Vigilance Test Research Articles

0551 Predicting Daytime Alertness Impairment in Obstructive Sleep Apnea

Abstract Introduction Obstructive sleep apnea (OSA) reduces daytime alertness leading to social and occupational impairment. The Maintenance of Wakefulness Test (MWT), a gold-standard test for daytime alertness, is time-consuming and not routinely available in clinical practice. We examined EEG-based and clinical parameters derived from diagnostic polysomnography (PSG) as predictors of alertness impairment in adults with OSA. Methods Eighty-two participants with untreated OSA on diagnostic PSG (apnea hypopnea index, AHI ≥5/hour), enrolled in a two-center clinical trial were included. The day following PSG, each participant completed four 40-minute MWT and four 10-minute Psychomotor Vigilance Tests (PVT). The outcomes were MWT mean sleep latency (MSL) and PVT lapses (reaction time ≥500 milliseconds, square root transformed). Three multiple linear regression models were used: 1. “standard predictors” (total sleep time, TST, percent REM and slow wave sleep, AHI, time < 90% oxygen saturation, and arousal index), 2. “novel predictors” derived by spectral analysis and averaged across right and left central EEG (normalized EEG power, odds ratio product; ORP parameters, and spindle characteristics), and 3. combined standard and novel predictors. Age, sex, and body mass index (BMI) were included in each model, and backward elimination (step AIC) was used for models 2 and 3. Results Participants were middle-aged (mean ± standard deviation, SD 53.5±8.7 years), with moderate OSA (AHI 33.8±18.2) and daytime sleepiness (Epworth Sleepiness Scale 11.7±3.9), and 86% were men. The adjusted r2 for MSL were: model 1=0.09, model 2=0.16, and model 3=0.27, and PVT lapses were: model 1=0.09, model 2=0.31, and model 3=0.34. For MSL, the significant predictors in model 3 included TST (t-statistic -3.59, p=0.0007), REM% (2.51, p=0.01), ORP-9 (2.95, p=0.004), ORP NREM (-3.15, p=0.002), spindle frequency (-2.95, p=0.004), and normalized EEG power (-2.59, p=0.01). For PVT lapses, model 3 predictors included 2.25-2.5 ORP% (-2.91, p=0.005), normalized EEG power (3.22, p=0.002), spindle power (-4.30, p< 0.0001), spindle frequency (2.83, p=0.006), and sex (men vs. women, -2.56, p=0.01). Conclusion We have identified several novel PSG EEG-based predictors of impaired daytime alertness in OSA that will improve occupational evaluation and prognostication in OSA after future validation. Support (if any) National Institutes of Health, UM1-HL112856, UL1TR001422, and UL1TR002003.

0536 Impact of Positive Airway Pressure Therapy on Clinical Outcomes in Older Veterans with Comorbid COPD and OSA: An Update

Abstract Introduction Cognitive impairment in older Veterans is an independent predictor of subsequent mortality and disability. Pilot data indicate that patients with OSA-COPD Overlap Syndrome (OVS) may have reduced sleep quality, cognitive function and quality of life (QoL). However, there are no prior systematic studies evaluating treatment paradigms in patients with OVS. Our ongoing clinical trial is investigating whether positive airway pressure (PAP) therapy alleviates sleep disturbances, sleepiness, and improves cognitive function and QoL in older adults with OVS. Methods The design is a prospective parallel group randomized controlled trial in Veterans 60 years and older, with moderate-to-severe OSA with concomitant COPD (OVS). 225 eligible participants will be randomized to two treatment groups (PAP and conservative care) in 2:1 ratio for a duration of 6 months. Participants on the conservative care arm are required to follow good sleep habits and sleep hygiene, and on the PAP arm, in addition, are required to be adherent to PAP treatment (CPAP or Bilevel PAP, as required). Sleep questionnaires are administered to evaluate sleepiness, sleep quality, and general and disease specific QoL. Cognitive function is evaluated using Trail Making Test Part A and B, Paced Auditory Serial Addition Test, Stroop Task, Digit Coding, Hopkins Verbal Learning Test-R, Weschler Abbreviated Scale Intelligence II, Weschler Memory Scale IV, and Psychomotor Vigilance Test, respectively. All tests are administered at baseline visit, 3 months, and 6 months. Results In year-2 of the study, we have screened 7878 Veterans, enrolled 137 participants, randomized 34 participants (31 males, 3 females; age: 70.7±6.6 years, BMI: 29.6±6.7 kg/m2, AHI: 47±22 events/hr, spirometry FEV1: 60.8±11.7% predicted, arterial blood gas (n=22) pCO2:41.2 ±3.6 mmHg, ESS: 1.9 ±2.4); 15 have completed the study per the protocol. Analysis of data will be completed at the end of the RCT. Conclusion Our research seeks to systematically study the effects of treating a novel target (OVS) to maximize daytime function and QoL, while also providing a framework for early treatment of mild cognitive impairment in vulnerable older Veterans. Support (if any) VHA RR&D Merit Award # 1I01RX003124-01

0178 2B-Alert App: Personalized Caffeine Recommendations for Optimal Alertness

Abstract Introduction Sleep loss causes millions of individuals around the world to carry out daily activities with impaired alertness, affecting injury risk and productivity. If properly consumed, caffeine can safely and effectively mitigate the effects of sleep loss on alertness. However, to be effective, caffeine should be consumed at the right time and in the correct amount, depending on sleep history, work schedule and, importantly, sensitivity to sleep loss. Here, we present the 2B-Alert app, a unique smartphone application with capabilities to learn an individual’s trait-like response to sleep loss and to provide personalized caffeine recommendations to optimize alertness. Methods We conducted a prospective 62-h total sleep deprivation study to validate the capabilities of 2B-Alert. Throughout the challenge, 21 participants used the app to measure their alertness via the psychomotor vigilance test (PVT). The app used the PVT data collected during the first 36 h of wakefulness to learn each participant’s sleep-loss response and provided on-the-fly personalized caffeine recommendations (from 0 to 800 mg), so that each participant would sustain alertness at a pre-specified target level (mean PVT response time of 270 ms) during a 6-h period starting at 44 h into the challenge. To assess the effectiveness of the personalized recommendations, we computed the amount of PVT data during the 6-h period that fell within the target alertness level +/-2 times the within-subject variability of alertness impairment (i.e., +/-60 ms). Results We observed a wide range of responses to sleep loss, with some participants displaying high levels of resilience and others high levels of vulnerability. Accordingly, 2B-Alert recommended no caffeine to five participants, 100-400 mg to 11 participants, and 500-800 mg to five participants. Regardless of their sleep-loss response and the consumed amount of caffeine, participants sustained the target alertness level ~80% of the time during the 6-h period. Conclusion 2B-Alert automatically learns an individual’s trait-like response to sleep loss and provides personalized caffeine recommendations in real time so that individuals achieve a desired alertness level regardless of their susceptibility to sleep loss. Support (if any)

0619 Comparative analysis of different methods of assessing worker fatigue

Abstract Introduction Fatigue at work causes reduced functional capacity that is experienced during the workday, is associated with sleep deprivation and impairs decision making. Fatigue can be estimated in a self-reported way, through the Psychomotor Vigilance Test (PVT), postural balance and core body temperature (CBT) that correlate with performance. Interest in fatigue assessment should focus on identifying risk conditions. Thus, the objective of the study is to present comparative results of 4 different methods used to estimate fatigue. Methods This study was approved by Research Ethics Committee (protocol CAAE nº 97394818.6.0000.5149). The sample consisted of 47 volunteers, who worked as truck operators, in a fast reverse rotational shift (4x1) with a workload for each shift of 6 hours, including a 12-hour break between shifts. All workers were submitted to fatigue assessment by postural sway using the Sonômetro for 15 days, in addition to assessments for 5 days such as CBT monitoring, 5 minutes of PVT and karolinska sleepiness scale (KSS). The gamma distribution with the identity function was considered for data analysis through the method of generalized linear models. Results CBT measurements were compared from the first to the sixth hour between shifts, no significant differences were observed . Of the variables evaluated by PVT, only the 10% faster presented worse results in the night shift (00:00 to 06:00). The KSS showed no differences between the evaluated times. The result of the pairwise comparisons indicated that there are differences in postural sway by SONOMETRO, being greater at the beginning of the shift 00:00 to 06:00, in relation to the shift 12:00 to 18:00. In the middle and at the end of the shift, a difference was found between the shift 00:00 to 06:00 and all others. Conclusion Among the presented methods, the SONOMETER and a single variable of PVT (10% faster), identified differences in the levels of fatigue. It is up to managers to identify the method that best suits the objective of the assessment, as well as the local culture and conditions. Thus, the combined use of different risk and fatigue assessment and management methods may favor the identification and management of worker fatigue. Support (if any)

0168 The Role of Alertness (vs. Fatigue) in the Performance of Professional Criminal Investigators

Abstract Introduction Investigative interviews and interrogations are a critical component of official inquiries. However, how levels of alertness (vs. fatigue) of the interviewer impact performance during investigative interviews or their outcomes is unclear. To this end, the current effort aimed to estimate the impact of objectively estimated alertness on (1) deception detection across true and false alibi statements and (2) outcomes of real-life investigative interviews conducted by officers in the field. Methods To achieve the first goal, sets of 8 video-recorded alibi statements (each from a different individual, with half being true) were presented to 26 law-enforcement professionals (average age of 42, two-thirds male). Prior to judging the alibi statements on truthfulness, they completed the 5-min Psychomotor Vigilance Test and rated their sleepiness. To achieve the second goal, another study tracked daily fluctuations in alertness among investigators to predict their experiences with actual field interviews. Fifty law-enforcement investigators (mean age 42, 75% male) wore a sleep-activity tracker (Readiband) for two weeks while keeping a daily-diary of interviews conducted in the field. For each interview, the investigators indicated (a) how well they established rapport with the subject, (b) how much resistance they encountered, (c) how well they maintained their own focus and composure, and (d) the overall utility of evidence obtained. Readiband-generated estimates of daily fatigue were used to predict daily interview outcomes. Results First, when judging alibis’ credibility, officer’s alertness was a strong predictor of lie-detection performance. Specifically, officers who were better at detecting deception across alibi statements were more objectively alert, indicated by faster reaction times (r = .52) and fewer attentional lapses (r = -.67). This better detection performance was largely accounted by stronger skepticism of actual lies. Second, Investigators from the field-interviewing study consistently reported more difficulties maintaining their focus and composure during interviews on days with lower alertness, as well as indicated more subject resistance and less rapport. Conclusion The findings suggest fatigue among criminal investigators (and underlying sleep disruption) is an important factor for how actual law-enforcement field interviews unfold. The findings implicate adequate sleep as a modifiable fitness factor for criminal investigators. Support (if any) Federal Bureau of Investigation Contract #15F06718C000253

0190 Propensity for Sleep Inertia during Sleep and Its Manifestation After Awakening in a Dynamic Biomathematical Fatigue Model

Abstract Introduction Sleep inertia, the transient period of cognitive impairment experienced immediately after awakening, is of concern in on-call and around-the-clock operational settings and merits development of a predictive tool to manage the associated fatigue risk. Recent work on our previously published biomathematical fatigue model revealed that predictive information about sleep inertia can be gained from tracking the propensity for sleep inertia across time spent asleep. In this approach, a neurobiological process with relatively fast dynamics (in the order of several minutes) interacts with the much slower dynamics of circadian, homeostatic, and allostatic sleep/wake regulation. Here we refine our modeling approach by mathematically dissociating the magnitude of sleep inertia from its dissipation rate. Methods N=280 healthy young adults (ages 21–49y) each participated in one of four laboratory studies of total sleep deprivation, sustained sleep restriction, and/or daytime napping. At 2–4 hour intervals while awake, participants performed a Psychomotor Vigilance Test (PVT), assessing number of lapses (RT>500ms), and rated their sleepiness on the Karolinska Sleepiness Scale (KSS). Sleep periods were recorded polysomnographically. Data were divided into a calibration set used to estimate two new model parameters capturing sleep inertia, and a validation set used to independently verify model goodness-of-fit. Sleep inertia was modeled with two ordinary differential equations – one during wakefulness to track manifest impairment, and one during sleep to track the propensity for sleep inertia upon awakening. Two parameters were fit, one modulating sleep inertia magnitude and one providing a dynamic time constant. Results Based on the calibration data set, the sleep inertia dissipation half-life was found to be 0.43h±0.07h. Based on the validation data set, the goodness-of-fit root-mean-square-error was 2.56 for PVT and 1.05 for KSS, indicating moderate-to-high predictive accuracy. As an emergent property of the model, the propensity of sleep inertia first increased and then decreased over sleep time, peaking 1–2h into the sleep period. Conclusion A two-parameter expansion of our biomathematical fatigue model captured the transient effect of sleep inertia accurately for sleep deprivation, sleep restriction, and daytime napping scenarios, and revealed a novel, emerging dynamic of sleep inertia propensity during sleep. Support (if any) Federal Express Corporation and WSU HPC

0331 Effects of Cognitive Behavioral Therapy for Insomnia (CBTI) on Daytime Cognitive Functioning: A Report from the AIR Trial

Abstract Introduction Prior studies have shown that CBTI improves patient reported outcomes including daytime fatigue, mood status and quality of life, yet there are limited data concerning the effects of therapy on objective measures of daytime function. The current study tested the effects of CBTI on measures derived from the psychomotor vigilance test (PVT) in a sample of patients with comorbid insomnia disorder and sleep apnea. Methods Patients with insomnia and comorbid OSA, who were prescribed PAP therapy (N =155; Mage= 56.8±12.5 yrs.; 58.1% women) were randomized to digital CBTI (dCBTI) or Sleep Hygiene (CTRL). They completed PVT at baseline and after 8 weeks of treatment. Patients in the dCBTI arm who reached remission were offered no additional insomnia treatment, whereas those who did not were randomly assigned to 8 weeks of continued access to dCBTI or to a therapist delivered CBTI. Patients again completed the PVT after this second 8-week treatment phase. PVT outcome measures included mean reaction time, attentional lapses and efficiency scores. Linear mixed models were used to compare the PVT measures of patients receiving either of the CBTI treatment sequences with those assigned to the CTRL. Results Analyses showed significant group x time interactions for PVT attentional lapses (F = 3.04; p < .05) and for efficiency scores (F= 4.06; p< .025). Those who received either of the CBTI treatment sequences showed a greater reduction in attentional lapses and greater improvement in their efficiency scores from baseline to the post-treatment assessments than did those assigned the CTRL. Conclusion Findings indicate that CBTI improves objective indices of daytime cognitive functioning among those with comorbid apnea and insomnia disorder. Further tests of CBTI’s effects on these and other measures of cognitive functioning are warranted in other samples of insomnia patients who do and do not have medical, psychiatric and sleep disorder comorbidities. Support (if any) Funding support from the National Heart, Lung and Blood Institute, Grant # 1R01HL130559-01A1.

ISleepFirst: burnout, fatigue, and wearable-tracked sleep deprivation among residents staffing the medical intensive care unit.

This study aimed to evaluate the relationship between sleep, burnout, and psychomotor vigilance in residents working in the medical intensive care unit (ICU). A prospective cohort study of residents was implemented during a consecutive 4-week. Residents were recruited to wear a sleep tracker for 2weeks before and 2weeks during their medical ICU rotation. Data collected included wearable-tracked sleep minutes, Oldenburg burnout inventory (OBI) score, Epworth sleepiness scale (ESS), psychomotor vigilance testing, and American Academy of Sleep Medicine sleep diary. The primary outcome was sleep duration tracked by the wearable. The secondary outcomes were burnout, psychomotor vigilance (PVT), and perceived sleepiness. A total of 40 residents completed the study. The age range was 26-34years with 19 males. Total sleep minutes measured by the wearable decreased from 402min (95% CI: 377-427) before ICU to 389 (95% CI: 360-418) during ICU (p < 0.05). Residents overestimated sleep, logging 464min (95% CI: 452-476) before and 442 (95% CI: 430-454) during ICU. ESS scores increased from 5.93 (95% CI: 4.89, 7.07) to 8.33 (95% CI: 7.09,9.58) during ICU (p < 0.001). OBI scores increased from 34.5 (95% CI: 32.9-36.2) to 42.8 (95% CI: 40.7-45.0) (p < 0.001). PVT scores worsened with increased reaction time while on ICU rotation (348.5ms pre-ICU, 370.9ms post-ICU, p < 0.001). Resident ICU rotations are associated with decreased objective sleep and self-reported sleep. Residents overestimate sleep duration. Burnout and sleepiness increase and associated PVT scores worsen while working in the ICU. Institutions should ensure resident sleep and wellness checks during ICU rotation.

Basal forebrain parvalbumin neurons modulate vigilant attention and rescue deficits produced by sleep deprivation.

Attention is impaired in many neuropsychiatric disorders, as well as by sleep disruption, leading to decreased workplace productivity and increased risk of accidents. Thus, understanding the neural substrates is important. Here we test the hypothesis that basal forebrain neurons that contain the calcium-binding protein parvalbumin modulate vigilant attention in mice. Furthermore, we test whether increasing the activity of basal forebrain parvalbumin neurons can rescue the deleterious effects of sleep deprivation on vigilance. A lever release version of the rodent psychomotor vigilance test was used to assess vigilant attention. Brief and continuous low-power optogenetic excitation (1 s, 473 nm @ 5 mW) or inhibition (1 s, 530 nm @ 10 mW) of basal forebrain parvalbumin neurons was used to test the effect on attention, as measured by reaction time, under control conditions and following 8 hr of sleep deprivation by gentle handling. Optogenetic excitation of basal forebrain parvalbumin neurons that preceded the cue light signal by 0.5 s improved vigilant attention as indicated by quicker reaction times. By contrast, both sleep deprivation and optogenetic inhibition slowed reaction times. Importantly, basal forebrain parvalbumin excitation rescued the reaction time deficits in sleep-deprived mice. Control experiments using a progressive ratio operant task confirmed that optogenetic manipulation of basal forebrain parvalbumin neurons did not alter motivation. These findings reveal for the first time a role for basal forebrain parvalbumin neurons in attention, and show that increasing their activity can compensate for disruptive effects of sleep deprivation.

Safety and pharmacodynamics of a single infusion of danavorexton in adults with obstructive sleep apnea experiencing excessive daytime sleepiness despite adequate use of CPAP

BackgroundSleep disruptions experienced by patients with obstructive sleep apnea (OSA) can lead to excessive daytime sleepiness (EDS) and significantly impact patients’ quality of life. EDS may persist despite use of continuous positive airway pressure (CPAP) therapy. Small molecules that target the orexin system, which has a known role in sleep-wake regulation, show therapeutic potential for the treatment of EDS in patients with hypersomnia. This randomized, placebo-controlled, phase 1b study aimed to investigate the safety of danavorexton, a small-molecule orexin-2 receptor agonist, and its effects on residual EDS in patients with OSA. MethodsAdults with OSA aged 18–67 years with adequate CPAP use were randomized to one of six treatment sequences of single IV infusions of danavorexton 44 mg, danavorexton 112 mg, and placebo. Adverse events were monitored throughout the study. Pharmacodynamic assessments included maintenance of wakefulness test (MWT), Karolinska Sleepiness Scale (KSS), and the psychomotor vigilance test (PVT). Results and conclusionAmong 25 randomized patients, 16 (64.0%) had treatment-emergent adverse events (TEAEs) and 12 (48.0%) had TEAEs considered related to treatment, all mild or moderate. Seven patients (28.0%) had urinary TEAEs: three, seven, and none while taking danavorexton 44 mg, danavorexton 112 mg, and placebo, respectively. There were no deaths or TEAEs leading to discontinuation. Improvements in mean MWT, KSS, and PVT scores were observed with danavorexton 44 mg and 112 mg vs placebo. These findings show that danavorexton can improve subjective and objective measures of EDS in patients with OSA and residual EDS despite adequate CPAP use.

0175 Poor Association Between Subjective and Objective Sleepiness in Patients Evaluated in a Clinical Sleep Center

Abstract Introduction Sleepiness is a primary symptom among patients presenting at sleep clinics. Sleepiness is typically subjectively evaluated using the Epworth Sleepiness Scale (ESS), which has been associated with worse cardiovascular outcomes among sleep apnea patients. On the other hand, functional deficits due to sleepiness can be objectively quantified using a Psychomotor Vigilance Test (PVT). To better understand the presentation of “sleepiness”, we examined the relationship between subjective ESS and objective PVT among a clinical sample. We hypothesized that these two different measures of sleepiness would be correlated. Methods A prospective sample of patients being evaluated for sleep disorders in the Sleep Center at the University of Pennsylvania completed the ESS and PVT at the same clinical visit. Demographic data were obtained at the visit or derived from the electronic health record. Pearson’s linear correlations were utilized to examine the association between the ESS and both the transformed lapses (sum of square root of number of lapses and square root of lapses+1) and mean reciprocal response time (RRT) on the PVT. Results In total, 167 patients (98 [58.7%] males) were studied, with a mean (±SD) age of 54.7±16.8 years and BMI of 34.5±9.9 kg/m2. There were a similar number of White (67 [42.1%]) and Black (71 [44.7%]) participants and 129 (77.3%) had diagnosed or suspected obstructive sleep apnea (OSA). Patients had an average ESS of 8.1±5.4, and 10.5±10.6 lapses, 5.9±2.9 transformed lapses, and mean RRT of 3.4±0.7 seconds-1 on PVT. Among all patients, there was no statistically significant correlation between ESS and either transformed lapses (rho = 0.10, p=0.200) or mean RRT (rho = -0.10, p=0.201). Results were similar when comparing the two sleepiness measures restricted to patients with OSA. Conclusion Within patients being evaluated in a clinical sleep center, there was only a weak association between subjective sleepiness on the ESS and objective sleepiness on PVT. Thus, not all patients reporting daytime sleepiness have objective deficits, and vice versa. Results support using both assessments to fully characterize a patient’s sleepiness. Future studies should evaluate the relationship between adverse outcomes and subjective and objective sleepiness, alone and in combination. Support (if any)

Culturally tailored group Qigong exercise in older Chinese immigrants: A feasibility study

BackgroundCulturally tailored group exercise bridges health disparities among new immigrants, particularly older adults. We designed a Chinese Qigong (Baduanjin) exercise intervention testing the feasibility and acceptability among older Chinese at a senior daycare center in Philadelphia, PA, US. Methods10-week Qigong group in-person exercise was delivered 5 days a week, using a 12-minute video tutorial under trained research assistants’ guidance. Daily attendance and attrition was recorded. Participants completed baseline self-report assessments on physical and mental health, and two computerized cognitive tests, the psychomotor vigilance test and a memory test. Results53 older adults participated (mean age: 78, female: 88.7%). Average daily attendance was 65.28%. Stratification analysis on age groups <80 and ≥80 shows no significant differences on key variables. ConclusionsRecruitment for Baduanjin Qigong exercise was feasible in senior daycare centers, and older adults could easily learn and safely follow exercise movements. Preliminarily findings call for further research.

Assessing the impact of sleep restriction on the attention and executive functions of medical students: a prospective cohort study.

To compare the performance of medical students regarding attention and executive functions during a period of sleep restriction (insufficient sleep; period of classes) and a period of free sleep (sufficient sleep; vacation period). Sleep deprivation is associated with poor academic outcomes. Few studies have assessed the cognitive changes associated with sleep deprivation due to insufficient sleep syndrome in students and how they occur in real-life situations. This was a prospective cohort study. Medical students were assessed at two moments (class and vacation). The interval between assessments was 30days. The Pittsburgh Sleep Quality Index, the Consensus Sleep Diary, the Montreal Cognitive Assessment, the Psychomotor Vigilance Test (PVT) and the Wisconsin Sorting Cards Test were used. Forty-one students were assessed, 49% were female, with a median age of 21 (20; 23) years. There was a lower number of hours slept (5.75 (5.4; 7.0) vs 7.33 (6.0; 8.0) hours; p = 0.037), and a significantly poorer performance in the PVT (mean reaction time, p = 0.005; Minor lapses, p = 0.009) during the period of classes when compared to the vacation period. There was a correlation between the variation in hours of sleep of the two assessments and a variation in minor lapses in the two assessments (Ro: -0.395; p = 0.011; Spearman's correlation). Students had fewer hours of sleep and more reduced attention during the period of classes than during the vacation period. This decrease in sleeping hours was correlated with more impaired attention.

2B-Alert app 2.0: personalized caffeine recommendations for optimal alertness.

If properly consumed, caffeine can safely and effectively mitigate the effects of sleep loss on alertness. However, there are no tools to determine the amount and time to consume caffeine to maximize its effectiveness. Here, we extended the capabilities of the 2B-Alert app, a unique smartphone application that learns an individual's trait-like response to sleep loss, to provide personalized caffeine recommendations to optimize alertness. We prospectively validated 2B-Alert's capabilities in a 62-h total sleep deprivation study in which 21 participants used the app to measure their alertness throughout the study via the psychomotor vigilance test (PVT). Using PVT data collected during the first 36h of the sleep challenge, the app learned the participant's sleep-loss response and provided personalized caffeine recommendations so that each participant would sustain alertness at a pre-specified target level (mean response time of 270ms) during a 6-h period starting at 44h of wakefulness, using the least amount of caffeine possible. Starting at 42h, participants consumed 0 to 800mg of caffeine, per the app recommendation. 2B-Alert recommended no caffeine to five participants, 100-400mg to 11 participants, and 500-800mg to five participants. Regardless of the consumed amount, participants sustained the target alertness level ~80% of the time. 2B-Alert automatically learns an individual's phenotype and provides personalized caffeine recommendations in real time so that individuals achieve a desired alertness level regardless of their sleep-loss susceptibility.

Effect of homeostatic pressure on daytime vigilance performance: Evidence from behaviour and resting-state EEG.

Vigilance is highly sensitive to the time-of-day effect and goes through the daytime trough during the period of the post-noon dip. A midday nap could maintain individuals' vigilance at an optimal level. Thus, homeostatic sleep pressure is one of the main reasons for the post-noon dip in daytime vigilance. The current study focussed on the role of homeostatic sleep pressure in the diurnal variation of vigilance performance with normal circadian rhythms and the corresponding neural basis. With 34 healthy adults, we recorded the resting-state electroencephalogram activities and the following vigilance performance measured by psychomotor vigilance test in the morning, the no-nap mid afternoon, and the nap mid afternoon. The circadian process was controlled by measuring vigilance and resting-state electroencephalogram activities at the same time point in the nap and no-nap conditions. Homeostatic sleep pressure accumulated from morning to mid afternoon induced the declined vigilance performance and a global increase in resting-state delta, theta, alpha, and beta1 bands power, and a local increase in beta2 band power in the central region. Furthermore, the more the spontaneous beta2 power increased, the less vigilance declined from morning to mid afternoon. The current findings suggest that homeostatic sleep pressure increased cortical excitability but decreased cortical communication efficiency from morning to mid afternoon. In addition, the activity of the high beta waves probably reflected the compensatory effort to counteract the negative impact of the low arousal state on the following vigilance task by performing more action preparation in the no-nap afternoon.

Effect of video gaming on some central auditory processing abilities in school aged children, cross sectional study

Objectives The effect of video games playing was variable in the literature. On one hand, it leads to boosting brain function in response speed, concentration, attention and spatial cognition, on the other hand, a certain type of games have negative effects on the cognition and proper processing of the central nervous system. In The best of the authors knowledge, there is no study investigated the effects of video gaming on central auditory processing in school-aged children, so the objective of this work is to study the effect of video gaming on some central auditory processing abilities in school-aged children. Methods 50 children aged 6–12 years old, playing video games > 2 h/d, were subjected to psychometric, basic audiological evaluation, history of mobile phone use and Central Auditory Processing (CAP) Disorders. CAP evaluation included; Speech Intelligibility In Noise (SPIN), Arabic Dichotic Digits (DD), Memory and Auditory Vigilance tests. Results The highest percentage of abnormality in CAP abilities was in selective attention ability followed by sequential memory besides the negative correlation with duration (hours) of video gaming use per day. Conclusion Video gaming has a negative impact on CAP abilities in children, particularly auditory attention and memory.

Nocturnal sodium oxybate increases the anterior cingulate cortex magnetic resonance glutamate signal upon awakening.

Clinical guidelines recommend sodium oxybate (SXB; the sodium salt of γ-hydroxybutyrate) for the treatment of disturbed sleep and excessive daytime sleepiness in narcolepsy, yet the underlying mode of action is elusive. In a randomised controlled trial in 20 healthy volunteers, we aimed at establishing neurochemical changes in the anterior cingulate cortex (ACC) following SXB-enhanced sleep. The ACC is a core neural hub regulating vigilance in humans. At 2:30 a.m., we administered in a double-blind cross-over manner an oral dose of 50 mg/kg SXB or placebo, to enhance electroencephalography-defined sleep intensity in the second half of nocturnal sleep (11:00 p.m. to 7:00 a.m.). Upon scheduled awakening, we assessed subjective sleepiness, tiredness and mood and measured two-dimensional, J-resolved, point-resolved magnetic resonance spectroscopy (PRESS) localisation at 3-Tesla field strength. Following brain scanning, we used validated tools to quantify psychomotor vigilance test (PVT) performance and executive functioning. We analysed the data with independent t tests, false discovery rate (FDR) corrected for multiple comparisons. The morning glutamate signal (at 8:30 a.m.) in the ACC was specifically increased after SXB-enhanced sleep in all participants in whom good-quality spectroscopy data were available (n=16; pFDR < 0.002). Further, global vigilance (10th-90th inter-percentile range on the PVT) was improved (pFDR < 0.04) and median PVT response time was shorter (pFDR < 0.04) compared to placebo. The data indicate that elevated glutamate in the ACC could provide a neurochemical mechanism underlying SXB's pro-vigilant efficacy in disorders of hypersomnolence.

Feigning Adult ADHD on a Comprehensive Neuropsychological Test Battery: An Analogue Study

The evaluation of performance validity is an essential part of any neuropsychological evaluation. Validity indicators embedded in routine neuropsychological tests offer a time-efficient option for sampling performance validity throughout the assessment while reducing vulnerability to coaching. By administering a comprehensive neuropsychological test battery to 57 adults with ADHD, 60 neurotypical controls, and 151 instructed simulators, we examined each test's utility in detecting noncredible performance. Cut-off scores were derived for all available outcome variables. Although all ensured at least 90% specificity in the ADHD Group, sensitivity differed significantly between tests, ranging from 0% to 64.9%. Tests of selective attention, vigilance, and inhibition were most useful in detecting the instructed simulation of adult ADHD, whereas figural fluency and task switching lacked sensitivity. Five or more test variables demonstrating results in the second to fourth percentile were rare among cases of genuine adult ADHD but identified approximately 58% of instructed simulators.

Metabolomics-based Sleepiness Markers for Risk Prevention and Traffic Safety (ME-SMART): a monocentric, controlled, randomized, crossover trial

BackgroundToo little sleep and the consequences thereof are a heavy burden in modern societies. In contrast to alcohol or illicit drug use, there are no quick roadside or workplace tests for objective biomarkers for sleepiness. We hypothesize that changes in physiological functions (such as sleep–wake regulation) are reflected in changes of endogenous metabolism and should therefore be detectable as a change in metabolic profiles. This study will allow for creating a reliable and objective panel of candidate biomarkers being indicative for sleepiness and its behavioral outcomes.MethodsThis is a monocentric, controlled, randomized, crossover, clinical study to detect potential biomarkers. Each of the anticipated 24 participants will be allocated in randomized order to each of the three study arms (control, sleep restriction, and sleep deprivation). These only differ in the amount of hours slept per night. In the control condition, participants will adhere to a 16/8 h wake/sleep regime. In both sleep restriction and sleep deprivation conditions, participants will accumulate a total sleep deficit of 8 h, achieved by different wake/sleep regimes that simulate real-life scenarios. The primary outcome is changes in the metabolic profile (i.e., metabolome) in oral fluid. Secondary outcome measures will include driving performance, psychomotor vigilance test, d2 Test of Attention, visual attention test, subjective (situational) sleepiness, electroencephalographic changes, behavioral markers of sleepiness, changes in metabolite concentrations in exhaled breath and finger sweat, and correlation of metabolic changes among biological matrices.DiscussionThis is the first trial of its kind that investigates complete metabolic profiles combined with performance monitoring in humans over a multi-day period involving different sleep–wake schedules. Hereby, we aim to establish a candidate biomarker panel being indicative for sleepiness and its behavioral outcomes. To date, there are no robust and easily accessible biomarkers for the detection of sleepiness, even though the vast damage on society is well known. Thus, our findings will be of high value for many related disciplines.Trial registrationClinicalTrials.gov Identifier NCT05585515, released on 18.10.2022; Swiss National Clinical Trial Portal SNCTP000005089, registered on 12 August 2022.

Correction to: Alert at Work? Perceptions of Alertness Testing and Recommendations for Practitioners

Correction to: Alert at Work? Perceptions of Alertness Testing and Recommendations for Practitioners