Time of day can alter memory performance in general. Its influence on memory recognition performance for faces, which is important for daily encounters with new persons or testimonies, has not been investigated yet. Importantly, high levels of the stress hormone cortisol impair memory recognition, in particular for emotional material. However, some studies also reported high cortisol levels to enhance memory recognition. Since cortisol levels in the morning are usually higher than in the evening, time of day might also influence recognition performance. In this pre-registered study with a two-day design, 51 healthy men encoded pictures of male and female faces with distinct emotional expressions on day one around noon. Memory for the faces was retrieved two days later at two consecutive testing times either in the morning (high and moderately increased endogenous cortisol levels) or in the evening (low endogenous cortisol levels). Additionally, alertness as well as salivary cortisol levels at the different timepoints was assessed. Cortisol levels were significantly higher in the morning compared to the evening group as expected, while both groups did not differ in alertness. Familiarity ratings for female stimuli were significantly better when participants were tested during moderately increased endogenous cortisol levels in the morning than during low endogenous cortisol levels in the evening, a pattern which was previously also observed for stressed versus non-stressed participants. In addition, cortisol levels during that time in the morning were positively correlated with the recollection of face stimuli in general. Thus, recognition memory performance may depend on the time of day and as well as on stimulus type, such as the difference of male and female faces. Most importantly, the results suggest that cortisol may be meaningful and worth investigating when studying the effects of time of day on memory performance. This research offers both, insights into daily encounters as well as legally relevant domains as for instance testimonies.

Objective To investigate the effects of Schisandrae Chinensis Fructus lignans on the alertness of the rats with sleep deprived by treadmill exercise and the underlying neurobiological mechanism. Methods According to the random number table method,SD male rats were assigned into control,sleep deprivation,low-,medium-,and high-dose Schisandrae Chinensis Fructus lignans,and atomoxetine hydrochloride groups,with 8 rats in each group.The rats in other groups except the control group were subjected to sleep deprivation by treadmill exercise for 3 d.During the deprivation period,each administration group was administrated with the corresponding drug by gavage,and a 5-9 hole tester was used to test the alertness performance of rats in each group. Furthermore,other SD male rats were selected and randomized into control,sleep deprivation,Schisandrae Chinensis Fructus lignans (67.2 mg/kg) and atomoxetine hydrochloride groups,with 10 rats in each group.The rats were modeled with the sleep deprivation method the same as that above and administrated with corresponding agents.ELISA was employed to measure the serum level of orexin A in each group of rats.The protein levels of c-Fos,orexin receptor 1,and orexin receptor 2 in the prefrontal cortex of rats in each group were observed by immunofluorescence and Western blotting. Results Compared with the control group,sleep deprivation reduced the choice accuracy (P<0.001) and increased the omission responses,omission percent,and mean correct response latency (P=0.002,P=0.003,P=0.020).Compared with the sleep deprivation group,medium- and high-dose Schisandrae Chinensis Fructus lignans and atomoxetine hydrochloride improved the alertness of rats,as demonstrated by the increased choice accuracy (P=0.001,P=0.006,P<0.001) and reduced omission responses (P=0.001,P=0.001,P<0.001),omission percent (P=0.001,P=0.002,P<0.001),and mean correct response latency (P=0.018,P=0.003,P=0.014).Compared with the control group,the sleep deprivation group showed elevated level of orexin A in the serum (P<0.001),up-regulated expression of c-Fos (P<0.001),and down-regulated expression of orexin receptor 1 (P=0.037) in the prefrontal cortex.Compared with the sleep deprivation group,Schisandrae Chinensis Fructus lignans (67.2 mg/kg) and atomoxetine hydrochloride lowered the orexin A level in the serum (P=0.005,P=0.029),down-regulated the expression of c-Fos (P=0.028,P=0.036),and up-regulated the expression of orexin receptor 1 (P=0.043,P=0.013) in the prefrontal cortex. Conclusion Schisandrae Chinensis Fructus lignans may antagonize the alertness decrease caused by sleep deprivation by regulating the secretion of orexin and the expression of orexin receptor 1 in the prefrontal cortex.
目的 探讨五味子木脂素对跑步机睡眠剥夺大鼠警觉性水平的影响及其可能的神经生物学机制。方法 SD雄性大鼠,随机数字表法分为空白组,睡眠剥夺组,五味子木脂素低、中、高剂量组,盐酸托莫西汀组,每组8只。除空白组外,其他各组大鼠均进行跑步机睡眠剥夺,连续3 d。剥夺期间,各个给药组分别灌胃给予相应药物,采用5~9孔测试仪测试各组大鼠的警觉性表现;另取SD雄性大鼠,睡眠剥夺方法造模和给药方法同上,随机数字表法分为空白组、睡眠剥夺组、五味子木脂素组(67.2 mg/kg)和盐酸托莫西汀组,每组10只,采用ELISA技术测定各组大鼠血清中食欲素A的含量;采用免疫荧光、Western blot法观察各组大鼠前额叶皮层(PFC)c-Fos蛋白表达和食欲素受体 1、2水平的变化。结果 与空白组相比,睡眠剥夺组大鼠警觉性表现的选择准确性显著降低(P<0.001),遗漏反应、遗漏率和平均反应潜伏期均显著升高(P=0.002,P=0.003,P=0.020);与睡眠剥夺组相比,五味子木脂素中、高剂量组和盐酸托莫西汀组均可改善跑步机睡眠剥夺大鼠的警觉性指标,表现为选择准确性提高(P=0.001,P=0.006,P<0.001),遗漏反应(P=0.001,P=0.001,P<0.001)、遗漏率(P=0.001,P=0.002,P<0.001)和平均反应潜伏期(P=0.018,P=0.003,P=0.014)减少。与空白组相比,睡眠剥夺组大鼠血清中的食欲素 A含量、PFC脑区c-Fos均显著增加(P均<0.001),食欲素受体1蛋白表达水平显著减少(P=0.037);与睡眠剥夺组相比,五味子木脂素组(67.2 mg/kg)和盐酸托莫西汀组大鼠血清中的食欲素 A水平(P=0.005,P=0.029)、PFC脑区c-Fos(P=0.028,P=0.036)均显著降低,食欲素受体1蛋白表达水平显著升高(P=0.043,P=0.013)。结论 五味子木脂素可能通过调节食欲素分泌和PFC的食欲素受体1表达发挥拮抗睡眠剥夺所致警觉性水平下降的作用。.

Background and objectives Stadice® is a proprietary herbal ingredient preparation standardized to mangiferin, developed to support cognitive wellness in healthy adults. Mangifera indica extract and its active constituent, mangiferin were known for its positive cognitive health benefits at experimental levels. This was an attempt to evaluate the clinical efficacy and safety of Stadice® on healthy subjects. Materials and methods A randomized, double-blind, placebo-controlled clinical study was designed to study the efficacy and safety of Stadice®. Sixty healthy subjects who were regularly playing virtual/mobile/computer/laptop games online or offline were asked to consume a capsule containing 300 mg of Stadice® or placebo per day for seven days. Cognitive ability tests, that were part of the NIMHANS Neuropsychological Battery and Auditory verbal learning tests were used to assess the cognitive health effects. Psychological stress response, anxiety, mood, subjective working memory, and cortisol levels were also assessed. All assessments were carried out at the baseline and at the end of the study. Results Stadice® was found to significantly improve mental speed, attention, working memory, response inhibition, and verbal learning and memory as evidenced by the results of the multiple cognitive ability tests. Additionally, Stadice ® showed beneficial responses in managing psychological stress in terms of handling nervousness, irritability, or mood swings. No safety concerns were found in the laboratory safety test parameters as they were within the normal physiological range and no adverse events were reported in this study. Conclusion The proprietary Mangifera indica extract (Stadice®) holds promise for enhancing cognitive abilities in healthy adults, particularly those engaged in esports. Improvements in learning, memory, mental speed, attention, response inhibition, and working memory among participants supplemented with Stadice® were observed with a good safety profile. Further exploration is warranted to ascertain its broader applicability as well as to elucidate the possible mechanisms.

OBJECTIVE: Sleepiness in patients with obstructive sleep apnea (OSA) is associated with accidental and economic burden, as well as cardiovascular risk. Despite OSA treatment, 10-28 % of patients report residual sleepiness. Its determinants, as well as those of objective impaired alertness remain poorly known. In this study, we investigated factors associated with residual subjective sleepiness and objective impaired alertness in patients treated for OSA.
METHODS: Consecutive OSA treated patients referred for maintenance of wakefulness tests (MWT) at a tertiary university center were recruited between 2017 and 2020. Clinical data and polysomnography parameters were compared between patients with vs without subjective sleepiness (Epworth Sleepiness Scale, ESS≥11) and those with vs without impaired alertness (at least one trial with sleep onset on MWT). A multivariate logistic model was used to assess explanatory variables of MWT and ESS results.
RESULTS: We included 141 patients, of whom 12.8 % had both subjective sleepiness and objective impaired alertness, 17.7 % objective impaired alertness only and 9.2 % subjective sleepiness only. Self-reported history of car accident/near miss, smoking history and ESS≥11 were significantly associated with objective impaired alertness whereas residual Apnea-hypopnea Index and CPAP use were not. The only significant variable associated with ESS at the time of MWT evaluation was initial ESS. Patients with objective impaired alertness only were more often smokers (52 % vs 19 %, p = 0.01), had a higher body mass index (BMI) (32 vs 29 kg/m2, p = 0.05), and showed lower initial ESS (11 vs 13, p < 0.01).
CONCLUSIONS: More than one third of OSA treated patients referred for MWT have objective impaired alertness and/or subjective sleepiness. Our findings highlight the need for a comprehensive medical assessment including accident history, subjective sleepiness and comorbidities. Particular attention should be paid to smoking patients with high BMI, who are at risk of impaired alertness with no report of subjective sleepiness.

UNASSIGNED: Exposure to artificial light influences human performance, which is essential for maintaining healthy work and sleep. However, existing research has not explored the intrinsic links between sleep performance and human states over time under prebedtime light exposure interventions (LEIs).
UNASSIGNED: To investigate the time-dependent effects of altered prebedtime light exposure, four LEI groupings (#L1 - #L4) and a Time factor (D8, D9, and D10) were chosen for sleep experiments in enclosed spaces. Forty-eight young adults recruited were available for data analysis. Subjective alertness (SA), negative affect (NA), subjective sleep, and objective sleep were measured via the Karolinska Sleepiness Scale, Positive and Negative Affect Schedule, Next-day Self-assessment Sleep Quality, and joint assessment of wrist actigraphy and sleep diaries, respectively. Statistical analysis was used for the effects of light exposure on the human states (corresponding to the SA and NA) and sleep performance, while the process model helped construct the associations between the two.
UNASSIGNED: The statistical effects revealed that the Time had a significant main effect on subjective sleep and changes in prebedtime alertness; the LEI had a significant main effect only on sleep onset latency (SOL). After undergoing altered prebedtime light exposure, the mean SA increased at prebedtime of D9 (p = 0.022) and D10 (p = 0.044); No significant effect on the NA was observed; Mean subjective sleep had a significant increase from D8 to D10. Moreover, five actigraphy-estimated sleep parameters were interrelated. In light of this, a chained pathway relationship was identified. The SOL played a mediating predictor between prebedtime state and objective sleep, which was linked to the awakening state through subjective sleep.
UNASSIGNED: Our study suggests that time-dependent effects of altered prebedtime light exposure on sleep performance are associated with human states at prebedtime and awakening, with implications for its prediction of sleep health.

Background: Human circadian clocks are synchronized daily with the external light-dark cycle and entrained to the 24-hour day. There is increasing evidence that a lack of synchronization and circadian entrainment can lead to adverse health effects. Beyond vision, light plays a critical role in modulating many so-called non-visual functions, including sleep-wake cycles, alertness, mood and endocrine functions. To assess (and potentially optimize) the impact of light on non-visual functions, it is necessary to know the exact \'dose\' (i.e. spectral irradiance and exposure duration at eye level) of 24-hour light exposures, but also to include metadata about the lighting environment, individual needs and resources.
Problem statement: To address this problem, a new assessment tool is needed that uses existing metrics to provide metadata and information about light quality and quantity from all sources. In this commentary, we discuss the need to develop an evidence-based integrative lighting score that is tailored to specific audiences and lighting environments. We will summarize the most compelling evidence from the literature and outline a future plan for developing such a lighting score using internationally accepted metrics, stakeholder and user feedback.
Conclusion: We propose a weighting system that combines light qualities with physiological and behavioral effects, and the use of mathematical modelling for an output score. Such a scoring system will facilitate a holistic assessment of a lighting environment, integrating all available light sources.
To assess the impact of light on non-visual functions, it is essential to know the exact ‘dose’ of 24-hour light exposures and metadata about the lighting environment and the individual.There is to date no measurement method available that allows a holistic assessment of a lighting environment for visual and non-visual aspects in humans.We discuss the need for an evidence-based integrative lighting score and outline a plan for its development.An evidence-based integrative lighting score, which includes a weighting system to combine light qualities with physiological and behavioral effects, will only be possible by joining forces, knowledge, and methodologies from many disciplines.Such a score entails the potential to sustainably assess, improve and maintain optimized lighting environments that promote the health and productivity of any cohort over the long term.

Improving fatigue management is critical to the occupational safety of professional drivers. We aimed to identify the factors that facilitated or hindered the implementation of digital sleep coaching in bus companies and to explore bus drivers\' experiences with it. Two bus companies implemented coaching for bus drivers. Using a mixed methods design, we collected data through two workshops (n = 30 and n = 27) attended by key personnel from the organisations and through questionnaires to the drivers (n = 30). Implementation was facilitated by, for example, the flexible participation and multichannel information of coaching, and hindered by restrictions on social support due to the COVID-19 pandemic, and lack of interest and inspiring examples. On average, the drivers rated the appropriateness and the feasibility of coaching as good. However, further development could lead to wider dissemination. It would also be important to involve the key people in the organisations and stakeholders more in supporting the implementation.

UNASSIGNED: Fatigue poses risks to occupational health and safety, affecting individuals\' work efficiency, physical health, and social security, as well as human wellbeing and quality of life. Olfactory interventions, due to their low interference, are considered promising strategies for mitigating fatigue and reducing occupational health hazards.
UNASSIGNED: The objective of this review is to bridge the current gaps in the literature by conducting a scoping review of olfactory interventions on human alertness. It aims to explore their application in various occupational settings and to provide comprehensive and practical guidance for the practical application of olfactory interventions in mitigating fatigue and reducing occupational risks.
UNASSIGNED: The literature research was conducted in English using electronic databases such as Web of Science. Keywords related to scent and fatigue and the review followed PRISMA Extension for Scoping Reviews and PICO framework.
UNASSIGNED: 28 studies were included in this work. Participant characteristics, fatigue measurement methods, and scent intervention methods, such as types of scents, intervention strategies, and scent presentation systems, are thoroughly investigated and discussed. Additionally, the study places a specific emphasis on the applications and research within the field of scent interventions for fatigue driving. Olfactory interventions have been applied to populations in various occupational fields, demonstrating beneficial effects on both physiological and psychological fatigue.
UNASSIGNED: Olfactory intervention is effective and promising for enhancing alertness and improving the occupational environment. To provide detailed and practical guidance for the actual application of olfactory intervention in fatigue relief and reducing occupational health and safety hazards, further research into the potential mechanisms, applications, and efficacy assessment systems of fatigue-related olfactory interventions is necessary.

Light regulates both image- and various non-image forming responses in humans, including acute effects on attention and affect. To advance the understanding of light\'s immediate effects, this systematic review describes the acute effects of monochromatic/narrow bandwidth and polychromatic white light during daytime on distinct aspects of attention (alertness, sustained attention, working memory, attentional control and flexibility), and measures of affect (self-report measures, performance-based tests, psychophysiological measures) in healthy, adult human subjects. Original, peer-reviewed (quasi-) experimental studies published between 2000 and May 2024 were included according to predefined inclusion and exclusion criteria. Study quality was assessed, and results were synthesized across aspects of attention and affect and grouped according to light interventions; monochromatic/narrowband-width or polychromatic white light (regular white, bright white, and white with high correlated color temperature (CCT)). Results from included studies (n = 62) showed that alertness and working memory were most affected by light. Electroencephalographic markers of alertness improved the most with exposure to narrow bandwidth long-wavelength light, regular white, and white light with high CCT. Self-reported alertness and measures of working memory improved the most with bright white light. Results from studies testing the acute effects on sustained attention and attentional control and flexibility were inconclusive. Performance-based and psychophysiological measures of affect were only influenced by narrow bandwidth long-wavelength light. Polychromatic white light exerted mixed effects on self-reported affect. Studies were strongly heterogeneous in terms of light stimuli characteristics and reporting of light stimuli and control of variables influencing light\'s acute effects.

OBJECTIVE: Sleep loss can cause cognitive impairments that increase the risk of mistakes and accidents. However, existing guidelines to counteract the effects of sleep loss are generic and are not designed to address individual-specific conditions, leading to sub-optimal alertness levels. Here, we developed an optimization algorithm that automatically identifies sleep schedules and caffeine-dosing strategies to minimize alertness impairment due to sleep loss for desired times of the day.
METHODS: We combined our previous algorithms that separately optimize sleep or caffeine to simultaneously identify the best sleep schedules and caffeine doses that minimize alertness impairment at desired times. The optimization algorithm uses the predictions of the well-validated Unified Model of Performance to estimate the effectiveness and physiological feasibility of a large number of possible solutions and identify the best one. To assess the optimization algorithm, we used it to identify the best sleep schedules and caffeine-dosing strategies for four studies that exemplify common sleep-loss conditions and compared the predicted alertness-impairment reduction achieved by using the algorithm\'s recommendations against that achieved by following the U.S. Army caffeine guidelines.
RESULTS: Compared to the alertness-impairment levels in the original studies, the algorithm\'s recommendations reduced alertness impairment on average by 63%, an improvement of 24 percentage points over the U.S. Army caffeine guidelines.
CONCLUSIONS: We provide an optimization algorithm that simultaneously identifies effective and safe sleep schedules and caffeine-dosing strategies to minimize alertness impairment at user-specified times.