State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China.
PLoS One. 2012;7(7):e40316. doi: 10.1371/journal.pone.0040316. Epub 2012 Jul 5.
Time discounting refers to the fact that the subjective value of a reward decreases as the delay until its occurrence increases. The present study investigated how time discounting has been affected in survivors of the magnitude-8.0 Wenchuan earthquake that occurred in China in 2008.
Nineteen earthquake survivors and 22 controls, all school teachers, participated in the study. Event-related brain potentials (ERPs) for time discounting tasks involving gains and losses were acquired in both the victims and controls.
The behavioral data replicated our previous findings that delayed gains were discounted more steeply after a disaster. ERP results revealed that the P200 and P300 amplitudes were increased in earthquake survivors. There was a significant group (earthquake vs. non-earthquake) × task (gain vs. loss) interaction for the N300 amplitude, with a marginally significantly reduced N300 for gain tasks in the experimental group, which may suggest a deficiency in inhibitory control for gains among victims.
The results suggest that post-disaster decisions might involve more emotional (System 1) and less rational thinking (System 2) in terms of a dual-process model of decision making. The implications for post-disaster intervention and management are also discussed.
时间折扣是指奖励的主观价值随着延迟时间的增加而减少的现象。本研究调查了 2008 年中国汶川 8.0 级地震幸存者的时间折扣情况。
19 名地震幸存者和 22 名对照组（均为学校教师）参与了本研究。在受害者和对照组中都获得了涉及收益和损失的时间折扣任务的事件相关脑电位（ERP）。
行为数据复制了我们之前的发现，即灾难后延迟收益的折扣幅度更大。ERP 结果显示，地震幸存者的 P200 和 P300 振幅增加。N300 振幅存在显著的组（地震幸存者与非地震幸存者）×任务（收益与损失）交互作用，实验组的收益任务的 N300 振幅明显降低，这可能表明受害者在收益方面的抑制控制能力不足。
结果表明，根据决策的双系统模型，灾后决策可能更多地涉及情绪（系统 1），而较少涉及理性思维（系统 2）。还讨论了灾后干预和管理的意义。
