认知与发展心理学研究室知识库

随着国家全面建设发展，到青藏高原地区旅游、工作和生活者越来越多。长期高原缺氧环境降低心理功能。本研究基于认知资源有限理论，采用测试认知灵活性的任务转换范式，结合事件相关电位技术和静息态脑电技术，探讨长期高原缺氧环境对认知灵活性及静息态脑电各频段功率值的影响。
研究包含两个实验。实验一，比较 25名从低海拔地区移居到高原地区生活满3 年的西藏大学学生和25名从未到过高原地区的同龄大学生完成任务转换范式的情况并同时记录其脑电数据，考察长期高原缺氧环境对认知灵活性的影响；实验二，采集 37 名在高原地区生活满 3 年的西藏大学学生和 37 名从未到过高原地区的同龄大学生无任务状态下的静息态脑电数据，并计算各特征频段的脑电功率值，考察长期高原缺氧对各频段特别是α、β波活动的影响。研究发现：
1. 完成任务转换范式时，高原组仅颜色任务反应时长于平原组（p＜0.05），形状任务反应时、混合序列反应时、混合序列中转换任务及重复任务反应时、转换代价、混合代价均无组间差异；正确率亦均无组间差异。
2. 提示物锁定时间窗口脑电分析中，FPz、Cz电极 P2成分波峰值高原组大于平原对照组，高海拔效应显著，表明其完成任务时投入更多注意资源。
3. 刺激物锁定时间窗口脑电分析中， 高原组 P2成分波峰值亦比平原对照组大（p＜0.05），表明其对刺激物对应的反应规则检索时施加了更多努力。高原组被试完成任务转换范式时， 顶枕区头皮电极P3成分平均波幅较平原对照组低，表明高原组被试在完成任务时占用更多认知资源。
4. 静息态脑电表明高原组被试与多种认知功能相关的α波受长期高原缺氧影响， 活动减弱 （α1： p＜0.05） ； 与注意功能相关的β波活动增强 （β1： p＜0.05） 。
结论：长期高原缺氧环境影响认知灵活性，完成任务转换范式时需要占用更多认知资源；但人产生补偿机制（即大脑皮层兴奋性增强，注意力提高），帮助其完成任务转换范式且与平原对照组表现相当。

With the country's overall construction and development, people going to the Qinghai-Tibet plateau for tourism and work are increasing. Long term high altitude hypoxia environment can reduce the psychological function. This thesis based on the cognitive theory of limited resources, using task-switching paradigm to test cognitive flexibility, combining ERP and EEG-resting state to investigate the long-term hypoxia environment’s effects on cognitive flexibility and its effect on the power of each frequency band of EEG-resting state.
With the country's overall construction and development, people going to the Qinghai-Tibet plateau for tourism and work are increasing. Long term high altitude hypoxia environment can reduce the psychological function. This thesis based on the cognitive theory of limited resources, using task-switching paradigm to test cognitive flexibility, combining ERP and EEG-resting state to investigate the long-term hypoxia environment’s effects on cognitive flexibility and its effect on the power of each frequency band of EEG-resting state.
1. The plateau group has longer reaction time than the control group in single color task (p<0.05), there are no significant differences in reaction time between the
groups in mix task, switching task, repeat task, switch cost and mix cost. Correct rate has no differences between groups in any task.
2. Cue-locked time window analysis find that P2 peak in FPz, Cz electrodes have high altitude effect, plateau group higher than plain control group, with that plateau subjects use more attention.
3. Stimulus-locked time window, plateau group has higher P2 peak than plain control group (p<0.05), indicating more effort are carried out. When the plateau group complete the task-switching paradigm, the average amplitude of P3 is lower than that of the plain control group (p<0.05), indicating that the plateau group invest more cognitive resources during the task.
4. The resting-EEG show that activity of alpha band decreased in plateau group due to long-term hypoxia (α1: p＜0.05); the activity of attention related beta band increased (β1: p＜0.05).
Conclusion: Long term hypoxia in high altitude can impair cognitive flexibility, more cognitive resources are needed to complete the task-switching paradigm. However, the long-term hypoxia environment causes a compensation mechanism, enhance the cerebral cortex excitability and increase attention in order to complete the task-switching paradigm and act as same as the plain group.