Psychomotor Vigilance Performance Research Articles

Association between sleep-disordered breathing and psychomotor vigilance performance in elementary school children

Association between sleep-disordered breathing and psychomotor vigilance performance in elementary school children

Effects of work-related electronic communication during non-working hours after work from home and office on fatigue, psychomotor vigilance performance and actigraphic sleep: observational study on information technology workers

ObjectivesThis study examined the effects of work-related electronic communication (WREC) during non-working hours in the work from home or office setting on health.MethodsThe study recruited 98 information technology workers in...

Psychomotor Vigilance Performance in Participants with Excessive Daytime Sleepiness in Obstructive Sleep Apnea or Narcolepsy Compared withSAFTE-FAST Model Predictions.

Excessive daytime sleepiness (EDS) associated with narcolepsy or obstructive sleep apnea (OSA) can impair vigilance/attention. Solriamfetol, a dopamine/norepinephrine reuptake inhibitor, is approved to treat EDS associated with narcolepsy (75-150mg/day) or OSA (37.5-150mg/day). The analysis reported here explored the use of the Sleep, Activity, Fatigue, and Task Effectiveness (SAFTE) model (used in transport industries to model performance based on accumulated sleep and circadian variability) as a substitute for healthy controls using psychomotor vigilance task (PVT) data collected during clinical studies. Data were analyzed from two phase 2 studies of solriamfetol in adults with OSA (NCT02806895, EudraCT 2015-003930-28) or narcolepsy (NCT02806908, EudraCT 2015-003931-36). Participants were randomly assigned 1:1 to solriamfetol 150mg/day (3days) followed by 300mg/day (4days), or placebo (7days), then crossed over to the other treatment. Actual task effectiveness scores were calculated from average PVT inverse reaction time (pre-dose; 2h post-dose; 6h post-dose). Actigraphy-derived sleep intervals were used in SAFTE to determine modeled healthy control task effectiveness scores. In participants with OSA (N = 31) on placebo or solriamfetol, actual and modeled healthy control task effectiveness did not differ at any time point. In participants with narcolepsy (N = 20) on placebo, actual task effectiveness at 2h post-dose was lower than modeled healthy control task effectiveness (nominal P = 0.03), a difference not present with solriamfetol. There was no main effect of solriamfetol on actual or modeled healthy control task effectiveness across time points. This study represents a novel application of the SAFTE biomathematical model to approximate healthy controls in sleep disorder research and provides valuable lessons that may optimize future research. Future studies should perform a priori power analyses for model-tested outcomes and use sleep measures that capture sleep fragmentation characteristic of sleep disorders for sleep input (e.g., total sleep time rather than time in bed). NCT02806895, EudraCT 2015-003930-28: A Randomized, Double-Blind, Placebo-Controlled, Crossover On-Road Driving Study Assessing the Effect of JZP-110 on Driving Performance in Subjects With Excessive Sleepiness Due to Obstructive Sleep Apnea. NCT02806908, EudraCT 2015-003931-36: A Randomized, Double-Blind, Placebo-Controlled, Crossover On-Road Driving Study Assessing the Effect of JZP-110 on Driving Performance in Subjects With Excessive Sleepiness Due to Narcolepsy.

A systematic review of sleep deprivation and neurobehavioral function in young adults

AimTo examine the effect of sleep deprivation (total and partial) on neurobehavioral function compared to a healthy sleep opportunity (7‐9 h) in young adults 18–30 years. BackgroundMore than one-third of young adults are sleep deprived, which negatively affects a range of neurobehavioral functions, including psychomotor vigilance performance (cognitive), affect, and daytime sleepiness. MethodsA systematic review of randomized controlled trials (RCTs) on sleep deprivation and neurobehavioral function. Multiple electronic databases (Cochrane Central Registry of Controlled Trials [CENTRAL], PubMed, PsycINFO, CINAHL, and Web of Science) were searched for relevant RCTs published in English from the establishment of each database to December 31, 2020. ResultsNineteen RCTs were selected (N = 766, mean age = 23.7 ± 3.1 years; 44.8% female). Seven were between-person (5 were parallel-group designs and 2 had multiple arms), and 12 were within-person designs (9 were cross over and 3 used a Latin square approach). Total sleep deprivation had the strongest detrimental effect on psychomotor vigilance performance, with the largest effects on vigilance tasks in young adults in the included studies. ConclusionAcute sleep deprivation degrades multiple dimensions of neurobehavioral function including psychomotor vigilance performance, affect, and daytime sleepiness in young adults. The effect of chronic sleep deprivation on the developing brain and associated neurobehavioral functions in young adults remains unclear.

Sleep quality, occupational factors, and psychomotor vigilance performance in the U.S. Navy sailors.

This field study (a) assessed sleep quality of sailors on the U.S. Navy (USN) ships while underway, (b) investigated whether the Pittsburgh Sleep Quality Index (PSQI) scores were affected by occupational factors and sleep attributes, and (c) assessed whether the PSQI could predict impaired psychomotor vigilance performance. Longitudinal field assessment of fit-for-duty USN sailors performing their underway duties (N = 944, 79.0% males, median age 26 years). Participants completed questionnaires, wore actigraphs, completed logs, and performed the wrist-worn 3-min Psychomotor Vigilance Task (PVT). Sailors slept on average 6.60 ± 1.01 h/day with 86.9% splitting their sleep into more than one episode/day. The median PSQI Global score was 8 (interquartile range [IQR] = 5); 80.4% of the population were classified as "poor sleepers" with PSQI scores >5. PSQI scores were affected by sailor occupational group, rank, daily sleep duration, and number of sleep episodes/day. Sleep quality showed a U-shape association with daily sleep duration due to the confounding effect of split sleep. Sailors with PSQI scores >9 had 21.1% slower reaction times (p < 0.001) and 32.8%-61.5% more lapses combined with false starts (all p < 0.001) than sailors with PSQI scores ≤9. Compared to males and officers, females and enlisted personnel had 86% and 23% higher risk, respectively, of having PSQI scores >9. Sailors in the PSQI > 9 group had more pronounced split sleep. Working on Navy ships is associated with elevated PSQI scores, a high incidence of poor sleep, and degraded psychomotor vigilance performance. The widely used PSQI score>5 criterion should be further validated in active-duty service member populations.

0821 Gender Differences in Sailor Well-Being, Sleep-Related Behaviors, and Psychomotor Vigilance Performance in the United States Navy

Abstract Introduction Approximately 18% of US Navy sailors are females. Research has shown gender-related differences in the prevalence of sleep disorders in active duty personnel (Foster et al., 2017). Specifically, insomnia, depression, and anxiety are more prevalent in females, while obstructive sleep apnea is more prevalent in males. We have studied the sleep patterns and fatigue levels of crew members on more than 30 US Navy ships. The current study focuses on gender differences in well-being, sleep-related behaviors, and psychomotor vigilance performance of sailors in the US Navy. Methods Using a longitudinal, naturalistic observation paradigm, data were collected from crewmembers on nine USN ships while performing their normal underway duties. Participants (N=1,056) tended to be young (on average 27 years of age), predominantly male (80.6%), and enlisted (84.8%). We assessed average daytime alertness (Epworth Sleepiness Scale), insomnia symptoms (Insomnia Severity Index), mood (Profile of Mood States), and sleep quality (Pittsburgh Sleep Quality Index). Sleep was assessed with actigraphy and logbooks. Sailors performed a 3-minute version of the Psychomotor Vigilance Task (PVT), which was built into their wrist-worn actigraph. Results Compared to males, female sailors reported more depressive symptoms (p=0.042) and less vigor (p&amp;lt;0.001). Females slept more (daily sleep duration: p&amp;lt;0.001) but their sleep was split into more episodes than their male counterparts (p=0.029). Fewer females reported a regular exercise routine (p=0.033). In addition, females report consuming fewer energy drinks (p=0.007), and using fewer nicotine products (p=0.013). Lastly, consistent with findings from civilian populations, female sailors had slower reaction times on the PVT (p&amp;lt;0.001) and experienced more lapses combined with false starts (p&amp;lt;0.001) than their male counterparts. Conclusion Compared to their male peers, female sailors tend to report higher levels of depression and lower levels of vigor. They experience more pronounced split sleep, are less likely to report having an exercise routine, and have poorer performance on the PVT. Fewer females report using energy drinks and nicotine products. Support This research was supported by the Naval Medical Research Center’s Advanced Medical Development Program, the US Navy 21st Century Sailor Office, and the US Navy OPNAV N1.

Psychomotor Vigilance Impairment During Total Sleep Deprivation Is Exacerbated in Sleep-Onset Insomnia.

PurposeIndividuals with primary insomnia frequently report cognitive impairment as a next-day consequence of disrupted sleep. Studies attempting to quantify daytime impairment objectively in individuals with insomnia have yielded mixed results, with evidence suggesting impairments in aspects of executive functioning but not psychomotor vigilance. It has been suggested that persons with insomnia may have latent performance deficits for which they would be able to compensate effectively under normal daytime circumstances – suggesting that any such deficits may be exposed through perturbation. In this context, we used a laboratory-based total sleep deprivation (TSD) paradigm to investigate psychomotor vigilance performance in individuals with chronic sleep-onset insomnia as compared to healthy normal controls.Participants and methodsFourteen participants, seven individuals with chronic sleep-onset insomnia (ages 24–40y) and seven age-matched, healthy normal sleepers completed a highly controlled in-laboratory study involving 38 h of TSD. A 10 min and a 3 min version of the psychomotor vigilance test (PVT) were administered every 3 h during TSD.ResultsIn both the individuals with sleep-onset insomnia and the age-matched normal sleepers, lapses of attention and false starts on the PVT were relatively infrequent during the first 16 h of the TSD period, but increased significantly when wakefulness was extended beyond 16 h. However, the effects of TSD on PVT performance were considerably exacerbated in the sleep-onset insomnia group, which showed about twice as many lapses of attention, more than twice as many false starts, and approximately twice as big a time-on-task effect on the 10 min PVT as the age-matched normal sleepers group, with similar findings on the 3 min PVT.ConclusionThese findings indicate that daytime impairment reported by individuals with sleep-onset insomnia has an objective performance component that is exposed during TSD. Thus, persons with sleep-onset insomnia could be at increased risk of performance impairment in settings that involve extended wakefulness. This underscores the importance of treating insomnia and suggests that laboratory sleep deprivation studies could serve to document the effectiveness of treatment approaches.

0617 Working Memory and Psychomotor Vigilance Performance After Brief Naps in Hypersomnolent Patients: MSLT Correlates

0617 Working Memory and Psychomotor Vigilance Performance After Brief Naps in Hypersomnolent Patients: MSLT Correlates

Impact of work and rest schedules on performance and mood in members of the US military

Sleep patterns, psychomotor vigilance performance, work demands and mood were assessed in crewmembers during rotating 5-h ON/10-h OFF (5/10) watchstanding schedule. Within the 3-day cycle of the 5/10, sleep occurred at distinctly different times each day. On two of these days, sailors typically received only brief, 4-h sleep episodes followed by periods of sustained wakefulness. Crewmembers received approximately seven hours of sleep daily, but reported excessive fatigue and dissatisfaction with their schedule. Crewmembers’ mood worsened. Psychomotor vigilance performance was degraded compared to circadian-aligned schedules.

The Effect of Habitual Exercise on Daytime Sleepiness and Mood of US Navy Sailors

As part of a broader study, this work investigates if habitual exercise protects against mood deterioration and daytime sleepiness in Sailors during underway operations. Previous work has shown that unfavorable watchstanding schedules have negative effects on sleep quality, subjective levels of fatigue, mood, and psychomotor vigilance performance. The participants were crewmembers of a U.S. Navy aircraft carrier (N=193), working on two different watchstanding schedules. Epworth Sleepiness Scale (ESS) and profile of mood state (POMS) scores were compared between participants who reported exercising &lt; 3 times/week and ≥3 times/week. During the course of the underway, ESS and POMS scores changed more favorably for the crewmembers who exercised 3 or more times/week compared to their peers who exercised less. The effect of working out was more prominent in the less favorable shift schedule. These results suggest that habitual exercise can be a protective buffer against some of the negative effects of watchstanding while underway.

Computational cognitive modeling of the temporal dynamics of fatigue from sleep loss.

Computational models have become common tools in psychology. They provide quantitative instantiations of theories that seek to explain the functioning of the human mind. In this paper, we focus on identifying deep theoretical similarities between two very different models. Both models are concerned with how fatigue from sleep loss impacts cognitive processing. The first is based on the diffusion model and posits that fatigue decreases the drift rate of the diffusion process. The second is based on the Adaptive Control of Thought - Rational (ACT-R) cognitive architecture and posits that fatigue decreases the utility of candidate actions leading to microlapses in cognitive processing. A biomathematical model of fatigue is used to control drift rate in the first account and utility in the second. We investigated the predicted response time distributions of these two integrated computational cognitive models for performance on a psychomotor vigilance test under conditions of total sleep deprivation, simulated shift work, and sustained sleep restriction. The models generated equivalent predictions of response time distributions with excellent goodness-of-fit to the human data. More importantly, although the accounts involve different modeling approaches and levels of abstraction, they represent the effects of fatigue in a functionally equivalent way: in both, fatigue decreases the signal-to-noise ratio in decision processes and decreases response inhibition. This convergence suggests that sleep loss impairs psychomotor vigilance performance through degradation of the quality of cognitive processing, which provides a foundation for systematic investigation of the effects of sleep loss on other aspects of cognition. Our findings illustrate the value of treating different modeling formalisms as vehicles for discovery.

Comparison of the 3/9 and 6/6 Watchstanding Schedules for Crewmembers of a U.S. Navy destroyer

This naturalistic study of 52 sailors on the USS Jason Dunham (DDG-109) compared actigraphic sleep and psychomotor vigilance performance of crewmembers working a 3hours-on/9hours-off (“3/9”) with the performance of their counterparts who worked a 6hours-on/6hours-off (“6/6”) watchstanding schedule. Crewmembers on the 3/9 slept more (6.46±0.77 hours) and reported less daytime sleepiness (Epworth Sleepiness Scale (ESS) score = 10.7±3.70) than their peers on the 6/6 schedule (sleep 5.89±0.87 hours; ESS = 13.1±3.45). The length of the workday for participants on the 6/6 schedule was 15 hours compared to 12.2 hours for crewmembers on the 3/9. Based on 11 of 13 Psychomotor Vigilance Task metrics, performance of crewmembers on the 6/6 schedule had significantly greater variability than the 3/9 sailors (p&lt;0.05). Overall, participants evaluated the 6/6 as being worse and the 3/9 as the better schedule. Results showed that the 3/9 outperformed the 6/6 in terms of daily sleep duration, fatigue levels, psychomotor vigilance performance, and acceptance from the participants.

Effects of Shift Work on the Postural and Psychomotor Performance of Night Workers.

The purpose of the study was to investigate the effects of shift work on the psychomotor and postural performance of night workers. The study included 20 polysomnography technicians working schedule of 12-h night shift by 36-h off. On the first day of protocol, the body mass and height were measured, and an actigraph was placed on the wrist of each participant. On the second day of protocol, sleepiness by Karolinska Sleepiness Scale, postural control by force platform (30 seconds) and psychomotor performance by Psychomotor Vigilance Task (10 minutes) were measured before and after 12-h night work. Results showed that after 12-h night work, sleepiness increased by 59% (p<0.001), postural control variables increased by 9% (p = 0.048), and 14% (p = 0.006). Mean reaction time, and the number of lapses of attention increased by 13% (p = 0.006) and 425% (p = 0.015), respectively, but the mean reciprocal reaction time decreased by 7%. In addition, there were correlations between sleepiness and postural control variables with opened eyes (r = 0.616, 95% confidence interval [CI] = 0.361–0.815; r = 0.538; 95% CI = 0.280–0.748) and closed eyes (r = 0.557; 95% CI = 0.304–0.764, r = 0497; 95% CI = 0.325–0.715) and a pronounced effect of sleepiness on postural sway (R2 = 0.393; 95% CI = 0.001–0.03). Therefore, 12-h night work system and sleepiness showed a negative impact in postural and psychomotor vigilance performance of night workers. As unexpected, the force platform was feasibility to detect sleepiness in this population, underscoring the possibility of using this method in the workplace to prevent occupational injuries and accidents.

Gray matter volume and executive functioning correlate with time since injury following mild traumatic brain injury

Most people who sustain a mild traumatic brain injury (mTBI) will recover to baseline functioning within a period of several days to weeks. A substantial minority of patients, however, will show persistent symptoms and mild cognitive complaints for much longer. To more clearly delineate how the duration of time since injury (TSI) is associated with neuroplastic cortical volume changes and cognitive recovery, we employed voxel-based morphometry (VBM) and select neuropsychological measures in a cross-sectional sample of 26 patients with mTBI assessed at either two-weeks, one-month, three-months, six-months, or one-year post injury, and a sample of 12 healthy controls. Longer duration of TSI was associated with larger gray matter volume (GMV) within the ventromedial prefrontal cortex (vmPFC) and right fusiform gyrus, and better neurocognitive performance on measures of visuospatial design fluency and emotional functioning. In particular, volume within the vmPFC was positively correlated with design fluency and negatively correlated with symptoms of anxiety, whereas GMV of the fusiform gyrus was associated with greater design fluency and sustained visual psychomotor vigilance performance. Moreover, the larger GMV seen among the more chronic individuals was significantly greater than healthy controls, suggesting possible enlargement of these regions with time since injury. These findings are interpreted in light of burgeoning evidence suggesting that cortical regions often exhibit structural changes following experience or practice, and suggest that with greater time since an mTBI, the brain displays compensatory remodeling of cortical regions involved in emotional regulation, which may reduce distractibility during attention demanding visuo-motor tasks.

Operational assessment of the 5-h on/10-h off watchstanding schedule on a US Navy ship: sleep patterns, mood and psychomotor vigilance performance of crewmembers in the nuclear reactor department

We assessed sleep patterns, psychomotor vigilance performance, work demands and mood of 77 crewmembers of USS NIMITZ (CVN-68) on the rotating 5-h on/10-h off (5/10) watchstanding schedule. Within the 3-day cycle of the 5/10, sleep occurred at distinctly different times each day. On two of these days, sailors typically received only brief, 4-h sleep episodes followed by periods of sustained wakefulness (approximately 22 and 20 h). Crewmembers received approximately seven hours of sleep daily, but reported excessive fatigue and dissatisfaction with their schedule. Crewmembers’ mood worsened significantly over the course of the underway phase. Psychomotor vigilance performance (reaction times, lapses) was significantly degraded compared to performance when working circadian-aligned schedules. Overall, standing watch on the 5/10 schedule, combined with other work duties, resulted in poor sleep hygiene. Crewmembers on the 5/10 experienced periodic bouts of sustained wakefulness and accrued a significant sleep debt due to extended workdays and circadian-misaligned sleep.Practitioner summary: We assessed crewmembers’ sleep patterns, psychomotor vigilance performance and work demands when working a rotating 5-h on/10-h off (5/10) watchstanding schedule. The 5/10, combined with other work duties, resulted in poor sleep hygiene. Crewmembers experienced periodic bouts of sustained wakefulness and accrued a significant sleep debt due to extended workdays and circadian-misaligned sleep.

The Effect of Ship Department on Crew Sleep Patterns and Psychomotor Vigilance Performance

U.S. Navy ship crews are organizationally divided into departments, i.e., functional groups with specific tasks and an officer in charge. The objective of this study is to assess the effect of ship departments on crew sleep patterns and psychomotor vigilance performance. Crewmembers (N=93) from an Arleigh Burke-type destroyer participated in a 16-day quasi-experimental study while the ship was forward deployed. Each sailor wore an actigraph, completed a daily activity log, and performed a 3-minute psychomotor vigilance test (PVT) before and after standing watch. Actigraphy results show that crewmembers were chronically sleep deprived, receiving on average 6.6 hours of daily sleep. Rest and sleep opportunities were varied significantly depending on the department to which the crewmember belongs. Specifically, the Operations department, followed by Engineering, had the worst sleep patterns as indicated by reduced and fragmented sleep. Using actigraphic recordings, approximately 22% of the participants occasionally napped during their night watch. Although not statistically significant due to its large variability, the pattern of PVT results agrees with the sleep analysis. In conclusion, this study provides evidence that the department to which a crewmember belongs is a factor to be taken into account when assessing performance at sea. In our sample, results demonstrate that the two departments most affected are the Operations and the Engineering. Both of these departments have critical duties while underway, yet they experience the most sleep deprivation. Future efforts should strive to further quantify this phenomenon and to address methods to ameliorate the problem.

Comparison of a Circadian-based and a Forward Rotating Watch Schedules on Sleep, Mood, and Psychomotor Vigilance Performance

In the military, any degradation in performance may have serious implications, potentially resulting in loss of life or affecting mission accomplishment. The maritime environment imposes the additional unique challenges of waterborne motion on the shipboard crew. Additionally, the U.S. Navy’s 24/7 operational requirements mandate rigorous equipment monitoring and shiftwork. This study assesses how crewmember sleep hygiene and psychomotor vigilance performance is affected by a shift from traditional work schedules to an alternative circadian-based schedule. Twenty-eight sailors were assessed while working two watch schedules, a conventional 5-hours on/10-hours off (5/10) rapidly rotating schedule, and an alternative 3-hours on/9-hours off (3/9) fixed schedule. Average daily sleep duration was the same for both watch schedules. However, compared to their scores on the 5/10, sailors on the 3/9 had significantly less daytime sleepiness, improved mood, 30% faster reaction times, and had 40% to 50% fewer errors (i.e., lapses combined with false starts). The significant improvements in performance, mood, and sleep hygiene observed in this within-subjects study suggest that circadian watch schedules should be chosen rather than non-circadian aligned schedules.

TNFα G308A polymorphism is associated with resilience to sleep deprivation-induced psychomotor vigilance performance impairment in healthy young adults.

Cytokines such as TNFα play an integral role in sleep/wake regulation and have recently been hypothesized to be involved in cognitive impairment due to sleep deprivation. We examined the effect of a guanine to adenine substitution at position 308 in the TNFα gene (TNFα G308A) on psychomotor vigilance performance impairment during total sleep deprivation. A total of 88 healthy women and men (ages 22-40) participated in one of five laboratory total sleep deprivation experiments. Performance on a psychomotor vigilance test (PVT) was measured every 2-3h. The TNFα 308A allele, which is less common than the 308G allele, was associated with greater resilience to psychomotor vigilance performance impairment during total sleep deprivation (regardless of time of day), and also provided a small performance benefit at baseline. The effect of genotype on resilience persisted when controlling for between-subjects differences in age, gender, race/ethnicity, and baseline sleep duration. The TNFα G308A polymorphism predicted less than 10% of the overall between-subjects variance in performance impairment during sleep deprivation. Nonetheless, the differential effect of the polymorphism at the peak of performance impairment was more than 50% of median performance impairment at that time, which is sizeable compared to the effects of other genotypes reported in the literature. Our findings provided evidence for a role of TNFα in the effects of sleep deprivation on psychomotor vigilance performance. Furthermore, the TNFα G308A polymorphism may have predictive potential in a biomarker panel for the assessment of resilience to psychomotor vigilance performance impairment due to sleep deprivation.

Psychomotor vigilance performance predicted by Epworth Sleepiness Scale scores in an operational setting with the United States Navy.

It is critical in operational environments to identify individuals who are at higher risk of psychomotor performance impairments. This study assesses the utility of the Epworth Sleepiness Scale for predicting degraded psychomotor vigilance performance in an operational environment. Active duty crewmembers of a USA Navy destroyer (N = 69, age 21-54 years) completed the Epworth Sleepiness Scale at the beginning of the data collection period. Participants wore actigraphs and completed sleep diaries for 11 days. Psychomotor vigilance tests were administered throughout the data collection period using a 3-min version of the psychomotor vigilance test on the actigraphs. Crewmembers with elevated scores on the Epworth Sleepiness Scale (i.e. Epworth Sleepiness Scale >10) had 60% slower reaction times on average, and experienced at least 60% more lapses and false starts compared with individuals with normal Epworth Sleepiness Scale scores (i.e. Epworth Sleepiness Scale ≤ 10). Epworth Sleepiness Scale scores were correlated with daily time in bed (P < 0.01), sleep (P < 0.05), mean reaction time (P < 0.001), response speed 1/reaction time (P < 0.05), slowest 10% of response speed (P < 0.001), lapses (P < 0.01), and the sum of lapses and false starts (P < 0.001). In this chronically sleep-deprived population, elevated Epworth Sleepiness Scale scores identified that subset of the population who experienced degraded psychomotor vigilance performance. We theorize that Epworth Sleepiness Scale scores are an indication of personal sleep debt that varies depending on one's individual sleep requirement. In the absence of direct performance metrics, we also advocate that the Epworth Sleepiness Scale can be used to determine the prevalence of excessive sleepiness (and thereby assess the risk of performance decrements).

Insights into Behavioral Vulnerability to Differential Sleep Pressure and Circadian Phase from a Functional ADA Polymorphism

Sleep loss affects human behavior in a nonuniform manner, depending on the cognitive domain and also the circadian phase. Besides, evidence exists about stable interindividual variations in sleep loss-related performance impairments. Despite this evidence, only a few studies have considered both circadian phase and neurobehavioral domain when investigating trait-like vulnerability to sleep manipulation. By applying a randomized, crossover design with 2 sleep pressure conditions (40 h sleep deprivation vs. 40 h multiple naps), we investigated the influence of a human adenosine deaminase (ADA) polymorphism (rs73598374) on several behavioral measures throughout nearly 2 circadian cycles. Confirming earlier studies, we observed that under sleep deprivation the previously reported vulnerable G/A-allele carriers felt overall sleepier than G/G-allele carriers. As expected, this difference was no longer present when sleep pressure was reduced by the application of multiple naps. Concomitantly, well-being was worse in the G/A genotype under sleep loss when compared to the nap protocol, and n-back working memory performance appeared to be specifically susceptible to sleep-wake manipulation in this genotype. When considering psychomotor vigilance performance, however, a higher sensitivity to sleep-wake manipulation was detected in homozygous participants, but specifically at the end of the night and only for optimal task performance. Although these data are based on a small sample size and hence require replication (12 G/A- and 12 G/G-allele carriers), they confirm the assumption that interindividual differences regarding the effect of sleep manipulation highly depend on the cognitive task and circadian phase, and thus emphasize the necessity of a multimethodological approach. Moreover, they indicate that napping might be suitable to counteract endogenously heightened sleep pressure depending on the neurobehavioral domain.