Department of Psychology and Neuroscience, Duke University, USA; Center for Cognitive Neuroscience, Duke University, USA.
Department of Psychology and Neuroscience, Duke University, USA; Center for Cognitive Neuroscience, Duke University, USA.
Neuroimage. 2018 Sep;178:332-345. doi: 10.1016/j.neuroimage.2018.05.053. Epub 2018 May 25.
Counterfactual thinking (CFT) is the process of mentally simulating alternative versions of known facts. In the past decade, cognitive neuroscientists have begun to uncover the neural underpinnings of CFT, particularly episodic CFT (eCFT), which activates regions in the default network (DN) also activated by episodic memory (eM) recall. However, the engagement of DN regions is different for distinct kinds of eCFT. More plausible counterfactuals and counterfactuals about oneself show stronger activity in DN regions compared to implausible and other- or object-focused counterfactuals. The current study sought to identify a source for this difference in DN activity. Specifically, self-focused counterfactuals may also be more plausible, suggesting that DN core regions are sensitive to the plausibility of a simulation. On the other hand, plausible and self-focused counterfactuals may involve more episodic information than implausible and other-focused counterfactuals, which would imply DN sensitivity to episodic information. In the current study, we compared episodic and semantic counterfactuals generated to be plausible or implausible against episodic and semantic memory reactivation using fMRI. Taking multivariate and univariate approaches, we found that the DN is engaged more during episodic simulations, including eM and all eCFT, than during semantic simulations. Semantic simulations engaged more inferior temporal and lateral occipital regions. The only region that showed strong plausibility effects was the hippocampus, which was significantly engaged for implausible CFT but not for plausible CFT, suggestive of binding more disparate information. Consequences of these findings for the cognitive neuroscience of mental simulation are discussed.
反事实思维（CFT）是一种在心理上模拟已知事实的替代版本的过程。在过去的十年中，认知神经科学家开始揭示 CFT 的神经基础，特别是情景 CFT（eCFT），它激活了默认网络（DN）中的区域，这些区域也被情景记忆（eM）回忆激活。然而，对于不同类型的 eCFT，DN 区域的参与是不同的。与不太可能的和其他的或对象为中心的反事实相比，更合理的反事实和关于自己的反事实在 DN 区域显示出更强的活动。本研究旨在确定 DN 活动差异的一个来源。具体来说，自我中心的反事实可能也更合理，这表明 DN 核心区域对模拟的合理性敏感。另一方面，合理的和自我中心的反事实可能比不合理的和其他中心的反事实包含更多的情景信息，这意味着 DN 对情景信息敏感。在目前的研究中，我们使用 fMRI 比较了生成的合理或不合理的情景和语义反事实与情景和语义记忆再激活。采用多元和单变量方法，我们发现 DN 在情景模拟中比在语义模拟中更活跃，包括 eM 和所有 eCFT。语义模拟更多地参与了下颞叶和外侧枕叶区域。唯一表现出强烈合理性效应的区域是海马体，它对不合理的 CFT 有明显的参与，但对合理的 CFT 没有参与，表明它结合了更多不同的信息。这些发现对心理模拟的认知神经科学的影响进行了讨论。
