Constructive episodic simulation: Temporal distance and detail of past and future events modulate hippocampal engagement
Constructive episodic simulation: Temporal distance and detail of past and future events modulate hippocampal engagement
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DOI：
10.1002/hipo.20405
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发表时间：
2008-01-01
期刊：
影响因子：
3.5
通讯作者：
Schacter, Daniel L.
中科院分区：
文献类型：
--
作者：
Addis, Donna Rose;Schacter, Daniel L.
行为、损伤和神经影像学证据显示，记忆过去事件和想象未来事件之间存在惊人的共性。在最近的一项与事件相关的功能磁共振成像研究中，我们指示参与者根据提示构建过去或未来的事件。一旦在脑海中有了一个事件，参与者按下一个按钮，然后生成细节（细化）并对它们进行评级。对过去和未来事件的详细描述需要一个共同的神经网络。然而，该网络中的区域可能对事件特征做出不同的反应，例如生成的细节量和时间距离，这取决于事件是发生在过去还是未来。为了进一步研究这一点，我们进行了参数调制分析，以时间距离和细节为协变量，重点研究内侧颞叶和额极皮层。对细节的分析（与时间距离无关）表明，左后海马体对包括过去和未来事件在内的大量细节都有反应。相比之下，左前海马体对包含未来事件的大量细节的反应不同，这可能反映了细节重组为新的未来事件。时间距离分析显示，过去事件的近代性增加与右侧副海马体回（Brodmann区（BA） 35/36）的活动相关，而双侧海马体的活动与未来事件的距离性增加显著相关。我们认为，海马体对未来事件距离的反应反映了可能包含在遥远未来事件中的细节的日益差异，以及将这些细节整合到未来连贯情景模拟所需的密集关系处理。这些发现为建设性情景模拟假说提供了进一步的支持（Schacter和Addis (2007) Philos Trans R Soc lod B Biol Sci 362:773-786），并强调了海马在阐述未来事件时参与关系处理。(c) 2007 Wiley-Liss, Inc。
Behavioral, lesion and neuroimaging evidence show striking commonalities between remembering past events and imagining future events. In a recent event-related fMRI study, we instructed participants to construct a past or future event in response to a cue. Once an event was in mind, participants made a button press, then generated details (elaboration) and rated them. The elaboration of past and future events recruited a common neural network. However, regions within this network may respond differentially to event characteristics, such as the amount of detail generated and temporal distance, depending on whether the event is in the past or future. To investigate this further, we conducted parametric modulation analyses, with temporal distance and detail as covariates, and focused on the medial temporal lobes and frontopolar cortex. The analysis of detail (independent of temporal distance) showed that the left posterior hippocampus was responsive to the amount of detail comprising both past and future events. In contrast, the left anterior hippocampus responded differentially to the amount of detail comprising future events, possibly reflecting the recombination of details into a novel future event. The analysis of temporal distance revealed that the increasing recency of past events correlated with activity in the right parahippocampus gyrus (Brodmann area (BA) 35/36), while activity in the bilateral hippocampus was significantly correlated with the increasing remoteness of future events. We propose that the hippocampal response to the distance of future events reflects the increasing disparateness of details likely included in remote future events, and the intensive relational processing required for integrating such details into a coherent episodic simulation of the future. These findings provide further support for the constructive episodic simulation hypothesis (Schacter and Addis (2007) Philos Trans R Soc Lond B Biol Sci 362:773-786) and highlight the involvement of the hippocampus in relational processing during elaboration of future events. (c) 2007 Wiley-Liss, Inc.