Night Of Total Sleep Deprivation Research Articles

Brain vital sign monitoring of sleep deprivation detects situational cognitive impairment.

Objective, rapid evaluation of cognitive function is critical for identifying situational impairment due to sleep deprivation. The present study used brain vital sign monitoring to evaluate acute changes in cognitive function for healthy adults. Thirty (30) participants were scanned using portable electroencephalography before and after either a night of regular sleep or a night of total sleep deprivation. Brain vital signs were extracted from three established event-related potential components: (1) the N100 (Auditory sensation); (2) the P300 (Basic attention); and (3) the N400 (Cognitive processing) for all time points. As predicted, the P300 amplitude was significantly reduced in the sleep deprivation group. The findings indicate that it is possible to detect situational cognitive impairment due to sleep deprivation using objective, rapid brain vital sign monitoring.

Effects of total sleep deprivation on performance in a manual spacecraft docking task

Sleep deprivation and circadian rhythm disruptions are highly prevalent in shift workers, and also among astronauts. Resulting sleepiness can reduce cognitive performance, lead to catastrophic occupational events, and jeopardize space missions. We investigated whether 24 hours of total sleep deprivation would affect performance not only in the Psychomotor Vigilance Task (PVT), but also in a complex operational task, i.e. simulated manual spacecraft docking. Sixty-two healthy participants completed the manual docking simulation 6df and the PVT once after a night of total sleep deprivation and once after eight hours of scheduled sleep in a counterbalanced order. We assessed the impact of sleep deprivation on docking as well as PVT performance and investigated if sustained attention is an essential component of operational performance after sleep loss. The results showed that docking accuracy decreased significantly after sleep deprivation in comparison to the control condition, but only at difficult task levels. PVT performance deteriorated under sleep deprivation. Participants with larger impairments in PVT response speed after sleep deprivation also showed larger impairments in docking accuracy. In conclusion, sleep deprivation led to impaired 6df performance, which was partly explained by impairments in sustained attention. Elevated motivation levels due to the novelty and attractiveness of the task may have helped participants to compensate for the effects of sleepiness at easier task levels. Continued testing of manual docking skills could be a useful tool both to detect sleep loss-related impairments and assess astronauts’ readiness for duty during long-duration missions.

The effects of sleep deprivation, acute hypoxia, and exercise on cognitive performance: A multi-experiment combined stressors study

IntroductionBoth sleep deprivation and hypoxia have been shown to impair executive function. Conversely, moderate intensity exercise is known to improve executive function. In a multi-experiment study, we tested the hypotheses that moderate intensity exercise would ameliorate any decline in executive function after i) three consecutive nights of partial sleep deprivation (PSD) (Experiment 1) and ii) the isolated and combined effects of a single night of total sleep deprivation (TSD) and acute hypoxia (Experiment 2). MethodsUsing a rigorous randomised controlled crossover design, 12 healthy participants volunteered in each experiment (24 total, 5 females). In both experiments seven executive function tasks (2-choice reaction time, logical relations, manikin, mathematical processing, 1-back, 2-back, 3-back) were completed at rest and during 20 min semi-recumbent, moderate intensity cycling. Tasks were completed in the following conditions: before and after three consecutive nights of PSD and habitual sleep (Experiment 1) and in normoxia and acute hypoxia (FIO2 = 0.12) following one night of habitual sleep and one night of TSD (Experiment 2). ResultsAlthough the effects of three nights of PSD on executive functions were inconsistent, one night of TSD (regardless of hypoxic status) reduced executive functions. Significantly, regardless of sleep or hypoxic status, executive functions are improved during an acute bout of moderate intensity exercise. ConclusionThese novel data indicate that moderate intensity exercise improves executive function performance after both PSD and TSD, regardless of hypoxic status. The key determinants and/or mechanism(s) responsible for this improvement still need to be elucidated. Future work should seek to identify these mechanisms and translate these significant findings into occupational and skilled performance settings.

Microstructural dynamics of motor learning and sleep-dependent consolidation: A diffusion imaging study

Memory consolidation can benefit from post-learning sleep, eventually leading to long-term microstructural brain modifications to accommodate new memory representations. Non-invasive diffusion-weighted magnetic resonance imaging (DWI) allows the observation of (micro)structural brain remodeling after time-limited motor learning. Here, we combine conventional diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) that allows modeling dendritic and axonal complexity in gray matter to investigate with improved specificity the microstructural brain mechanisms underlying time- and sleep-dependent motor memory consolidation dynamics. Sixty-one young healthy adults underwent four DWI sessions, two sequential motor trainings, and a night of total sleep deprivation or regular sleep distributed over five days. We observed rapid-motor-learning-related remodeling in occipitoparietal, temporal, and motor-related subcortical regions, reflecting temporary dynamics in learning-related neuronal brain plasticity processes. Sleep-related consolidation seems not to exert a detectable impact on diffusion parameters, at least on the timescale of a few days.

Sleep deprivation attenuates neural responses to outcomes from risky decision-making.

Sleep loss impacts a broad range of brain and cognitive functions. However, how sleep deprivation affects risky decision-making remains inconclusive. This study used functional MRI to examine the impact of one night of total sleep deprivation (TSD) on risky decision-making behavior and the underlying brain responses in healthy adults. In this study, we analyzed data from N = 56 participants in a strictly controlled 5-day and 4-night in-laboratory study using a modified Balloon Analogue Risk Task. Participants completed two scan sessions in counter-balanced order, including one scan during rested wakefulness (RW) and another scan after one night of TSD. Results showed no differences in participants' risk-taking propensity and risk-induced activation between RW and TSD. However, participants showed significantly reduced neural activity in the anterior cingulate cortex and bilateral insula for loss outcomes, and in bilateral putamen for win outcomes during TSD compared with RW. Moreover, risk-induced activation in the insula negatively correlated with participants' risk-taking propensity during RW, while no such correlations were observed after TSD. These findings suggest that sleep loss may impact risky decision-making by attenuating neural responses to decision outcomes and impairing brain-behavior associations.

Physiological synchrony in electrodermal activity predicts decreased vigilant attention induced by sleep deprivation.

When multiple individuals are presented with narrative movie or audio clips, their electrodermal activity (EDA) and heart rate show significant similarities. Higher levels of such inter-subject physiological synchrony are related with higher levels of attention toward the narrative, as for instance expressed by more correctly answered questions about the narrative. We here investigate whether physiological synchrony in EDA and heart rate during watching of movie clips predicts performance on a subsequent vigilant attention task among participants exposed to a night of total sleep deprivation. We recorded EDA and heart rate of 54 participants during a night of total sleep deprivation. Every hour from 22:00 to 07:00 participants watched a 10-min movie clip during which we computed inter-subject physiological synchrony. Afterwards, they answered questions about the movie and performed the psychomotor vigilance task (PVT) to capture attentional performance. We replicated findings that inter-subject correlations in EDA and heart rate predicted the number of correct answers on questions about the movie clips. Furthermore, we found that inter-subject correlations in EDA, but not in heart rate, predicted PVT performance. Individuals' mean EDA and heart rate also predicted their PVT performance. For EDA, inter-subject correlations explained more variance of PVT performance than individuals' mean EDA. Together, these findings confirm the association between physiological synchrony and attention. Physiological synchrony in EDA does not only capture the attentional processing during the time that it is determined, but also proves valuable for capturing more general changes in the attentional state of monitored individuals.

Enhanced amygdala–cingulate connectivity associates with better mood in both healthy and depressive individuals after sleep deprivation

Sleep loss robustly disrupts mood and emotion regulation in healthy individuals but can have a transient antidepressant effect in a subset of patients with depression. The neural mechanisms underlying this paradoxical effect remain unclear. Previous studies suggest that the amygdala and dorsal nexus (DN) play key roles in depressive mood regulation. Here, we used functional MRI to examine associations between amygdala- and DN-related resting-state connectivity alterations and mood changes after one night of total sleep deprivation (TSD) in both healthy adults and patients with major depressive disorder using strictly controlled in-laboratory studies. Behavioral data showed that TSD increased negative mood in healthy participants but reduced depressive symptoms in 43% of patients. Imaging data showed that TSD enhanced both amygdala- and DN-related connectivity in healthy participants. Moreover, enhanced amygdala connectivity to the anterior cingulate cortex (ACC) after TSD associated with better mood in healthy participants and antidepressant effects in depressed patients. These findings support the key role of the amygdala-cingulate circuit in mood regulation in both healthy and depressed populations and suggest that rapid antidepressant treatment may target the enhancement of amygdala-ACC connectivity.

0217 Trait-Like Stability of Cardiovascular Measures Across Long-Duration Intervals after Baseline and Recovery Sleep Phases

Abstract Introduction We determined for the first time whether individual differences in cardiovascular (CV) measures are observed after repeated baseline and recovery sleep (prior to and after exposure to total sleep deprivation) as well as the stability of such responses across 4-month and 8-month long-duration studies. Methods We conducted a five-day experiment twice (at months 2 and 4) in a 4-month study (N=6 healthy adults; 3 females), and a similar five-day experiment three times (at months 2, 4, and 8) in an 8-month study (N=5 healthy adults; 2 females). During these repeated experiments, CV measures were collected via echocardiography at three assessment time points: 1) after two baseline 8h time in bed (TIB) nights (BL); 2) after a night of total sleep deprivation (TSD); and 3) after two recovery nights of 8-10h TIB (REC). Seated stroke volume (SV), heart rate (HR), cardiac index (CI), left ventricular ejection time (LVET), and systemic vascular resistance index (SVRI) were collected. Data did not significantly differ between the two studies and therefore were pooled together for analysis (N=11). Intraclass correlation coefficients (ICCs) assessed the stability of CV measures after BL and REC. Spearman’s rho assessed the relative rank of individuals’ averaged BL and REC responses across CV measures. Results BL ICCs (0.821-0.944) and REC ICCs (0.806-0.869) comparing months 2 and 4 for all CV measures were almost perfect. The ICCs comparing BL vs. REC measures at month 2 (0.816-0.969) and at month 4 (0.816-0.927) for all CV measures were similarly almost perfect. In the 8-month sample subset, BL ICCs (0.693-939) and REC ICCs (0.770-960) comparing months 2, 4 and 8 for all CV measures were substantial to almost perfect. The ICCs comparing BL vs. REC measures at month 8 for all CV measures were fair to almost perfect (0.314-0.960). Individuals also exhibited significant consistency of responses within CV measures across 2 months and 4 months during BL and REC. Conclusion This is the first demonstration of remarkable robust phenotypic stability of a number of cardiovascular measures across repeated baseline and recovery sleep and across various CV measures in long-duration studies. Support (if any) NASA grants NNX14AN49G and 80NSSC20K0243 (NG)

0209 Cardiovascular Measures Display Robust Phenotypic Stability to Total Sleep Deprivation Across Long-Duration Intervals

Abstract Introduction For the first time, we determined whether individual differences in cardiovascular (CV) measures are observed in response to total sleep deprivation as well as the stability of such responses across 4-month and 8-month long-duration studies. Methods We conducted a five-day experiment twice (at months 2 and 4) in a 4-month study (N=6 healthy adults; 3 females), and a similar five-day experiment three times (at months 2, 4, and 8) in an 8-month study (N=5 healthy adults; 2 females). During these repeated experiments, CV measures were collected via echocardiography or blood pressure monitor [systolic blood pressure (SBP)] at three assessment time points: 1) after two baseline 8h time in bed (TIB) nights (BL); 2) after a night of total sleep deprivation (TSD); and 3) after two recovery nights of 8-10h TIB (REC). Seated SBP, stroke volume (SV), heart rate (HR), cardiac index (CI), left ventricular ejection time (LVET), and systemic vascular resistance index (SVRI) were collected. Data did not significantly differ between the two studies and therefore were pooled together for analysis (N=11). Intraclass correlation coefficients (ICCs) assessed the stability of CV measures during TSD. Spearman’s rho assessed the relative rank of individuals’ averaged TSD-TSD responses across CV measures. Results TSD ICCs across months 2 and 4 were substantial to almost perfect for all CV measures (0.755-0.962). In the 8-month sample subset, TSD ICCs were moderate to almost perfect across 2, 4, and 8 months for all CV measures (0.643-0.944). Individuals also exhibited significant consistency of responses within CV measures: SV was positively correlated with LVET (ρ=0.791, P=0.004), HR was negatively correlated with LVET (ρ=-0.627, P=0.039) and CI was negatively correlated with SVRI (ρ=-0.936, P< 0.001). Conclusion Vulnerability to repeated TSD exposures showed trait-like stability in CV measures across months 2, 4, and 8, with significant consistency of responses within CV measures. For the first time, we demonstrate robust phenotypic stability of cardiovascular measures during total sleep deprivation across 2-month, 4-month and 8-month time points in long-duration studies. Our results herald the use of biomarkers and countermeasures for prediction and mitigation of this critical vulnerability. Support (if any) NASA grants NNX14AN49G and 80NSSC20K0243 (NG)

0207 Acute Total Sleep Deprivation Adversely Impacts Cardiovascular Measures across Long-Duration Intervals

Abstract Introduction For the first time, we comprehensively investigated the effects of repeated exposures to baseline (BL), total sleep deprivation (TSD), and recovery (REC) phases at 2, 4, and 8 months on cardiovascular (CV) measures. Methods We conducted a five-day experiment twice (at months 2 and 4) in a 4-month study (N=6 healthy adults; 3 females), and a similar five-day experiment three times (at months 2, 4, and 8) in an 8-month study (N=5 healthy adults; 2 females). During these repeated experiments, CV measures were collected via echocardiography or blood pressure monitor [systolic and diastolic blood pressure (SBP and DBP)] at three assessment time points: 1) after two baseline 8h time in bed (TIB) nights (BL); 2) after a night of total sleep deprivation (TSD); and 3) after two recovery nights of 8-10h TIB (REC). CV measures were also collected once pre and post study. Seated stroke volume (SV), cardiac index (CI), left ventricular ejection time (LVET), SBP and DBP, systemic vascular resistance index (SVRI), and mean arterial pressure (MAP) were collected. Data did not significantly differ between the two studies and therefore were pooled together for analysis (N=11). Repeated measures ANOVA and post-hoc comparisons corrected for multiple testing examined CV measures across all time points. Results SV, CI, SVRI, LVET, and SBP, but not DBP or MAP, showed significant changes across time. SV increased with TSD compared to pre-study, BL, and post-study at month 2. CI increased with TSD compared to pre-study, BL, REC, and post-study at month 2. SVRI decreased with TSD compared to pre-study, BL, and REC at month 2 and LVET and SBP increased with TSD compared to BL at month 2. In the 8-month sample subset, SBP increased with TSD compared to BL at month 8. Conclusion TSD increased SV, CI, LVET, and SBP, and decreased SVRI, compared to BL at month 2. Notably, TSD also increased SBP compared to BL at month 8, indicating a sustained adverse effect after long-duration repeated exposure to TSD. Overall, SV, CI, SVRI, LVET, and SBP are reliable biomarkers for assessing the harmful long-term cardiovascular effects of TSD. Support (if any) NASA grants NNX14AN49G and 80NSSC20K0243 (NG)

Intelligence predicts better cognitive performance after normal sleep but larger vulnerability to sleep deprivation.

Fluid intelligence is seen as a beneficial attribute, protecting against stress and ill-health. Whether intelligence provides resilience to the cognitive effects of insufficient sleep was tested in the current pre-registered experimental study. Participants (N=182) completed the Raven's test (measuring fluid intelligence) and a normal night of sleep or a night of total sleep deprivation. Sleepiness and four cognitive tests were completed at 22:30 hours (baseline), and the following day after sleep manipulation. At baseline, higher fluid intelligence was associated with faster and more accurate arithmetic calculations, and better episodic memory, but not with spatial working memory, simple attention or sleepiness. Those with higher fluid intelligence were more, not less, impacted by sleep deprivation, evident for arithmetic ability, episodic memoryand spatial working memory. We need to establish a more nuanced picture of the benefits of intelligence, where intelligence is not related to cognitive advantages in all situations.

The Effects of Recovery Sleep on Experimental Pain

Recent research suggests that recovery sleep (RS) has the potential to restore pain sensitivity and modulation after hyperalgesia due to preceding sleep deprivation. However, it has not yet been systematically examined whether the restoration of these pain parameters is driven by sleep characteristics of RS. Thus, the present study assessed changes in experimental pain during RS after total sleep deprivation (TSD) to test whether RS parameters predicted the restoration of the pain system. Thirty healthy participants completed one night of habitual sleep, one night of TSD and a subsequent recovery night. At-home sleep during baseline and recovery was assessed using portable polysomnography and a questionnaire. Before and after each night pressure pain thresholds (PPTs), temporal pain summation (TSP) and conditioned pain modulation (CPM) were assessed. PPTs decreased after TSD and increased following RS, indicating a restoration of pain sensitivity after hyperalgesia. RS characteristics did not predict this restoration, suggesting other mechanisms (eg, changes in serotonergic activity) underlying the observed pain changes. TSP indicated a lack of effect of experimental sleep manipulations on excitatory processes whereas CPM lacked sufficient reliability to investigate inhibitory processes. Thus, results indicate moderate effects of sleep manipulations on pain sensitivity, but not on pain modulation. PerspectiveThis article highlights the potential of recovery sleep to let pain thresholds return to normal following their decrease after a night of total sleep deprivation. In contrast, endogenous pain modulation (temporal pain summation, conditioned pain modulation) was not affected by sleep deprivation and recovery sleep.

Total sleep deprivation decreases saliva ghrelin levels in adolescents.

Ghrelin, a regulator of food intake and energy expenditure, has been shown to be associated with insufficient sleep. The goal of the present study was to investigate the effect of a single night of total sleep deprivation on fasting saliva ghrelin and on nocturnal variation of saliva ghrelin concentration. A further aim of the study was to investigate the influence of body mass index on changes in saliva ghrelin levels. Altogether 35 adolescents (18 boys; age: 13.8 ± 1.14 years) were studied on two subsequent days (sleep and total sleep deprivation). Saliva samples were collected during the two experimental nights at 21:00 hours, 01:00 hours and 06:00 hours. Total-ghrelin concentration showed a continuous increase from the evening until 06:00 hours. This increase was blunted significantly (p=0.003) by total sleep deprivation. Total-ghrelin level was significantly lower (p=0.02) during total sleep deprivation at 06:00 hours (median 403.6pg ml-1 ; 95% confidence interval: 343.1-468.9pg ml-1 ) as compared with values during the sleep condition (median 471.2pg ml-1 ; 95% confidence interval: 205.4-1578.7pg ml-1 ). Acyl-ghrelin levels did not present any change at the three time points, and were not affected by total sleep deprivation. Stratifying the study population according to body mass index (normal weight and overweight/obese groups), the blunting effect of total sleep deprivation was more pronounced in the obese/overweight group (sleep: median 428.2pg ml-1 ; 95% confidence interval: 331.3-606.9pg ml-1 versus total sleep deprivation: median 333.1pg ml-1 ; 95% confidence interval: 261.5-412.9pg ml-1 ; p=0.0479). Saliva total-ghrelin concentrations gradually increased during the night, and total sleep deprivation significantly blunted this increase. This blunting effect was mainly observed in subjects with overweight/obesity. The physiological and clinical implications of the present observation are to be clarified by further studies.

Repeated low-dose caffeine ingestion during a night of total sleep deprivation improves endurance performance and cognitive function in young recreational runners: A randomized, double-blind, placebo-controlled study

ABSTRACT The present study aimed to assess the effects of repeated administration of low-dose caffeine during a night of total sleep deprivation on physical and cognitive performance. Twelve recreational runners (being non-habitual caffeine users) performed four test sessions in a double-blind randomized order after (i) a placebo or 6 mg/kg of caffeine ingestion during a baseline night (BN) or (ii) a placebo or three doses of 2 mg/kg of caffeine during a night of total sleep deprivation (TSD). At each session, they completed an exhaustive run at 75% of the final velocity in a Vameval test (Vvameval) around a 400 m outdoor athletics track and performed the correct detection and reaction time tasks. In comparison with BN, the TSD condition significantly impaired running performance, reaction time, and correct detections. On the contrary, caffeine intake improved exhaustive running performance after BN by 5.2% (p < .001) and after TSD by 8.9% (p < .001), increased correct detections after BN (p < .05) and TSD (p < .05), and decreased reaction time after BN (p < .01) and TSD (p < .05) compared to placebo. Therefore, the repeated ingestion of low-dose caffeine is an effective strategy to counteract the detrimental effects of total sleep deprivation on physical and cognitive performance.

One night of total sleep deprivation impairs decision-making skills, anaerobic performances, mood states, and perceptual responses in elite Kung-Fu athletes

ABSTRACT To explore how one night of total sleep deprivation (TSD) could affect cognitive and physical performances, as well as subjective experiences in 24 elite Kung-Fu athletes (age: 20.2 ± 1.76 years; body mass: 64.67 ± 6.52 kg; height: 1.71 ± 0.04 m). Participants completed, in a randomized counterbalanced order, two tests sessions in the late-afternoon (separated by 72-h recovery) under normal sleep (NS) and TSD conditions. Specific decision-making skills (decision accuracy (DA) and decision time (DT)), various anaerobic-exercises performance (i.e. seated medicine-ball throw (SMBT), horizontal jump (HJ), vertical jump (VJ), isometric back-muscles strength (IBMS), and isometric leg-muscles strength (ILMS)), mood states, and perceptual responses (attention and concentration) were assessed. The TSD was associated with lower values of vigor, and higher values of anxiety, depression, fatigue, anger, confusion, and total mood disturbance, compared to NS. The TSD resulted in lower attention and concentration, compared to NS. Similarly, lower performances of SMBT, HJ, VJ, and ILMS were recorded after TSD compared to NS. For cognitive performances, the TSD resulted in higher DA and lower DT, compared to NS. In summary, one night of TSD elicits negative effects on decision-making and anaerobic performance in Kung-Fu elites through disturbances in mood and attentional capacities.

How Sleep-Deprived People See and Evaluate Others' Faces: An Experimental Study.

BackgroundAcute sleep loss increases the brain’s reactivity toward positive and negative affective stimuli. Thus, despite well-known reduced attention due to acute sleep loss, we hypothesized that humans would gaze longer on happy, angry, and fearful faces than neutral faces when sleep-deprived. We also examined if facial expressions are differently perceived after acute sleep loss.MethodsIn the present, within-subjects study, 45 young adults participated in one night of total sleep deprivation and one night with an 8-hour sleep opportunity. On the morning after each night, an eye tracker was used to measure participants’ time spent fixating images of happy, angry, fearful, and neutral faces. Participants also evaluated faces’ attractiveness, trustworthiness, and healthiness on a 100-mm visual analog scale.ResultsFollowing sleep loss, participants struggled more fixating the faces than after sleep. The decrease in total fixation duration ranged from 6.3% to 10.6% after sleep loss (P<0.001). Contrary to our hypothesis, the reduction in total fixation duration occurred irrespective of the displayed emotion (P=0.235 for sleep*emotion interaction) and was also present for the upper (P<0.001) but not the lower part of the faces (except for the lower part of angry faces). Overall, faces were evaluated as less trustworthy (−2.6 mm) and attractive (−3.6 mm) after sleep loss (p<0.05).DiscussionFacial expressions are crucial for social interactions. Thus, spending less time fixating on faces after acute sleep loss may come along with several problems for social interactions, eg, inaccurate and delayed judgment of the emotional state of others. In addition, more negative social impressions of others may lead to social withdrawal in sleep-deprived humans.

Can a brief survey identify U.S. Army Soldiers who are behaviorally and genetically resilient to sleep loss?

There are replicable inter-individual differences in cognitive responsivity to sleep loss. Genetic allele variations have been linked with behavioral differences in cognitive performance under these conditions, yet less burdensome tests or screeners are not available. This study tested whether a survey can classify U.S. Army Soldiers as cognitively vulnerable or resilient to sleep loss and whether Soldiers in these differentiated groups have the expected allele variants. Six genetic targets were sequenced from 75 Soldiers. Cognition was tested after a night of total sleep deprivation during a military exercise. The Iowa Resilience to Sleeplessness Test (iREST) was administered. A Wilcoxon Rank Sum test showed the iREST score of 2.5/5 differentiated groups behaviorally on all cognitive tests. Chi-squared tests showed that for the Catechol-O-Methyltransferase (COMT) gene, 82% of behaviorally vulnerable soldiers had alleles linked with vulnerability, compared with 41% of behaviorally genetic soldiers. If these findings are replicated, the iREST could be used to help military leaders make decisions about personnel placement when sleep loss is unavoidable.

Effects of Repeated Low-dose Caffeine Ingestion During a Night of Total Sleep Deprivation on Physical Performance and Psychological State in Young Recreational Runners

Background: Caffeine is frequently consumed by athletes to maintain alertness in conditions of sleep loss. However, the effect of caffeine ingestion during total sleep deprivation during aerobic exercise remains questionable. Objectives: The present study aimed to assess the effects of repeated intake of low-dose caffeine during a night of total sleep deprivation on endurance performance and psychological states. Methods: Twelve recreational runners performed four test sessions in a double-blind randomized order after a placebo or 6 mg/kg of caffeine ingestion after a baseline night (BN) or three doses of 2 mg/kg of caffeine during a night of total sleep deprivation (TSD). At each session, they completed an exhaustive run around a 400 m athletics track and performed the Feeling Scale test. ANOVA with repeated measures followed by paired t-tests was used to analyze the data. Results: In comparison with BN, the TSD condition significantly impaired running performance (P &lt; 0.001). On the contrary, caffeine administration improved endurance running performance (P &lt; 0.001) and increased feeling of well-being (P &lt; 0.05) after TSD night as compared to placebo. Conclusions: Repeated ingestion of low-dose caffeine is an effective way to mitigate the negative effects of total sleep deprivation on endurance performance and mood states.

Quarreling After a Sleepless Night: Preliminary Evidence of the Impact of Sleep Deprivation on Interpersonal Conflict

Although poor sleep has been found to correlate with deteriorations in romantic relationships, its causal impact on interpersonal conflict has not previously been studied. Therefore, 30 couples were randomly assigned to either a single night of total sleep deprivation or a night of normal sleep to test the effects of sleep deprivation on couples’ conflict. After the experimental night, all participants discussed a topic of recurrent conflict for 15 min. We collected pre- and post-conflict measures of cortisol, self-reports of feelings, and satisfaction with the conflictual discussion. Multilevel analyses revealed higher cortisol levels during conflict and less positive affect prior to and after the conflict for sleep-deprived couples compared to couples in the control condition. These findings provide initial evidence for a causal negative impact of sleep deprivation on couples’ conflicts.

Impaired Vigilant Attention Partly Accounts for Inhibition Control Deficits After Total Sleep Deprivation and Partial Sleep Restriction.

PurposeSleep loss impairs a range of neurobehavioral functions, particularly vigilant attention and arousal. However, the detrimental effects of sleep deprivation on inhibition control and its relationship to vigilant attention impairments remain unclear. This study examined the extent to which vigilant attention deficits contribute to inhibition control performance after one night of total sleep deprivation (TSD) and two nights of partial sleep restriction (PSR).Participants and MethodsWe analyzed data from N = 49 participants in a one-night of TSD experiment, N=16 participants in a control experiment without sleep loss, and N = 16 participants in a two-nights of PSR experiment (time in bed, TIB = 6 h for each night). Throughout waking periods in each condition, participants completed the psychomotor vigilance test (PVT), which measures vigilant attention, and the Go/No-Go task, which measures inhibition control.ResultsAfter TSD and PSR, participants displayed significantly slower reaction times (RT) and more lapses in PVT performance, as well as slower Go RT and more errors of omission during the Go/No-Go task. PVT deficits accounted for 18.0% of the change in Go RT and 12.4% of the change in errors of omission in the TSD study, and 23.7% of the change in Go RT and 20.3% of the change in errors of omission in the PSR study.ConclusionBoth TSD and PSR impaired inhibition control during the Go/No-Go task, which can be partly accounted for by vigilant attention deficits during the PVT. These findings support the key role of vigilant attention in maintaining overall neurobehavioral function after sleep loss.