocampus/parahippocampal region is related to relational recency judgments, and that the right anterior temporal region is related to item-based recency judgments. We examined whether the parietal cortex is involved in these two types of recency judgments. Significant brain activity related to relational recency judgments was observed in the left ventral parietal region and, as reported previously, the left parahippocampal region. On the other hand, significant brain activity related to item-based recency judgments was observed in the left dorsal parietal region and, as reported previously, the right anterior temporal region. Furthermore, correlation analyses of resting-state BOLD signals detected significant correlations between the ventral parietal region and the parahippocampal region, as well as between the dorsal parietal region and anterior temporal region. These results suggest that the two temporo-parietal networks differentially contribute to relational and item-based recency judgments.
人们对顶叶皮质在情节记忆检索中的作用越来越感兴趣。先前关于最近事件判断（判断两个学习项目的相对时间顺序）的功能磁共振成像（fMRI）研究强调了外侧前额叶和内侧颞叶区域的参与。然而，最近事件判断中顶叶皮质的贡献很少被强调。为了研究顶叶的参与，在这项研究中，我们使用了我们之前关于最近事件判断的三项 fMRI 研究的三个数据集（N=73）进行了重新分析，以增加统计功效。最近事件判断可以通过至少两种机制来实现，即关系和基于项目的机制。已经揭示了左海马/海马旁回区域与关系最近事件判断有关，而右前颞区与基于项目的最近事件判断有关。我们检查了顶叶皮质是否参与这两种类型的最近事件判断。与关系最近事件判断相关的显著大脑活动在左腹侧顶叶区域中观察到，如前所述，在左海马旁回区域中也观察到了显著大脑活动。另一方面，与基于项目的最近事件判断相关的显著大脑活动在左背侧顶叶区域中观察到，如前所述，在右前颞区中也观察到了显著大脑活动。此外，静息态 BOLD 信号的相关分析检测到腹侧顶叶区域与海马旁回区域之间以及背侧顶叶区域与前颞区域之间存在显著相关性。这些结果表明，两个颞顶网络对关系和基于项目的最近事件判断有不同的贡献。
