Department of Psychological and Brain Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA.
VISN 17 Center of Excellence for Research on Returning War Veterans, Waco, TX 76711, USA; Center for Vital Longevity, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX 75235, USA; Department of Psychology and Neuroscience, Baylor University, Waco, TX 76789, USA.
Neuropsychologia. 2018 Feb;110:180-189. doi: 10.1016/j.neuropsychologia.2017.06.016. Epub 2017 Jun 15.
The relation between episodic memory and episodic future thought (EFT) remains an active target of research. A growing literature suggests that similar cognitive processes and neural substrates tend to support these acts. However, direct comparisons of whole-brain activity reveal clear differences, with numerous regions more active when engaging in EFT than when remembering, and a smaller collection of regions displaying the opposite pattern of activity. Although various network labels have been applied to prior neuroimaging results, to date no formal resting-state functional connectivity analysis has been conducted. In the current experiment, 48 subjects remembered events from their past and engaged in EFT. Resting-state data were collected from all subjects. Task results replicated recent findings, with more activity during EFT in regions across frontal and parietal cortex, and with more activity during remembering in a smaller number of predominantly parahippocampal and retrosplenial regions. Resting-state connectivity analysis, based on seed locations defined using the fMRI task data, indicated that regions preferentially activated during EFT fell primarily within the default mode network, while those more active during remembering fell primarily within the contextual association network. These results suggest that despite their general similarity, the functional network membership of regions showing task differences is dissociable. We discuss our results in light of several hypotheses that attempt to relate remembering and EFT, and suggest that the data speak to differences in the relative contributions of episodic and semantic memory, as well as controlled and automatic processing, during the acts of remembering or engaging in EFT.
情景记忆和情景未来思维（EFT）之间的关系仍然是研究的活跃目标。越来越多的文献表明，相似的认知过程和神经基质倾向于支持这些行为。然而，对全脑活动的直接比较显示出明显的差异，在进行 EFT 时，许多区域比在回忆时更活跃，而只有一小部分区域显示出相反的活动模式。尽管先前的神经影像学结果已经应用了各种网络标签，但迄今为止，还没有进行正式的静息状态功能连接分析。在当前的实验中，48 名被试回忆过去的事件并进行 EFT。所有被试的静息状态数据都被收集。任务结果复制了最近的发现，在 EFT 期间，前额叶和顶叶皮层的多个区域活动增加，而在回忆期间，活动增加的区域数量较少，主要位于海马旁回和后扣带回区域。基于使用 fMRI 任务数据定义的种子位置的静息状态连接分析表明，在 EFT 期间优先激活的区域主要位于默认模式网络内，而在回忆期间优先激活的区域主要位于上下文关联网络内。这些结果表明，尽管它们具有一般相似性，但表现出任务差异的区域的功能网络成员是可分离的。我们根据几个试图将回忆和 EFT 联系起来的假设讨论了我们的结果，并提出数据表明在回忆或进行 EFT 时，情景记忆和语义记忆以及控制和自动处理的相对贡献存在差异。
