Publications by authors named "Pascal VAN Beers"

Hypoxia (HY) and sleep deprivation have opposite effects on appetite. As HY may alter sleep, it may be informative to assess the accumulative effects of these two stressors on hunger, energy intake (EI), and food reward. Seventeen young, active, healthy males completed four 5-hr sessions in normoxia (NO) or normobaric HY (FIO2 = 13.

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  • Caffeine can help mitigate the negative effects of sleep deprivation, but it may also reduce the quality and duration of recovery sleep.
  • A study with 41 participants showed that after total sleep deprivation (38 hours of staying awake), those who took caffeine had less total sleep time and experienced more disturbances during recovery sleep compared to those who received a placebo.
  • The effects of caffeine on recovery sleep varied depending on participants' regular caffeine consumption, suggesting that advice on caffeine intake may need to be tailored for individuals, especially night-shift workers.
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Introduction: Exposure to moderate levels of simulated hypoxia has subtle cognitive effects relative to ground level, in healthy individuals. However, there are few data on the cognitive consequences of the combination of hypoxia and partial sleep deprivation, which is a classic military or civilian operational context. In this study, we tested the hypothesis that exposure to moderate hypoxia while sleep-restricted impairs several domains of cognition, and we also assessed physiological parameters and salivary concentrations of cortisol and alpha-amylase.

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Aircraft pilots face a high mental workload (MW) under environmental constraints induced by high altitude and sometimes sleep restriction (SR). Our aim was to assess the combined effects of hypoxia and sleep restriction on cognitive and physiological responses to different MW levels using the Multi-Attribute Test Battery (MATB)-II with an additional auditory Oddball-like task. Seventeen healthy subjects were subjected in random order to three 12-min periods of increased MW level (low, medium, and high): sleep restriction (SR, <3 h of total sleep time (TST)) vs.

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  • Caffeine acts as a psychostimulant that can alleviate the negative effects of sleep deprivation, and this study aimed to examine its impact on cognitive performance and brain activity during complete sleep loss, while considering each individual's caffeine habits.* -
  • The study included 37 participants in a double-blind experiment where they underwent total sleep deprivation with either caffeine or placebo; their attention was measured using a test every six hours, alongside EEG monitoring to analyze brain activity.* -
  • Results showed that caffeine improved reaction times compared to the placebo during sleep deprivation; however, individuals with high caffeine consumption exhibited poorer attentional performance, indicating that habitual high caffeine intake may worsen the ability to cope with sleep loss.*
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  • Trauma-related nightmares (TRNs) significantly affect the sleep quality and treatment outcomes of PTSD patients, making it important to study them in realistic home environments rather than sleep labs.
  • The study utilized two ambulatory devices to collect objective sleep data from 60 veterans and active-duty service members, correlating this data with their subjective complaints about sleep and TRNs over five nights.
  • Findings showed a connection between TRNs and sleep stages, revealing that most awakenings from TRNs occurred during NREM sleep, alongside differences in electrodermal activity (EDA) before TRNs, suggesting EDA may serve as a potential marker for these nightmares.
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Heat exposure is thought to reduce energy intake (EI) but studies are sparse and results not always concordant. The aim of this study was to examine whether a 16-h exposure to 32 °C leads to reduced EI compared to a control session (22 °C) and whether modifications in appetite sensations or food reward are implied. Sixteen healthy, lean, and active participants (9 women and 7 men, 25 ± 5 yo, body mass index: 22.

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Introduction: It is widely admitted that both total sleep deprivation (TSD) and extended task engagement (Time-On-Task, TOT) induce a cognitive fatigue state in healthy subjects. Even if EEG theta activity and adenosine both increase with cognitive fatigue, it remains unclear if these modifications are common mechanisms for both sustained attention and executive processes.

Methods: We performed a double-blind counter-balanced (placebo (PCBO) and caffeine (CAF) - 2×2.

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Adding relaxation techniques during nap or auditory stimulation of EEG slow oscillation (SO) during nighttime sleep may limit cognitive impairments in sleep-deprived subjects, potentially through alleviating stress-releasing effects. We compared daytime sleepiness, cognitive performances, and salivary stress biomarker responses in 11 volunteers (aged 18-36) who underwent 5 days of sleep restriction (SR, 3 h per night, with 30 min of daily nap) under three successive conditions: control (SR-CT), relaxation techniques added to daily nap (SR-RT), and auditory stimulation of sleep slow oscillations (SO) during nighttime sleep (SR-NS). Test evaluation was performed at baseline (BASE), the fifth day of chronic SR (SR5), and the third and fifth days after sleep recovery (REC3, REC5, respectively).

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Sleep is known to benefit memory consolidation, but little is known about the contribution of sleep stages within the sleep cycle. The sequential hypothesis proposes that memories are first replayed during nonrapid-eye-movement (NREM or N) sleep and then integrated into existing networks during rapid-eye-movement (REM or R) sleep, two successive critical steps for memory consolidation. However, it lacks experimental evidence as N always precedes R sleep in physiological conditions.

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Several genetic polymorphisms differentiate between healthy individuals who are more cognitively vulnerable or resistant during total sleep deprivation (TSD). Common metrics of cognitive functioning for classifying vulnerable and resilient individuals include the Psychomotor Vigilance Test (PVT), Go/noGo executive inhibition task, and subjective daytime sleepiness. We evaluated the influence of 14 single-nucleotide polymorphisms (SNPs) on cognitive responses during total sleep deprivation (continuous wakefulness for 38 h) in 47 healthy subjects (age 37.

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Study Objectives: Total sleep deprivation is known to have significant detrimental effects on cognitive and socio-emotional functioning. Nonetheless, the mechanisms by which total sleep loss disturbs decision-making in social contexts are poorly understood. Here, we investigated the impact of total sleep deprivation on approach/avoidance decisions when faced with threatening individuals, as well as the potential moderating role of sleep-related mood changes.

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  • Researchers used piezoelectric sensors to monitor sleep patterns in rats, comparing its effectiveness to traditional electroencephalogram (EEG) methods over 7 days.
  • Both methods showed similar results regarding total sleep time, with longer sleep detected under certain lighting conditions, and correlated closely with each other.
  • The piezoelectric system demonstrated a 90% accuracy in distinguishing between non-rapid eye movement and rapid eye movement sleep, making it a promising non-invasive tool for studying sleep and its effects on health.
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  • The study explored how specific genetic variations (SNPs) affect the impact of caffeine on attention and performance during sleep deprivation in 37 participants.
  • It found that carriers of certain SNPs (TNF-α and COMT) were more sensitive to caffeine's effects, but this did not improve their performance despite increased degradation from sleep loss.
  • Additionally, genetic factors influenced EEG activity related to sleep deprivation, highlighting that caffeine can partially mitigate neurobehavioral impairments linked to sleep loss.
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Introduction: This study aimed to explore the relationship between elite rugby union match and postmatch sleep architecture and to investigate the effects of a high-heat capacity mattress (MAT) and a whole-body cryotherapy (WBC) session on postmatch sleep architecture.

Methods: Nineteen elite male U23 rugby union players performed in three official matches, followed by three experimental conditions, in a randomized order: MAT, WBC, and no intervention (CONT). Match load was evaluated using GPS trackers and video analyses.

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Study Objectives: The development of ambulatory technologies capable of monitoring brain activity during sleep longitudinally is critical for advancing sleep science. The aim of this study was to assess the signal acquisition and the performance of the automatic sleep staging algorithms of a reduced-montage dry-electroencephalographic (EEG) device (Dreem headband, DH) compared to the gold-standard polysomnography (PSG) scored by five sleep experts.

Methods: A total of 25 subjects who completed an overnight sleep study at a sleep center while wearing both a PSG and the DH simultaneously have been included in the analysis.

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Sleep debt is becoming a better acknowledged cause of physiological stress and neurobehavioral deficits with major public-health concerns. We investigated whether exposure to blue light during daytime could be an efficient countermeasure to limit sleep restriction's impact on relevant behavioral (stress, sleepiness, sustained attention, and memory performance) and physiological (saliva cortisol, testosterone, and alpha-amylase) markers. Our semi-ecological, crossover, randomized design included 17 young men that underwent two sleep-restricted nights (3 h each) followed or not by blue light exposure (30-min-long sessions at 100 lux repeated four times throughout the day).

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Objective: Exercise training has been shown to improve learning and memory, and to protect against the negative impact of sleep deprivation. The aim of this study was to investigate the effects of seven weeks of moderate- and high-intensity interval exercise training on vigilance/sustained attention, inhibition processes and working memory during 40-h total sleep deprivation (TSD) in 16 healthy young men.

Methods: The subjects were evaluated before (Baseline, BAS) and during TSD, and the day after a night of recovery sleep (Recovery, REC).

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Sleep extension has been associated with better alertness and sustained attention capacities before, during and after sleep loss. However, less is known about such beneficial effect on executive functions (EFs). Our aim was to investigate such effects on two EFs (i.

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We investigated the consequences of sleep restriction (SR) on maintenance of wakefulness capacities and diurnal sleepiness through microsleeps monitoring. 12 healthy males (20-36 years old) were sleep restricted (4 h per night) during 7 nights followed by 13 nights of recovery sleep. Participants completed Karolinska Sleepiness Scale (KSS) and Maintenance of Wakefulness Test (MWT) at baseline (B), during SR (SR1, SR4 and SR7) and during recovery (R3 and R13), while continuously recorded for EEG analysis.

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Background: Sleep loss is a risk factor for cardiovascular events mediated through endothelial dysfunction.

Aims: To determine if 7weeks of exercise training can limit cardiovascular dysfunction induced by total sleep deprivation (TSD) in healthy young men.

Methods: 16 subjects were examined during 40-h TSD, both before and after 7weeks of interval exercise training.

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Chronic sleep restriction (CSR) induces neurobehavioral deficits in young and healthy people with a morning failure of sustained attention process. Testing both the kinetic of failure and recovery of different cognitive processes (i.e.

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Objectives: To investigate the effects of 6 nights of sleep extension on sustained attention and sleep pressure before and during total sleep deprivation and after a subsequent recovery sleep.

Design: Subjects participated in two experimental conditions (randomized cross-over design): extended sleep (EXT, 9.8 ± 0.

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Background: To assess the effects of isolation, inadequate exposure to light and specific shift work on the subjective and objective measurements of sleep and alertness of submariners.

Purpose: A strictly controlled randomized crossover study with the polysomnography recorded twice during the mission.

Methods: Setting: Shift and night work with prolonged (70 days) social isolation from the real world (with no phone or Internet contact with families or friends during a routine mission aboard the "Téméraire" French Strategic Submarine with Ballistic Nuclear missiles (SSBN).

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