arnaud rabat - Academia.edu (original) (raw)

Papers by arnaud rabat

Sleep, 2020

Introduction Mental Fatigue is commonly questioned regarding time on task or sleep debt effect (H... more Introduction Mental Fatigue is commonly questioned regarding time on task or sleep debt effect (Hockey, 2013; Pattyn et al., 2018) or sleep debt effect (Krause et al., 2017). No studies have neither investigated contributions of these two factors for different cognitive processes nor benefit of caffeine. Methods 24 right-handed and healthy subjects (18–50 years old), with a median chronotype and sleep need participated in a 2-experimental counter-balanced (placebo: PBO and caffeine: COFFEE - 2.5 mg/kg) total sleep deprivation protocol (TSD = 27 hours of continuous wakefulness). Subjective sleepiness (KSS), sustained attention (PC-PVT), inhibition (Go-NoGo) and working memory (2N-Back) capabilities were tested each morning during BASE and TSD (10 min. test session from 9:15 am to 10:15 am). Caffeine was ingested with a decaffeinated drink at 8:30 am. Results KSS score (5.6±0.4 vs 3.2±0.3; p<0.001), number of Lapses (9.8±1.7 vs 0.4±0.2; p<0.001), mean response time (RT: 308±4.9 ...

Nature and Science of Sleep, 2022

It is widely admitted that both total sleep deprivation (TSD) and extended task engagement (Time-... more 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 counterbalanced (placebo (PCBO) and caffeine (CAF)-2×2.5 mg/kg/24 h)) study on 24 healthy subjects (33.7 ± 5.9 y). Subjects participated in an experimental protocol including an habituation/training day followed by a baseline day (D0 and D1) and a total sleep deprivation (TSD) day beginning on D1 at 23:00 until D2 at 21:00. Subjects performed the psychomotor vigilance test (PVT) assessing sustained attention, followed by the executive Go-NoGo inhibition task and the 2-NBack working memory task at 09:15 on D1 and D2. Results: We showed differential contributions of TSD and TOT on deficits in sustained attention and both executive processes. An alleviating effect of caffeine intake is only observed on sustained attention deficits related to TSD and not at all on TOT effect. The caffeine dose slows down the triggering of sustained attention deficits related to TOT effect. Discussion: These results suggest that sustained attention deficits induced by TSD rely on the adenosinergic mechanism whereas TOT effect observed for both sustained attention and executive would not.

Brain Sciences, 2022

Adding relaxation techniques during nap or auditory stimulation of EEG slow oscillation (SO) duri... more 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). At SR5, less degradation was observed for percentage of commission errors in the executive Go–noGo inhibition task in SR-RT condition compared to SR-CT, and for sleepiness score in SR-NS conditio...

Journal of Science and Medicine in Sport, 2017

The aim of the study was to collect data about the physical performances of the Dendra panoply we... more The aim of the study was to collect data about the physical performances of the Dendra panoply wearers during simulated Trojan war combat fighting. Methods: All the participants were members of the elite forces of the Greek army (n = 20) who volunteered for the research having some specific anthropometric characteristics. They were wearing an exact copy of the panoply made by archeologists and were

BIO-PROTOCOL, 2020

Decision-making is a complex cognitive process which consists of choosing one option among severa... more Decision-making is a complex cognitive process which consists of choosing one option among several alternatives. In humans, this process is featured in the Iowa gambling task (IGT), a decision-making task that mimics real life situations by reproducing uncertain conditions based on probabilistic rewards or penalties (see Background). Several authors wanted to adapt the IGT in rodents with subtle differences in protocols that match various aspects of the human task. Here we propose, for the first time in mice, a protocol that contains the most important characteristics of the IGT: 4 different options, choices based on 4 ambiguous outcomes with immediate and long term rewards, a total of 100 trials, no learning of the contingency before the task, and presence of both a certain reward and a probable penalty. During this task, mice have to choose between options more or less advantageous in the short and long term by developing a decision-making strategy that differs between individuals. Therefore, the strength of this protocol is that it is one of the first to enable the study of decision-making in a complex situation, and demonstrates inter-individual differences regarding decision-making strategies in mice.

Genes, 2021

This study investigated whether four single nucleotide polymorphisms (SNPs) moderated caffeine ef... more This study investigated whether four single nucleotide polymorphisms (SNPs) moderated caffeine effects on vigilance and performance in a double-blind and crossover total sleep deprivation (TSD) protocol in 37 subjects. In caffeine (2 × 2.5 mg/kg/24 h) or placebo-controlled condition, subjects performed a psychomotor vigilance test (PVT) and reported sleepiness every six hours (Karolinska sleepiness scale (KSS)) during TSD. EEG was also analyzed during the 09:15 PVT. Carriers of the TNF-α SNP A allele appear to be more sensitive than homozygote G/G genotype to an attenuating effect of caffeine on PVT lapses during sleep deprivation only because they seem more degraded, but they do not perform better as a result. The A allele carriers of COMT were also more degraded and sensitive to caffeine than G/G genotype after 20 h of sleep deprivation, but not after 26 and 32 h. Regarding PVT reaction time, ADORA2A influences the TSD effect but not caffeine, and PER3 modulates only the caffeine ...

Médecine du Sommeil, 2020

Objectif La fatigue cognitive est souvent abordee sous l’angle du temps passee a la tâche (TPT) o... more Objectif La fatigue cognitive est souvent abordee sous l’angle du temps passee a la tâche (TPT) ou d’une privation totale de sommeil (PTS) mais jamais avec les deux facteurs en meme temps. De meme, l’efficacite de la cafeine n’a jamais ete evaluee avec cette double contrainte PTS et TPT. Methodes 24 sujets droitiers (18–50 ans), de chronotype intermediaire, ont rempli/realise pendant 1 heure (9h15–10h15), avant et apres une PTS (27 heures d’eveil), un KSS, un PVT (attention soutenue), un Go-NoGo (inhibition) et un 2N-Back (memoire de travail). 2,5 mg/kg de cafeine ou un placebo ont ete ingere (en aveugle) chaque matin a 8h30. Resultats La PTS augmente la somnolence (5,6 ± 0,4 vs 3,2 ± 0,3 ; p Conclusion Ces resultats, coherents avec des precedents, montrent une cinetique differentielle de la fatigue cognitive (PTS et TPT) pour l’attention soutenue et deux processus executifs et des benefices partiels du cafe, relancant l’idee de substrats neurobiologiques differents.

Socio-professional pressures push people to sleep less which leads to chronic sleep debt (CSD) fo... more Socio-professional pressures push people to sleep less which leads to chronic sleep debt (CSD) for a significant percentage of the population. Although the health consequences of CSD are well known, research shows that high-level cognitive processes in humans are more affected by acute sleep debt (ASD) rather than CSD (Drake et al., 2001). We have previously shown that ASD has deleterious effects on decision-making in mice and that some mice were more sensitive to ASD than others (Pittaras et al., 2018) by using a rodent version of the Iowa Gambling Task (Bechara et al., 1994). In this study, we showed that, as in humans, CSD has fewer effects on decision-making compared to ASD. We hypothesize that this observation was due to the set-up of a compensatory mechanism.

Frontiers in Neuroscience, 2019

Introduction: Sleep extension has been associated with better alertness and sustained attention c... more Introduction: 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.e., inhibition and working memory) for subjects submitted to total sleep deprivation and one-night of recovery. Methods: Fourteen healthy men (26-37 years old) participated in an experimental cross-over design with two conditions: extended sleep (EXT, 9.8 ± 0.1 h of Time In Bed, TIB) and habitual sleep (HAB, 8.2 ± 0.1 h TIB). During these two conditions subjects underwent two consecutive phases: Six nights of either EXT or HAB followed by 3 days in-laboratory: baseline (BASE), TSD (38 h) and after recovery (REC). EFs capacities were assessed through Go-NoGo (inhibition) and 2N-Back (working memory) tasks. Both EFs capacities were measured at different time (BASE/TSD/REC:

Sleep medicine reviews, Jan 5, 2018

In recent decades, increasing evidence has positioned slow-wave sleep (SWS) as a major actor in n... more In recent decades, increasing evidence has positioned slow-wave sleep (SWS) as a major actor in neurophysiological phenomena such as glucose metabolism, hormone release, immunity and memory. This proposed role for SWS, coupled with observations of impaired SWS in several pathologies as well as in aging, has led some researchers to implement methods that could specifically enhance SWS. This review aims to gather the current knowledge extending from the cell to the clinic, in order to construct an overview of what is currently known about so-called SWS. We slowly expand the view from the molecular processes underlying SWS to the cell unit and assembly to cortical manifestations. We then describe its role in physiology and cognition to finally assess its association with clinical aspects. Finally, we address practical considerations for several techniques that could be used to manipulate SWS, in order to improve our understanding of SWS and possibly help the development of treatments f...

Consciousness and cognition, 2018

We investigated the consequences of sleep restriction (SR) on maintenance of wakefulness capaciti... more 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. During SR, MWT latencies decreased (SR7: -24.4%), whereas the number, the cumulative duration of microsleeps and KSS scores increased. Recovery nights allowed MWT latencies, KSS scores and all sleep values to return to baseline levels, while a rebound in N3, N3% and REM% sleep stages occurred. During SR, the maintenance of N3 sleep duration seems not sufficient to reduce daytime sleepiness and MWT results did not reflect the sleepiness levels characterized by persistent sleep attacks.

Médecine du Sommeil, 2017

s sous-jacents. L'objectif à long terme est d'anticiper et améliorer la prise en charge des compl... more s sous-jacents. L'objectif à long terme est d'anticiper et améliorer la prise en charge des complications associées au SAOS.

International journal of cardiology, 2017

Sleep loss is a risk factor for cardiovascular events mediated through endothelial dysfunction. T... more Sleep loss is a risk factor for cardiovascular events mediated through endothelial dysfunction. To determine if 7weeks of exercise training can limit cardiovascular dysfunction induced by total sleep deprivation (TSD) in healthy young men. 16 subjects were examined during 40-h TSD, both before and after 7weeks of interval exercise training. Vasodilatation induced by ACh, insulin and heat (42°C) and pulse wave velocity (PWV), blood pressure and heart rate (HR) were assessed before TSD (controlday), during TSD, and after one night of sleep recovery. Biomarkers of endothelial activation, inflammation, and hormones were measured from morning blood samples. Before training, ACh-, insulin- and heat-induced vasodilatations were significantly decreased during TSD and recovery as compared with the control day, with no difference after training. Training prevented the decrease of ACh-induced vasodilation related to TSD after sleep recovery, as well as the PWV increase after TSD. A global lowe...

Frontiers in Psychiatry, 2016

Decision-making is an essential component of our everyday life commonly disabled in a myriad of p... more Decision-making is an essential component of our everyday life commonly disabled in a myriad of psychiatric conditions, such as bipolar and impulsive control disorders, addiction and pathological gambling, or schizophrenia. A large cerebral network encompassing the prefrontal cortex, the amygdala, and the nucleus accumbens is activated for efficient decision-making. Methods: We developed a mouse gambling task well suited to investigate the influence of uncertainty and risk in decision-making and the role of neurobiological circuits and their monoaminergic inputs. Neuronal nicotinic acetylcholine receptors (nAChRs) of the PFC are important for decision-making processes but their presumed roles in risk-taking and uncertainty management, as well as in cellular balance of excitation and inhibition (E/I) need to be investigated. results: Using mice lacking nAChRs-β2 −/− mice, we evidence for the first time the crucial role of nAChRs in the fine tuning of prefrontal E/I balance together with the PFC, insular, and hippocampal alterations in gambling behavior likely due to sensitivity to penalties and flexibility alterations. Risky behaviors and perseveration in extinction task were largely increased in β2 −/− mice as compared to control mice, suggesting the important role of nAChRs in the ability to make appropriate choices adapted to the outcome.

Brain Structure and Function, 2016

One of the hallmarks of decision-making processes is the inter-individual variability between hea... more One of the hallmarks of decision-making processes is the inter-individual variability between healthy subjects. These behavioral patterns could constitute risk factors for the development of psychiatric disorders. Therefore, finding predictive markers of safe or risky decision-making is an important challenge for psychiatry research. We set up a mouse gambling task (MGT)adapted from the human Iowa gambling task with uncertain contingencies between response and outcome that furthermore enables the emergence of inter-individual differences. Mice (n = 54) were further individually characterized for locomotive, emotional and cognitive behavior. Individual basal rates of monoamines and brain activation after the MGT were assessed in brain regions related to reward, emotion or cognition. In a large healthy mice population, 44 % showed a balanced strategy with limited risk-taking and flexible choices, 29 % showed a safe but rigid strategy, while 27 % adopted risky behavior. Risky mice took also more risks in other apparatus behavioral devices and were less sensitive to reward. No difference existed between groups regarding anxiety, working memory, locomotion and impulsivity. Safe/rigid mice exhibited a hypoactivation of prefrontal subareas, a high level of serotonin in the orbitofrontal cortex combined with a low level of dopamine in the putamen that predicted the emergence of rigid behavior. By contrast, high levels of dopamine, serotonin and noradrenalin in the hippocampus predicted the emergence of more exploratory and risky behaviors. The coping of C57bl/6J mice in MGT enables the determination of extreme patterns of choices either safe/rigid or risky/flexible, related to specific neurochemical and behavioral markers. Keywords Decision-making Á Inter-individual differences Á Neurobiological markers Á Prefrontal Á Cortex Á Dopamine Á Serotonin Á Noradrenaline Á Flexibility Á Safe behavior Á Risk-taking A. Rabat and S. Granon have equally contributed to the study.

Sleep Medicine, 2015

ABSTRACT INTRODUCTION: Chronic partial sleep deprivation for watchkeepers induces many ill‐fated ... more ABSTRACT INTRODUCTION: Chronic partial sleep deprivation for watchkeepers induces many ill‐fated effects such as sleep fragmentation which provoke significant daytime sleepiness, risk of accident. The knowledge of the time necessary for recovering from such sleep deprivation is important. The aim of this work is to provide an assessment of such time recovering. MATERIALS AND METHODS: Thirty‐two healthy subjects (mariners on warships: 8 women and 24 men) aged 19 to 50 years underwent the same chronic partial sleep deprivation due to watchkeeping during the same test period. A baseline polysomnography (PSG) was performed for all subjects and their latency to sleep [Multiple Sleep Latency Test (MSLT) scores] was evaluated just before the beginning of the test at Di while their follow‐up (PSG) and (MSLT) was done with a certain delay after the end of the test at Df. Main indicators of sleep fragmentation such as the sleep fragmentation index and the sleep diversity index were then computed. RESULTS: The diagnosis of sleep fragmentation produced by clinicians confirms that mariners’ sleep is much fragmented after their mission on the warship relative to the reference night. Comparison of different criteria for the PSG, the MSLT and the indicators of fragmentation index (sleep fragmentation index, sleep diversity index and stage N1 latency) can show that the time required to recover from the partial chronic sleep deprivation is three days for sleep architecture and five days for sleep fragmentation. CONCLUSION: These results have to be compared to an assessment of the cognitive performance. Then we may introduce a minimum rest period during missions in order to increase alertness and responsiveness of the sailors. ACKNOWLEDGEMENTS: We thank the members of the Centre Hospitalier Intercommunal Toulon La Seyne, Sainte Musse Hospital for their contribution to this project particularly the staff of the sleep laboratory and Jean‐Philippe Suppini, head of the Clinical Research Unit.

Sleep, Jan 13, 2015

To investigate the effects of 6 nights of sleep extension on sustained attention and sleep pressu... more 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. Subjects participated in two experimental conditions (randomized cross-over design): extended sleep (EXT, 9.8±0.1 h (mean±SE) time in bed) and habitual sleep (HAB, 8.2±0.1 h time in bed). In each condition, subjects performed two consecutive phases: (1) 6 nights of either EXT or HAB (2) three days in-laboratory: baseline, total sleep deprivation and after 10 h of recovery sleep. Residential sleep extension and sleep performance laboratory (continuous polysomnographic recording). 14 healthy men (age range: 26-37 years). EXT vs. HAB sleep durations prior to total sleep deprivation. Total sleep time and duration of all sleep stages during the 6 nights were significantly higher in EXT than HAB. EXT improved psychomotor vigilance task performance (PVT, both fewer lapses and faster speed) and reduced sleep pres...

Journal of Addiction Research & Therapy, 2013

Understanding the mechanisms underlying decision-making could thus be a key to find successful tr... more Understanding the mechanisms underlying decision-making could thus be a key to find successful treatments of neurological or psychiatric disorders, but also to study healthy subjects at risk. Moreover, the recent, and worldwide, legal opportunity for people to gamble on the web increases dramatically the risk for pathological gambling in the human population [14].