The effect of highly concentrated oxygen administration on cerebral activation levels and lateralization in visuospatial tasks

The effect of acute normobaric hyperoxia on cognition: a systematic review, meta-analysis and meta-regression

This systematic review, meta-analysis and meta-regression examined the effect of acute normobaric hyperoxia breathing on cognition in healthy humans. 23 studies were included providing 76 effect estimates (EE). Hyperoxic breathing improved memory accuracy (22 EEs; g = 0.34) and speed (9 EEs; g = 0.59), attention accuracy (7 EEs; g = 0.59) and speed (7 EEs; g = 0.51), reaction speed (8 EEs; g = 0.82), crystallised intelligence (7 EEs; g = 0.73), executive function (6 EEs; g = 0.88) and information processing (10 EEs; g = 0.62). However, the overall quality of evidence was low (average Rosendal score of 47%) and there was a large range of study heterogeneity, with prediction intervals often crossing 0; therefore, reducing the reliability of the magnitude of these favourable effects. Oxygen percentage, 100% compared with 22-99% oxygen, temporal position of administration to task performance, and study quality did not influence the overall weighted mean effects for most cognitive domains. Altogether, despite beneficial results, further high quality research is required prior to recommending hyperoxic breathing to enhance cognition.

Human physiological responses to wooden indoor environment

Previous studies are mainly focused on non-wooden environments, whereas few are concerned with wooden ones. How wooden indoor environments impact the physiology of the occupants is still unclear. The purpose of this study was to explore the distinct physiological responses to wooden and non-wooden indoor environments, assessed by physiological parameters tests including blood pressure, electrocardiogram measurements, electro-dermal activity, oxyhemoglobin saturation, skin temperature, and near distance vision. Twenty healthy adults participated in this experiment, and their physiological responses were evaluated in a 90minute investigation. The results illustrated that; less tension and fatigue were generated in the wooden rooms than in the non-wooden rooms when the participants did their work. In addition, the study also found that the wooden environments benefit the autonomic nervous system, respiratory system, and visual system. Moreover, wooden rooms play a valuable role in physiological regulation and ease function especially after a consecutive period of work. These results provide an experimental basis to support that wooden environment is beneficial to indoor occupants than the non-wooden indoor environment.

Monitoring of autonomic response to sociocognitive tasks during treatment in children with Autism Spectrum Disorders by wearable technologies: A feasibility study

BACKGROUND

Autism Spectrum Disorders (ASD) represent a heterogeneous set of neurodevelopmental disorders characterized by impairments in social domain, where the autonomic nervous system (ANS) plays an important role. Several researchers have studied the ANS in ASD, during specific cognitive or sensory stimuli while few studies have examined response during social interactions. Wearable technologies can be very helpful in monitoring autonomic response in children with ASD in semi-naturalistic setting. The novelty of this study is to use such technologies to acquire physiological signals during therapeutic sessions supported by interactive "serious games" and to correlate the ANS response to the engagement of the child during sociocognitive tasks for an evaluation of the treatment effect and for the personalization of the therapy.

METHOD

A wearable chest belt for electrocardiographic (ECG) signal recording was used and specific algorithms for the extraction of clinically relevant features (Heart Rate - HR, Root Mean Square of the Successive Differences - RMSSD and Respiratory Sinus Arrhythmia - RSA) were developed. Sociocognitive tasks were mediated by "serious games" implemented on two tablets, which allowed a precise coding of the behaviors of the children. A longitudinal assessment of the physiological response of the children during six months of treatment was performed.

RESULTS

A link between physiological response, i.e. decrease in RMSSD and RSA, and engagement of the children during sociocognitive tasks was found. Longitudinal changes in the children's autonomic response, including a decrease of RSA during the engagement throughout the therapeutic sessions, were found.

CONCLUSIONS

These results foster the feasibility of this methodology to be applied in a clinical setting for the monitoring of the ANS response of children with ASD during treatment. A larger sample of patients is needed to confirm these preliminary findings.

Changes in memory performance, heart rate, and blood oxygen saturation due to 30% oxygen administration

This study investigated the effect of 30% oxygen administration on memory cognitive performance, blood oxygen saturation, and heart rate. Ten healthy male and female college students (male: 25.8+/-0.8 years, female: 24.2+/-1.9 years) participated in the study. The results of the memory performance analysis reveal that word recall rates were enhanced with 30% oxygen administration compared to 21% oxygen. When 30% oxygen was supplied, blood oxygen saturation was increased and heart rate was decreased compared to that with 21% oxygen administration. Significant positive correlations were found between changes in oxygen saturation and heart rate and memory performance. This result supports the hypothesis that 30% oxygen administration would lead to increases in memory performance.

Physiological mechanism underlying the improvement in visuospatial performance due to 30% oxygen inhalation

This study investigated the effect of 30% oxygen inhalation on visuospatial cognitive performance, blood oxygen saturation, and heart rate. Six male (25.8(mean)+/-1.0(SD) years) and six female (23.8+/-1.9 years) college students participated in this experiment. Two psychological tests were developed to measure the performance level of visuospatial cognition. The experiment consisted of two runs: one was a visuospatial cognition task under normal air (21% oxygen) condition and the other under hyperoxic air (30% oxygen) condition. The experimental sequence in each run consisted of four phases, that were Rest1 (1min), Control (1min), Task (4min), and Rest2 (4min). Blood oxygen saturation and heart rate were measured throughout the course of four phases. The analysis of behavioral performance with 30% oxygen administration when compared to 21% oxygen revealed that the mean performance was improved. When supplied 30% oxygen in the air, the blood oxygen saturation was increased while the heart rate was decreased compared to those under 21% oxygen condition. We conclude that 30% oxygen inhalation enhanced visuospatial performance by the increased the oxygen saturation in the blood.

Cognitive function in outbred house mice after 22 weeks of drinking oxygenated water

Oxygen-enriched drinking water, which is increasingly sold worldwide, is claimed to "keep both the body and the mind healthy." However, currently there is no scientific evidence for such a statement. Therefore, we assessed the effect of 22 weeks of drinking oxygenated water on cognitive performance in healthy mice, using a spatial learning task and behavioral observations. Thirty-six female mice (age 3 to 6 months) received either hyperoxic or normal tap water (approximately 6.6 vs. 1.8 microg O(2) g(-1) day(-1), respectively) throughout the study period. Mice were weighed one to two times per month, and a blood sample was taken from the tail to determine the hematocrit. In addition, red blood cells were counted microscopically one and two months after the start of the experiment. Four weeks after the last blood sample (21 weeks after the start of the experiment), exploration behavior and locomotor activity were observed on a holeboard, and learning ability tests were performed using an elevated open maze. No significant differences were seen between groups for any of the parameters investigated. Thus, the study does not support the hypothesis that drinking oxygenated water improves cognitive function or hematological parameters in mice.

Effect of 30% Oxygen Administration on Verbal Cognitive Performance, Blood Oxygen Saturation and Heart Rate

This study investigated the effect of 30% oxygen administration on verbal cognitive performance, blood oxygen saturation, and heart rate. Five male (24.6(+/-0.9) years) and five female (22.2(+/-1.9) years) college students were selected as the subjects for this study. Two psychological tests were developed to measure the performance level of verbal cognition. The experiment consisted of two runs: one was a verbal cognition task, with normal air (21% oxygen) administered and the other was with hyperoxic air (30% oxygen) administered. The experimental sequence in each run consisted of Rest 1 (1 min), Control (1 min), Task (4 min), and Rest 2 (4 min). Blood oxygen saturation and heart rate were measured throughout the four phases. The results of the verbal behavioural analysis reveal that accuracy rates were enhanced with 30% oxygen administration compared to 21% oxygen. When 30% oxygen was supplied, blood oxygen saturation was increased significantly compared to that with 21% oxygen administration, whereas heart rate showed no significant difference. Significant positive correlations were found between changes in oxygen saturation and cognitive performance. This result supports the hypothesis that 30% oxygen administration would lead to increases in verbal cognitive performance.