Oxygen Metabolism-induced Stress Response Underlies Heart-brain Interaction Governing Human Consciousness-breaking and Attention / 神经科学通报·英文版

Neuroscientists have emphasized visceral influences on consciousness and attention, but the potential neurophysiological pathways remain under exploration. Here, we found two neurophysiological pathways of heart-brain interaction based on the relationship between oxygen-transport by red blood cells (RBCs) and consciousness/attention. To this end, we collected a dataset based on the routine physical examination, the breaking continuous flash suppression (b-CFS) paradigm, and an attention network test (ANT) in 140 immigrants under the hypoxic Tibetan environment. We combined electroencephalography and multilevel mediation analysis to investigate the relationship between RBC properties and consciousness/attention. The results showed that RBC function, via two independent neurophysiological pathways, not only triggered interoceptive re-representations in the insula and awareness connected to orienting attention but also induced an immune response corresponding to consciousness and executive control. Importantly, consciousness played a fundamental role in executive function which might be associated with the level of perceived stress. These results indicated the important role of oxygen-transport in heart-brain interactions, in which the related stress response affected consciousness and executive control. The findings provide new insights into the neurophysiological schema of heart-brain interactions.

Effect of single hyperbaric oxygen treatment on attention networks in young migrants in Tibet / 生理学报

Many studies have shown that high-altitude exposure could significantly influence human cognition, and the approaches which could enhance the human cognition in high-altitude hypoxia environment attract great attention. In the present study, we recruited a total of 60 subjects who had been migrated to Tibet University as adults for more than one year. These participants were randomly divided into the experimental group and the control group. The participants in the experimental group were instructed to complete a hyperbaric oxygen treatment, and those in the control group just completed a wait condition. By using the attention network test (ANT), the changes of the attention function before and after a single session of hyperbaric oxygen treatment were explored. The results showed that single hyperbaric oxygen treatment significantly improved the orienting function of attention, with an obvious post-intervention effect, but not the alerting and conflict function of attention. We also found a strong association between alerting function and conflict function after the end of intervention, suggesting the change of the overall performance of attention function. The present findings might suggest that the improvement of attention function by a single session of hyperbaric oxygen intervention is derived from the increase of general cognitive resources, rather than the transfer of cognitive resources within the attention system.

Long-term exposure to high altitude affects spatial working memory in migrants-evidence from time and frequency domain analysis / 生理学报

Long-term exposure to high altitude affects spatial working memory. Previous studies have focused on the analysis of electroencephalogram (EEG) components in time domain rather than in frequency domain. To explore the influence of long-term high altitude exposure on time dynamic characteristics and neural oscillation process of the spatial working memory, n-back task combined with the technology of event related potential recording was performed on 20 young migrants who grew at low altitude before the age of 18 and moved to high altitude more than three years ago, and 21 young people who had never been to the high altitude. EEG data were recorded, and the time domain and frequency domain analyses were performed. The results showed that the response time was longer and the accuracy rate was lower under the 2-back condition in the high altitude group compared with those in low altitude group. The late positive potential (LPP) amplitude was more negative, P2 amplitude was more positive in the 2-back condition, and the power value of early delta frequency band (1-4 Hz, 160-300 ms) was larger, while the power values of late delta frequency band (1-4 Hz, 450-650 ms) and theta frequency band (4-8 Hz, 450-650 ms) were smaller in the high altitude group compared with those in low altitude group. The results suggested that long-term exposure to high altitude affected the spatial working memory ability of the migrants, which was reflected in the lack of attention resources in the later matching stage, decreased response inhibition ability and information maintenance ability, and thus resulted in impaired spatial working memory.

The effect of high altitude on human color perception / 生理学报

Exposure to a high altitude hypoxia environment has significant negative effects on human central nervous system. Many previous studies have explored the influence of the high altitude environment on human color perception in a simulated high altitude environment or in an environment acutely exposed to high altitude, but little has been done in migrators and natives exposed to high altitude and low oxygen for a long period of time. In this study, the minimal-change method was used to examine whether the color perception of red, green, blue and yellow was affected by the high altitude in 30 plain residents, 30 Han migrators who have lived in the high altitude for 2 years, and 28 high-altitude-adapted Tibetan natives. The results showed that long-term high altitude exposure had the most significant effect on the blue and red color perception in the natives and the migrators, with the effect on the blue color being significantly greater than that on the red color. However, the effects on green color processing only happened to the natives. The results suggest that there is an internal correlation between blood supply and selectivity changes of visual color processing caused by exposure to the plateau environment.