Imagining the future: The core episodic simulation network dissociates as a function of timecourse and the amount of simulated information.
Imagining the future: The core episodic simulation network dissociates as a function of timecourse and the amount of simulated information.
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DOI：
10.1016/j.cortex.2017.02.005
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发表时间：
2017-05
期刊：
影响因子：
--
通讯作者：
Schacter DL
中科院分区：
文献类型：
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作者：
Thakral PP;Benoit RG;Schacter DL
神经成像数据表明，情景记忆（即，记住特定的过去经历）和情景模拟（即，想象特定的未来经历）与一组共同的神经区域（通常称为核心网络）的增强活动有关。该网络包括海马、海马旁皮质、外侧和内侧顶叶皮质、外侧颞叶皮质和内侧前额叶皮质。核心网络的证据已被视为支持情景记忆和情景模拟是由共同的过程支持的想法。关于特定的核心网络区域如何对情景模拟的特定方面做出贡献，还有很多东西有待了解。先前对情景记忆的神经成像研究表明，核心网络内的某些区域对回忆的信息量具有不同的敏感性（例如，左侧顶叶皮层）。此外，某些核心网络区域在情景记忆期间作为其参与时间过程的函数而解离（例如，后海马体中的瞬时活动和左外侧顶叶皮质中的持续活动）。在目前的研究中，我们评估了在情景模拟中是否可以观察到类似的解离。我们发现，左侧顶叶皮层的调制作为模拟细节的量的函数。特别感兴趣的是，虽然海马是不敏感的模拟细节的量，我们观察到海马内的时间分离：短暂的活动发生在相对较后的海马和持续的活动发生在前部。由于后海马和侧顶叶的研究结果与先前在情景记忆中观察到的结果平行，因此本研究结果增加了情景记忆和情景模拟得到共同过程支持的证据。重要的是，本研究还提供了证据，核心网络内的区域支持分离的过程。
Neuroimaging data indicate that episodic memory (i.e., remembering specific past experiences) and episodic simulation (i.e., imagining specific future experiences) are associated with enhanced activity in a common set of neural regions, often referred to as the core network. This network comprises the hippocampus, parahippocampal cortex, lateral and medial parietal cortex, lateral temporal cortex, and medial prefrontal cortex. Evidence for a core network has been taken as support for the idea that episodic memory and episodic simulation are supported by common processes. Much remains to be learned about how specific core network regions contribute to specific aspects of episodic simulation. Prior neuroimaging studies of episodic memory indicate that certain regions within the core network are differentially sensitive to the amount of information recollected (e.g., the left lateral parietal cortex). In addition, certain core network regions dissociate as a function of their timecourse of engagement during episodic memory (e.g., transient activity in the posterior hippocampus and sustained activity in the left lateral parietal cortex). In the current study, we assessed whether similar dissociations could be observed during episodic simulation. We found that the left lateral parietal cortex modulates as a function of the amount of simulated details. Of particular interest, while the hippocampus was insensitive to the amount of simulated details, we observed a temporal dissociation within the hippocampus: transient activity occurred in relatively posterior portions of the hippocampus and sustained activity occurred in anterior portions. Because the posterior hippocampal and lateral parietal findings parallel those observed previously during episodic memory, the present results add to the evidence that episodic memory and episodic simulation are supported by common processes. Critically, the present study also provides evidence that regions within the core network support dissociable processes.