Hirano Kanan, Oba Kentaro, Saito Toshiki, Yamazaki Shohei, Kawashima Ryuta, Sugiura Motoaki
Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan.
International Research Institute of Disaster Science, Tohoku University, Sendai 980-8572, Japan.
Cereb Cortex Commun. 2021 Jan 28;2(1):tgab003. doi: 10.1093/texcom/tgab003. eCollection 2021.
Facing one's own death and managing the fear of death are important existential issues, particularly in older populations. Although recent functional magnetic resonance imaging (fMRI) studies have investigated brain responses to death-related stimuli, none has examined whether this brain activation was specific to one's own death or how it was related to dispositional fear of death. In this study, during fMRI, 34 elderly participants (aged, 60-72 years) were presented with either death-related or death-unrelated negative words and asked to evaluate the relevance of these words to the "self" or the "other." The results showed that only the left supplementary motor area (SMA) was selectively activated during self-relevant judgments of death-related words. Regression analyses of the effect of fear of death on brain activation during death-related thoughts identified a significant negative linear correlation in the right supramarginal gyrus (SMG) and an inverted-U-shaped correlation in the posterior cingulate cortex (PCC) only during self-relevant judgments. Our results suggest potential involvement of the SMA in the existential aspect of thoughts of death. The distinct fear-of-death-dependent responses in the SMG and PCC may reflect fear-associated distancing of the physical self and the processing of death-related thoughts as a self-relevant future agenda, respectively.
面对自身死亡并应对对死亡的恐惧是重要的生存问题，在老年人群体中尤为如此。尽管最近的功能磁共振成像（fMRI）研究调查了大脑对与死亡相关刺激的反应，但没有一项研究考察过这种大脑激活是否特定于自身死亡，或者它与对死亡的特质性恐惧有何关联。在本研究中，在fMRI过程中，向34名老年参与者（年龄在60 - 72岁之间）呈现与死亡相关或与死亡无关的负面词汇，并要求他们评估这些词汇与“自我”或“他人”的相关性。结果显示，仅在对与死亡相关词汇的自我相关判断过程中，左侧辅助运动区（SMA）被选择性激活。对与死亡相关想法期间死亡恐惧对大脑激活影响的回归分析表明，仅在自我相关判断期间，右侧缘上回（SMG）存在显著的负线性相关，而后扣带回皮质（PCC）存在倒U形相关。我们的结果表明SMA可能参与了对死亡想法的生存层面。SMG和PCC中不同的死亡恐惧依赖性反应可能分别反映了与恐惧相关的身体自我疏离以及将与死亡相关的想法作为与自我相关的未来议程进行处理。
