Exercise in isolation: a countermeasure for electrocortical, mental and cognitive impairments

Introduction: Mental impairments, including deterioration of mood and cognitive performance, are known to occur during isolation and space missions, but have been insufficiently investigated. Appropriate countermeasures are required, such as exercise, which is known to prevent mood disorders for prolonged space and isolation missions. Based on the interaction of brain activity, mood and cognitive performance, this study aims to investigate the effect of long-term isolation and confinement and the long-term effect of exercise on these parameters.\ud \ud Methods: Eight male volunteers were isolated and confined for about eight month during the winter period at the Antarctic Concordia Station. Every six weeks electroencephalographic measurements were recorded under rest conditions, and cognitive tests and a mood questionnaire were executed. Based individual training logs, subjects were afterwards separated into an active (> 2500 arbitrary training units/interval) or inactive (< 2500 arbitrary training units/interval) group.\ud \ud Results: A long-term effect of exercise was observed for brain activity and mood. Regularly active people showed a decreased brain activity (alpha and beta) in the course of isolation, and steady mood. Inactive people instead first increased and than remained at high brain activity accompanied with a deterioration of mood. No effect of exercise and isolation was found for cognitive performance.\ud \ud Conclusion: The findings point out the positive effect of regularly performed voluntary exercise, supporting subjective mental well-being of long-term isolated people. The choice to be regularly active seems to support mental health, which is not only of interest for future isolation and space missions

Altitude and Seasonality Impact on Sleep in Antarctica

BACKGROUND: This study investigates the effects of seasonality and altitude on sleep in extreme Antarctic conditions. METHODS: During summer and winter periods, 24 h of actimetric recordings were obtained at two different research stations, Dumont d'Urville (sea level altitude) and Concordia (corrected altitude 12,467 ft or 3800 m). RESULTS: During daytime, there were no altitude- or season-related differences in time spent at work, energy expenditure, or number of walking steps. During the nighttime however, total sleep time was longer (m = 427.4; SD = 42.4), sleep efficiency higher (m = 90; SD = 4.8), and wake after sleep onset shorter (m = 42.2; SD = 28.7) at sea level. Additionally, sleep fragmentation episodes and energy expenditure were higher during summer than winter periods. DISCUSSION: Our results show that dramatic variations in light exposure are not the only main factor affecting sleep quality in Antarctica, as altitude also markedly impacted sleep in these conditions. The effect of altitude-induced hypoxia should be taken into account in future investigations of sleep in extreme environments.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

EAMI: A qualitative quantification of periodic breathing based on amplitude of oscillations

Study Objectives: Periodic breathing is sleep disordered breathing characterized by instability in the respiratory pattern that exhibits an oscillatory behavior. Periodic breathing is associated with increased mortality, and it is observed in a variety of situations, such as acute hypoxia, chronic heart failure, and damage to respiratory centers. The standard quantification for the diagnosis of sleep related breathing disorders is the apnea-hypopnea index (AHI), which measures the proportion of apneic/hypopneic events during polysomnography. Determining the AHI is labor-intensive and requires the simultaneous recording of airflow and oxygen saturation. In this paper, we propose an automated, simple, and novel methodology for the detection and qualification of periodic breathing: the estimated amplitude modulation index (eAMI). Patients or Participants: Antarctic cohort (3,800 meters): 13 normal individuals. Clinical cohort: 39 different patients suffering from diverse sleep-related pathologies. Measurements and Results: When tested in a population with high levels of periodic breathing (Antarctic cohort), eAMI was closely correlated with AHI (r = 0.95, P < 0.001). When tested in the clinical setting, the proposed method was able to detect portions of the signal in which subclinical periodic breathing was validated by an expert (n = 93; accuracy = 0.85). Average eAMI was also correlated with the loop gain for the combined clinical and Antarctica cohorts (r = 0.58, P < 0.001). Conclusions: In terms of quantification and temporal resolution, the eAMI is able to estimate the strength of periodic breathing and the underlying loop gain at any given time within a record. The impaired prognosis associated with periodic breathing makes its automated detection and early diagnosis of clinical relevance.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

EEG results.

<p>Percentage changes from interval 1 of brain activity within the alpha (left) and beta (right) frequency band for the inactive (grey) and the active (black) group in the course of interval 1 to 7 (x-axis). Displayed are mean values plus/minus standard deviations.</p

Training load and frequency.

<p>Training load (left) and training frequency (right) per interval for the active (black) and inactive (grey) group for intervals 2 to 7 (interval 1 data missing). Displayed are mean values plus/minus standard deviations.</p

Results Cognitive tasks.

<p>Percentage changes from interval 1 of Brain Games Score (mean of the three games) for the inactive (grey) and the active (black) group in the course of interval 1 to 7 (x-axis). Displayed are mean values plus/minus standard deviations.</p