长期高原环境暴露对知觉闭合功能的影响

Effects of long-term exposure to high altitudes on perceptual closure

目的:考察长期高原环境暴露影响知觉闭合功能加工过程的神经机制。方法:采用横断面研究,选取30名首次进入高原地区(海拔3658米)并居住满两年的大学生作为高原组,另选年龄、性别和教育程度相匹配的29名从未去过高原地区的大学生作为平原组,比较两组被试的基本生理指标。两组被试接受面孔成对比较任务,采用事件相关电位(event-related potentials,ERPs)技术比较两组被试脑电数据的差异。采用SPSS 22.0软件进行统计分析,采用均数±标准差进行统计描述,两组被试生理数据的比较采用独立样本t检验,脑电数据的比较采用重复测量方差分析。结果:生理学指标显示,高原组大学生的心率[(86.71±10.82)次/min,(75.97±11.28)次/min;t=-3.19,P=0.002]、舒张压[(75.93±9.19)mmHg,(68.59±11.42)mmHg);t=-3.20,P=0.002]均显著高于平原组;高原组大学生的血氧饱和度显著低于平原组[(90.77±2.25)%,(98.31±1.56)%;t=14.00,P<0.001]。在面孔成对比较任务中,事件相关电位的P1波潜伏期组别主效应显著,高原组大学生显著短于平原组[(105.10±15.59)ms,(128.35±14.40)ms,P<0.001]。N170波幅组别主效应显著,高原组波幅显著大于平原组[(-7.57±3.83)μV,(-5.11±3.26)μV,P=0.005]。NCL波幅组别和半球交互效应显著(F(1,57)=9.72,P=0.003),简单效应检验显示,平原组右侧波幅显著大于左侧[(0.46±1.31)μV,(1.16±1.33)μV]。P1潜伏期与心率(r=-0.46,P<0.01)、血氧饱和度(r=0.64,P<0.01)和舒张压(r=-0.26,P=0.049)均显著相关。结论:长期暴露于高原环境,视觉早期感知的神经反应活动加快,在面孔整体构型加工阶段激活了更多神经元,在知觉闭合完成阶段出现半球代偿效应。

Objective To investigate the neural mechanism of long-term exposure to high altitudes environment on the processing stage of perceptual closure.Methods A cross-sectional study was conducted.Thirty college students who first entered the plateau area(at an altitude of 3658 m)and had lived in high-altitude areas for two years were selected as high altitude group(HA group),and 29 college students matched in age,gender and education level who had never been to the plateau area were selected as sea level group(SL group).The differences of basic physiological parameters were compared between the two groups.The face pairwise comparison paradigm was applied in the subjects of the two groups and the differences between the two groups were compared by event-related potentials(ERPs)technology.SPSS 22.0 software was used for statistical analysis,and the mean±standard deviation was used for statistical description.Independent sample t test was used for comparison of physiological data between the two groups,and repeated measurement variance analysis was used for ERP data.Results The physiological results revealed that the HA group had a higher pulse rate((86.71±10.82)/min,(75.97±11.28)/min;t=-3.19,P=0.002)and diastolic blood pressure than the SL group((75.93±9.19)mmHg,(68.59±11.42)mmHg;t=-3.20,P=0.002).The oxygen saturation level was significantly lower than that of SL group((90.77±2.25)%,(98.31±1.56)%);t=14.00,P<0.001).In the face pairwise comparison paradigm test,the main effect of P1 latency of ERP was significant.Compared with SL group,HA group showed significantly shortened latency of P1((105.10±15.59)ms,(128.35±14.40)ms,P<0.001).The main effect of group of N170 amplitude was significant,HA group was larger than that of SL group((-7.57±3.83)μV,(-5.11±3.26)μV,P=0.005).The interaction effect between group and hemisphere of NCL amplitude was significant(F(1,57)=9.72,P=0.003).Simple effect test showed that the amplitude on the right hemisphere of SL group was significantly larger than that on the left hemisphere((0.46±1.31)μV),(1.16±1.33)μV).The latency of P1 was significantly correlated with heart rate(r=-0.46,P<0.01),oxygen saturation level(r=0.64,P<0.01)and diastolic blood pressure(r=-0.26,P=0.049).Conclusion After long-term exposure to high altitude,the neural response related to early visual perception is faster.More psychological resources are recruited during the face structural encoding stage.Contra-lateral compensating effect appeares in the stage of perceptual closure.