Cognitive Function In Soldiers Living At High Altitudes

ObjectiveTo investigate the cognitive ability of soldiers at high altitudes, we conducted several experiments using psychological assessments and ERPs method to comparethe cognitive ability, inhibition control function and attention function of soldiersat different altitudes.We explored the cognitive neural characteristics of the good tolerance soldiers at high altitudes. We provided theoretical and empirical evidence for the assessment of cognitive function and mental health of soldiers in the future.MethodsThe research object was divided into the control group and the plateau group. Moved to plateau group somewhere in Tibet(3680 m above sea level, the pressure 358hpa) a unit of soldiers and plain control group in Weinan(an altitude of 500 meters, pressure 1028hPa)soldiers. We collected relevant information with the subjects, covering the age, native place, education and length of military service.The DXC-6 wireless multi type group psychological test instrument were used by us in No.1 experiment. We evaluated the five cognitive functions of the two groups where there are 952 people, such as the digit search test, the test of mental rotation ability, the digit addition test, the memory scanning test, the test of order comprehension.The test results of cognitive ability using T test method to analyze the differences of groups.There were 28 soldiers who have been randomly selected from the plateau group and 28 from the plain groups, would be as the experimental objects of ERPs test in No.2experiment. Then the highest and the lowest score group in the high altitude were selected as the subjects of ERPs test. Go/Nogo task is used in ERPs record. The electroencephalogram(EEG) was continuously recorded at Fz, Cz and Pz sites with NeuroLab amplifier. We recorded the signal of the FZ, CZ and PZ of N2 and P3 wave amplitude and latency. The ANOVAs with repeated measures were conducted for ERP measurements. Greenhouse-Geisser corrections were made when appropriate.The highest and the lowest score group in the high altitude were selected as the subjects of ERPs test in No.3 experiment. Odd-ball task is used in ERPs record. We recorded the signal of the FZ, CZ and PZ of P3 wave amplitude and latency. The ANOVAs with repeated measures were conducted for ERP measurements. Greenhouse-Geisser corrections were made when appropriate.Results No.1 experiment1.Compared with the plain condition, there was higher score(p < 0.01) and faster RT(p<0.01) with the five test in the plateau condition such as the digit search test, the test of mental rotation ability, the digit addition test, the memory scanning test, the test of order comprehension.2. The study found that the cognitive ability of the soldiers in the plateau was significantly higher than the plain, including the five cognitive functions such as the spatial perception ability, judgment ability, short-term memory, attention span and range of language understanding and other.No.2 experimentCompared with the plain condition, the P3 d elicited by Nogo stimuli decreased significantly(p < 0.1), whereas the N2 d did not differ between two groups. Compared with participants with low cognitive function, the P3 d increased significantly(p < 0.1) for participants with high cognitive function.No.3 experimentCompared with participants with low cognitive function, the P3 a elicited by novel stimuli was enhanced significantly(p < 0.1) for participants with high cognitive function.ConclusionsThis study found that the cognitive abilities were significantly higher in the plateau condition than that in plain condition, including spatial perception, judgment, short-termmemory, attention span and scope and language comprehension. These data indicate that in certain conditions of low oxygen can improve some cognitive abilities.The P3 d elicited by Nogo condition was reduced significantly in the plateau than that in the plain condition, indicating the inhibition control is impaired in plateau envioment.In addition, the P3 d was indeed enhanced for the participants with higher cognitive function than those with lower cognitive function.Finally, in plateau condition the frontal-central P3 a reflecting the automatically oritentional response was significantly enhanced for the participants with higher cognitive function than those with lower cognitive function, providing a reliable assessment index for the cognitive function at the specifc altitudes.