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Stefani O, Schöllhorn I, Münch M. Towards an evidence-based integrative lighting score: a proposed multi-level approach. Ann Med 2024; 56:2381220. [PMID: 39049780 PMCID: PMC11275531 DOI: 10.1080/07853890.2024.2381220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 03/01/2024] [Accepted: 03/01/2024] [Indexed: 07/27/2024] Open
Abstract
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.
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Affiliation(s)
- Oliver Stefani
- Lucerne School of Engineering and Architecture, Lucerne University of Applied Sciences and Arts, Horw, Switzerland
| | - Isabel Schöllhorn
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
| | - Mirjam Münch
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Research Cluster Molecular Cognitive Neuroscience, University of Basel, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
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2
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Bjerrum LB, Nordhus IH, Sørensen L, Wulff K, Bjorvatn B, Flo-Groeneboom E, Visted E. Acute effects of light during daytime on central aspects of attention and affect: A systematic review. Biol Psychol 2024; 192:108845. [PMID: 38981576 DOI: 10.1016/j.biopsycho.2024.108845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 06/29/2024] [Accepted: 07/02/2024] [Indexed: 07/11/2024]
Abstract
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.
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Affiliation(s)
| | | | - Lin Sørensen
- Department of Biological and Medical Psychology, University of Bergen, Norway
| | - Katharina Wulff
- Department of Molecular Biology, Umeå University, Sweden; Wallenberg Centre for Molecular Medicine, Umeå University, Sweden
| | - Bjørn Bjorvatn
- Department of Global Public Health and Primary Care, University of Bergen, Norway; Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Norway
| | | | - Endre Visted
- Department of Clinical Psychology, University of Bergen, Norway
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3
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Didikoglu A, Mohammadian N, Johnson S, van Tongeren M, Wright P, Casson AJ, Brown TM, Lucas RJ. Associations between light exposure and sleep timing and sleepiness while awake in a sample of UK adults in everyday life. Proc Natl Acad Sci U S A 2023; 120:e2301608120. [PMID: 37812713 PMCID: PMC10589638 DOI: 10.1073/pnas.2301608120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 08/11/2023] [Indexed: 10/11/2023] Open
Abstract
Experimental and interventional studies show that light can regulate sleep timing and sleepiness while awake by setting the phase of circadian rhythms and supporting alertness. The extent to which differences in light exposure explain variations in sleep and sleepiness within and between individuals in everyday life remains less clear. Here, we establish a method to address this deficit, incorporating an open-source wearable wrist-worn light logger (SpectraWear) and smartphone-based online data collection. We use it to simultaneously record longitudinal light exposure (in melanopic equivalent daylight illuminance), sleep timing, and subjective alertness over seven days in a convenience sample of 59 UK adults without externally imposed circadian challenge (e.g., shift work or jetlag). Participants reliably had strong daily rhythms in light exposure but frequently were exposed to less light during the daytime and more light in pre-bedtime and sleep episodes than recommended [T. M. Brown et al., PLoS Biol. 20, e3001571 (2022)]. Prior light exposure over several hours was associated with lower subjective sleepiness with, in particular, brighter light in the late sleep episode and after wake linked to reduced early morning sleepiness (sleep inertia). Higher pre-bedtime light exposure was associated with longer sleep onset latency. Early sleep timing was correlated with more reproducible and robust daily patterns of light exposure and higher daytime/lower night-time light exposure. Our study establishes a method for collecting longitudinal sleep and health/performance data in everyday life and provides evidence of associations between light exposure and important determinants of sleep health and performance.
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Affiliation(s)
- Altug Didikoglu
- Centre for Biological Timing, Division of Neuroscience, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
- Department of Neuroscience, Izmir Institute of Technology, Gulbahce, Izmir35430, Turkey
| | - Navid Mohammadian
- Department of Electrical & Electronic Engineering, School of Engineering, Faculty of Science and Engineering, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Sheena Johnson
- Thomas Ashton Institute, People, Management and Organisation Division, Alliance Manchester Business School, Faculty of Humanities, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Martie van Tongeren
- Thomas Ashton Institute, Centre for Occupational and Environmental Health, Division of Population Health, Health Services Research & Primary Care, School of Health Sciences, Faculty of Biology Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Paul Wright
- Department of Electrical & Electronic Engineering, School of Engineering, Faculty of Science and Engineering, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Alexander J. Casson
- Department of Electrical & Electronic Engineering, School of Engineering, Faculty of Science and Engineering, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Timothy M. Brown
- Centre for Biological Timing, Division of Diabetes Endocrinology and Gastroenterology, School of Medical Sciences, Faculty of Biology Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Robert J. Lucas
- Centre for Biological Timing, Division of Neuroscience, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
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4
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Campbell I, Sharifpour R, Vandewalle G. Light as a Modulator of Non-Image-Forming Brain Functions—Positive and Negative Impacts of Increasing Light Availability. Clocks Sleep 2023; 5:116-140. [PMID: 36975552 PMCID: PMC10047820 DOI: 10.3390/clockssleep5010012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/17/2023] [Accepted: 03/13/2023] [Indexed: 03/19/2023] Open
Abstract
Light use is rising steeply, mainly because of the advent of light-emitting diode (LED) devices. LEDs are frequently blue-enriched light sources and may have different impacts on the non-image forming (NIF) system, which is maximally sensitive to blue-wavelength light. Most importantly, the timing of LED device use is widespread, leading to novel light exposure patterns on the NIF system. The goal of this narrative review is to discuss the multiple aspects that we think should be accounted for when attempting to predict how this situation will affect the NIF impact of light on brain functions. We first cover both the image-forming and NIF pathways of the brain. We then detail our current understanding of the impact of light on human cognition, sleep, alertness, and mood. Finally, we discuss questions concerning the adoption of LED lighting and screens, which offer new opportunities to improve well-being, but also raise concerns about increasing light exposure, which may be detrimental to health, particularly in the evening.
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Danilenko KV. Objective Measures of Immediate “Energizing” Effect of Light: Studies Review and Data Analysis. Clocks Sleep 2022; 4:475-496. [PMID: 36278531 PMCID: PMC9589941 DOI: 10.3390/clockssleep4040038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/18/2022] [Accepted: 09/20/2022] [Indexed: 11/16/2022] Open
Abstract
While the energizing effect of light has been known since the early years of light therapy, its reliable detection using objective measures is still not well-established. This review aims to ascertain the immediate energizing effect of light and determine its best indicators. Sixty-four articles published before July 2022 were included in the review. The articles described 72 (sub-)studies performed in healthy individuals. Fourteen measures were analyzed. The analysis showed that light causes an energizing effect that can be best documented by measuring core (rectal) body temperature: the proportion of the studies revealing increasing, unchanging, and decreasing rectal temperature was 13/6/1. The second most suitable indicator was heart rate (10/22/1), which showed concordant changes with rectal temperature (a trend, seven mutual studies). There is no evidence from the reviewed articles that oxygen consumption, skin conductance, blood pressure, heart rate variability, non-rectal inner temperature (combined digestive, tympanic, and oral), skin temperature, or cortisol levels can provide light effect detection. Four other measures were found to be unsuitable as well but with less certainty due to the low number of studies (≤3): skin blood flow, noradrenaline, salivary alpha-amylase, and thyroid-stimulating hormone levels. On the other hand, light exposure had a noticeable effect on sympathetic nerve activity measured using microneurography; however, this measure can be accepted as a marker only tentatively as it was employed in a single study. The analysis took into account three factors—study limitation in design/analysis, use of light in day- or nighttime, and relative brightness of the light stimulus—that were found to significantly influence some of the analyzed variables. The review indicates that the energizing effect of light in humans can be reliably detected using rectal temperature and heart rate.
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6
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Buchner L, Amesberger G, Finkenzeller T, Moore SR, Würth S. The modified German subjective vitality scale (SVS-GM): Psychometric properties and application in daily life. Front Psychol 2022; 13:948906. [PMID: 35967701 PMCID: PMC9374102 DOI: 10.3389/fpsyg.2022.948906] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/12/2022] [Indexed: 01/07/2023] Open
Abstract
Subjective vitality describes the positive feeling of experiencing physical and mental energy, which can lead to purposive actions, but no German instruments exist with action-oriented verbiage: This work supports the development and modification of already existing German Subjective Vitality Scales and provides further evidence for its psychometric properties. In a first step (N = 56) two modified (action-oriented) short-forms were developed. An extension of time perspectives (past, present, future) should also enrich the scale by enhancing the accuracy of self-reports. Study 1 (N = 183) then examined the psychometric properties for each time perspective. Study 2 (N = 27) was a 6-day diary study to identify the reliability of within- and between-person differences in vitality over time and working days with responses recorded three times per day. The exploratory factor analysis from study 1 revealed a three-factor solution with three items each. Test-retest reliability was moderate for the past and future time perspective and less stable for state subjective vitality. The modified German Subjective Vitality Scale (SVS-GM) showed divergent validity with fatigue, negative affect, and optimism, and convergent but distinguishable validity with life satisfaction, positive affect, and perceived self-efficacy. High reliability for daily vitality measures (with lower vitality rates in the morning) was found in study 2, but no substantial variation was found between working days and days off. The SVS-GM shows good psychometric properties in different settings and provides researchers with a 3-item (for cross-sectional or longitudinal studies) and 1-item (for short screenings) version to measure subjective vitality in German-speaking populations.
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7
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Ru T, Qian L, Chen Q, Sun H, Zhou G. Effects of an afternoon nap on sustained attention and working memory: The role of physiological arousal and sleep variables. Int J Psychophysiol 2022; 179:21-29. [PMID: 35753563 DOI: 10.1016/j.ijpsycho.2022.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 06/10/2022] [Accepted: 06/20/2022] [Indexed: 11/28/2022]
Abstract
Taking a short midday nap has been associated with higher alertness and better cognitive task performance. Yet, the mechanisms associated with nap-dependent performance enhancement are unclear. The current study was conducted to explore the impact of physiological arousal during cognitive task and sleep architecture during a pre-task nap on post-nap behavioral outcomes. A within-subjects design (N = 18) was employed, in which participants either took a nap or remained awake for 40 min during the post-lunch period. The psychomotor vigilance test (PVT) and n-back task were administered to assess sustained attention and working memory, respectively, with each task including one block of easy trials and one block of difficult trials. Results showed that a short midday nap improved sustained attention but not working memory. In addition, a midday nap induced lower physiological arousal during the performance on both cognitive tasks, with relatively higher delta and lower beta activity. The relative power of theta and alpha were positively correlated with performance on the easy PVT, whereas the alpha power was negatively correlated with performance on the difficult PVT, and the theta power was negatively correlated with reaction speed in the n-back task regardless of the task difficulty. Meanwhile, the shorter total sleep time and longer time of wake after sleep onset were associated with the faster overall reaction speed in PVT easy trials. These findings suggested that both changes in physiological arousal and sleep variables might account for changes in task performance after a short midday nap.
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Affiliation(s)
- Taotao Ru
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China; Lab of Light and Physio-psychological Health, School of Psychology, South China Normal University, Guangzhou 510631, China.
| | - Liu Qian
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China; Lab of Light and Physio-psychological Health, School of Psychology, South China Normal University, Guangzhou 510631, China
| | - Qingwei Chen
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China; Lab of Light and Physio-psychological Health, School of Psychology, South China Normal University, Guangzhou 510631, China
| | - Hailing Sun
- Lab of Light and Physio-psychological Health, School of Psychology, South China Normal University, Guangzhou 510631, China; Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Guofu Zhou
- Lab of Light and Physio-psychological Health, School of Psychology, South China Normal University, Guangzhou 510631, China; Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
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8
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Lok R, Joyce DS, Zeitzer JM. Impact of daytime spectral tuning on cognitive function. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 230:112439. [PMID: 35398657 DOI: 10.1016/j.jphotobiol.2022.112439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/22/2022] [Accepted: 03/25/2022] [Indexed: 06/14/2023]
Abstract
Light at night can improve alertness and cognition. Exposure to daytime light, however, has yielded less conclusive results. In addition to direct effects, daytime light may also mitigate the impact of nocturnal light exposure on alertness. To examine the impact of daytime lighting on daytime cognitive performance, and evening alertness, we studied nine healthy individuals using a within subject crossover design. On four visits, participants were exposed to one of four lighting conditions for 10 h (dim fluorescent, room fluorescent, broad-spectrum LED, standard white LED; the latter three conditions were matched for 100 lx) followed by an exposure to bright evening light. Cognitive performance, subjective and objective measures of alertness were regularly obtained. While daytime alertness was not impacted by light exposure, the broad-spectrum LED light improved several aspects of daytime cognition. The impact of evening light on alertness was not mitigated by the pre-exposure to different daytime lighting conditions. Results suggest that daytime exposure to white light with high melanopic efficacy has the potential to improve daytime cognitive function and that such improvements are likely to be direct rather than a consequence of light-induced changes in alertness.
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Affiliation(s)
- Renske Lok
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, United States of America
| | - Daniel S Joyce
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, United States of America; Department of Psychology, University of Nevada, Reno, Reno, NV 89557, United States of America
| | - Jamie M Zeitzer
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, United States of America; Mental Illness Research Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, CA 94304, United States of America.
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9
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Luo X, Ru T, Chen Q, Hsiao FC, Hung CS, Yang CM, Zhou G. Temporal Dynamics of Subjective and Objective Alertness During Exposure to Bright Light in the Afternoon for 5 h. Front Physiol 2021; 12:771605. [PMID: 34950050 PMCID: PMC8691749 DOI: 10.3389/fphys.2021.771605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/08/2021] [Indexed: 11/22/2022] Open
Abstract
Light can induce an alertness response in humans. The effects of exposure to bright light vs. dim light on the levels of alertness during the day, especially in the afternoon, as reported in the literature, are inconsistent. This study employed a multiple measurement strategy to explore the temporal variations in the effects of exposure to bright light vs. regular office light (1,200 lx vs. 200 lx at eye level, 6,500 K) on the alertness of participants for 5 h in the afternoon. In this study, 20 healthy adults (11 female; mean age 23.25 ± 2.3 years) underwent the Karolinska sleepiness scale (KSS), the auditory psychomotor vigilance test (PVT), and the waking electroencephalogram (EEG) test for two levels of light intervention. The results yielded a relatively lower relative delta power and a relatively higher beta power for the 1,200 lx condition in comparison with the 200 lx condition. However, the light conditions elicited no statistically significant differences in the KSS scores and performance with respect to the PVT. The results suggested that exposure to bright light for 5 h in the afternoon could enhance physiological arousal while exerting insignificant effects on subjective feelings and performance abilities relating to the alertness of the participants.
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Affiliation(s)
- Xue Luo
- School of Psychology, South China Normal University, Guangzhou, China
| | - Taotao Ru
- Lab of Light and Physiopsychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology and Institute of Electronic Paper Displays, South China Normal University, South China Academy of Advanced Optoelectronics, Guangzhou, China
| | - Qingwei Chen
- Lab of Light and Physiopsychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology and Institute of Electronic Paper Displays, South China Normal University, South China Academy of Advanced Optoelectronics, Guangzhou, China
| | - Fan-Chi Hsiao
- Department of Counseling and Industrial/Organizational Psychology, Ming Chuan University, Taoyuan, Taiwan
| | - Ching-Sui Hung
- Department of Psychology, National Chengchi University, Taipei, Taiwan
| | - Chien-Ming Yang
- Department of Psychology, National Chengchi University, Taipei, Taiwan.,The Research Center for Mind, Brain, and Learning, National Chengchi University, Taipei, Taiwan
| | - Guofu Zhou
- Lab of Light and Physiopsychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology and Institute of Electronic Paper Displays, South China Normal University, South China Academy of Advanced Optoelectronics, Guangzhou, China
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10
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Gurubhagavatula I, Barger LK, Barnes CM, Basner M, Boivin DB, Dawson D, Drake CL, Flynn-Evans EE, Mysliwiec V, Patterson PD, Reid KJ, Samuels C, Shattuck NL, Kazmi U, Carandang G, Heald JL, Van Dongen HP. Guiding principles for determining work shift duration and addressing the effects of work shift duration on performance, safety, and health: guidance from the American Academy of Sleep Medicine and the Sleep Research Society. J Clin Sleep Med 2021; 17:2283-2306. [PMID: 34666885 PMCID: PMC8636361 DOI: 10.5664/jcsm.9512] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 11/13/2022]
Abstract
CITATION Risks associated with fatigue that accumulates during work shifts have historically been managed through working time arrangements that specify fixed maximum durations of work shifts and minimum durations of time off. By themselves, such arrangements are not sufficient to curb risks to performance, safety, and health caused by misalignment between work schedules and the biological regulation of waking alertness and sleep. Science-based approaches for determining shift duration and mitigating associated risks, while addressing operational needs, require: (1) a recognition of the factors contributing to fatigue and fatigue-related risks; (2) an understanding of evidence-based countermeasures that may reduce fatigue and/or fatigue-related risks; and (3) an informed approach to selecting workplace-specific strategies for managing work hours. We propose a series of guiding principles to assist stakeholders with designing a shift duration decision-making process that effectively balances the need to meet operational demands with the need to manage fatigue-related risks.
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Affiliation(s)
- Indira Gurubhagavatula
- Division of Sleep Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Laura K. Barger
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Christopher M. Barnes
- Department of Management and Organization, Foster School of Business, University of Washington, Seattle, WA, USA
| | - Mathias Basner
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Diane B. Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Drew Dawson
- Appleton Institute, Central Queensland University, Wayville, SA, Australia
| | | | - Erin E. Flynn-Evans
- Fatigue Countermeasures Laboratory, NASA Ames Research Center, Moffett Field, CA, USA
| | - Vincent Mysliwiec
- STRONG STAR ORU, Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center, San Antonio, TX, USA
| | - P. Daniel Patterson
- Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kathryn J. Reid
- Center for Circadian and Sleep Medicine, Department of Neurology, Division of Sleep Medicine, Northwestern University, Chicago, IL, USA
| | - Charles Samuels
- Centre for Sleep and Human Performance, Calgary, Alberta, Canada
| | - Nita Lewis Shattuck
- Operations Research Department, Naval Postgraduate School, Monterey, CA, USA
| | - Uzma Kazmi
- American Academy of Sleep Medicine, Darien, IL, USA
| | | | | | - Hans P.A. Van Dongen
- Sleep and Performance Research Center, Washington State University, Spokane, WA, USA
- Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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11
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Gurubhagavatula I, Barger LK, Barnes CM, Basner M, Boivin DB, Dawson D, Drake CL, Flynn-Evans EE, Mysliwiec V, Patterson PD, Reid KJ, Samuels C, Shattuck NL, Kazmi U, Carandang G, Heald JL, Van Dongen HPA. Guiding principles for determining work shift duration and addressing the effects of work shift duration on performance, safety, and health: guidance from the American Academy of Sleep Medicine and the Sleep Research Society. Sleep 2021; 44:6312566. [PMID: 34373924 DOI: 10.1093/sleep/zsab161] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/17/2021] [Indexed: 11/12/2022] Open
Abstract
Risks associated with fatigue that accumulates during work shifts have historically been managed through working time arrangements that specify fixed maximum durations of work shifts and minimum durations of time off. By themselves, such arrangements are not sufficient to curb risks to performance, safety, and health caused by misalignment between work schedules and the biological regulation of waking alertness and sleep. Science-based approaches for determining shift duration and mitigating associated risks, while addressing operational needs, require: (1) a recognition of the factors contributing to fatigue and fatigue-related risks; (2) an understanding of evidence-based countermeasures that may reduce fatigue and/or fatigue-related risks; and (3) an informed approach to selecting workplace-specific strategies for managing work hours. We propose a series of guiding principles to assist stakeholders with designing a shift duration decision-making process that effectively balances the need to meet operational demands with the need to manage fatigue-related risks.
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Affiliation(s)
- Indira Gurubhagavatula
- Division of Sleep Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Laura K Barger
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Christopher M Barnes
- Department of Management and Organization, Foster School of Business, University of Washington, Seattle, WA, USA
| | - Mathias Basner
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Diane B Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Drew Dawson
- Appleton Institute, Central Queensland University, Wayville, SA, Australia
| | | | - Erin E Flynn-Evans
- Fatigue Countermeasures Laboratory, NASA Ames Research Center, Moffett Field, CA, USA
| | - Vincent Mysliwiec
- STRONG STAR ORU, Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center, San Antonio, TX, USA
| | - P Daniel Patterson
- Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kathryn J Reid
- Center for Circadian and Sleep Medicine, Department of Neurology, Division of Sleep Medicine, Northwestern University, Chicago, IL, USA
| | - Charles Samuels
- Centre for Sleep and Human Performance, Calgary, Alberta, Canada
| | - Nita Lewis Shattuck
- Operations Research Department, Naval Postgraduate School, Monterey, CA, USA
| | - Uzma Kazmi
- American Academy of Sleep Medicine, Darien, IL, USA
| | | | | | - Hans P A Van Dongen
- Sleep and Performance Research Center, Washington State University, Spokane, WA, USA.,Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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12
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Zhou Y, Chen Q, Luo X, Li L, Ru T, Zhou G. Does Bright Light Counteract the Post-lunch Dip in Subjective States and Cognitive Performance Among Undergraduate Students? Front Public Health 2021; 9:652849. [PMID: 34164367 PMCID: PMC8215386 DOI: 10.3389/fpubh.2021.652849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 04/19/2021] [Indexed: 11/24/2022] Open
Abstract
The post-lunch dip in alertness and performance was widely experienced during the early afternoon. Taking a short nap was documented as a practical strategy for habitual nappers to counteract the decline of alertness and performance. Yet, it remains unknown whether bright light exposure in the early afternoon working hours could alleviate the performance deficits caused by a post-lunch nap loss for habitual nappers. Seventeen undergraduate students who had a long-term habit of taking a post-lunch nap were assigned to three interventions: (1) a short nap + normal indoor light (100 lx, 4,000 K at eye level); (2) no nap + normal indoor light, and (3) no nap + blue-enriched bright light (1,000 lx, 6,500 K at eye level), in which subjective alertness (Karolinska Sleepiness Scale, KSS), mood (Positive and Negative Affect Schedule, PANAS), and task performance in sustained attention (psychomotor vigilance test, PVT), response inhibition (go/no-go task), and working memory (paced visual serial addition test, PVSAT) were measured. Results showed that a post-lunch nap deprivation significantly increased subjective sleepiness and negative mood and impaired performance in PVT and PVSAT, while exposure to bright blue-enriched white light vs. normal indoor light in the early afternoon significantly relieved such negative effects on mood, sleepiness, and performance in PVSAT; subjective positive mood and performance in PVT and go/no-go task remained unaffected with light intervention. These findings suggested that bright blue-enriched white light exposure could be a potential strategy for those who are suffering from drowsiness and low working memory following a habitual midday nap loss.
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Affiliation(s)
- Ying Zhou
- Lab of Lighting and Physio-Psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Qingwei Chen
- Lab of Lighting and Physio-Psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Xue Luo
- School of Psychology, South China Normal University, Guangzhou, China
| | - Le Li
- Lab of Lighting and Physio-Psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Taotao Ru
- Lab of Lighting and Physio-Psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Guofu Zhou
- Lab of Lighting and Physio-Psychological Health, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
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13
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Stefani O, Freyburger M, Veitz S, Basishvili T, Meyer M, Weibel J, Kobayashi K, Shirakawa Y, Cajochen C. Changing color and intensity of LED lighting across the day impacts on circadian melatonin rhythms and sleep in healthy men. J Pineal Res 2021; 70:e12714. [PMID: 33378563 DOI: 10.1111/jpi.12714] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 01/09/2023]
Abstract
We examined whether dynamically changing light across a scheduled 16-h waking day influences sleepiness, cognitive performance, visual comfort, melatonin secretion, and sleep under controlled laboratory conditions in healthy men. Fourteen participants underwent a 49-h laboratory protocol in a repeated-measures study design. They spent the first 5 hours in the evening under standard lighting, followed by an 8-h nocturnal sleep episode at habitual bedtimes. Thereafter, volunteers either woke up to static light or to a dynamic light that changed spectrum and intensity across the scheduled 16-h waking day. Following an 8-h nocturnal sleep episode, the volunteers spent another 11 hours either under static or dynamic light. Static light attenuated the evening rise in melatonin levels more compared to dynamic light as indexed by a significant reduction in the melatonin AUC prior to bedtime during static light only. Participants felt less vigilant in the evening during dynamic light. After dynamic light, sleep latency was significantly shorter in both the baseline and treatment night while sleep structure, sleep quality, cognitive performance, and visual comfort did not significantly differ. The study shows that dynamic changes in spectrum and intensity of light promote melatonin secretion and sleep initiation in healthy men.
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Affiliation(s)
- Oliver Stefani
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | - Marlène Freyburger
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
| | - Simon Veitz
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
| | - Tamara Basishvili
- School of Natural Sciences and Medicine, Tengiz Oniani Laboratory of Sleep-Wakefulness Cycle Study, Ilia State University, Tbilisi, Georgia
| | - Martin Meyer
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | - Janine Weibel
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | - Kumpei Kobayashi
- Development and Engineering Department, Toshiba Materials Co. Ltd, Yokohama-City, Japan
| | - Yasuhiro Shirakawa
- Development and Engineering Department, Toshiba Materials Co. Ltd, Yokohama-City, Japan
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
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14
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Kompier ME, Smolders KCHJ, de Kort YAW. Abrupt light transitions in illuminance and correlated colour temperature result in different temporal dynamics and interindividual variability for sensation, comfort and alertness. PLoS One 2021; 16:e0243259. [PMID: 33750954 PMCID: PMC7984641 DOI: 10.1371/journal.pone.0243259] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 03/08/2021] [Indexed: 11/19/2022] Open
Abstract
Detailed insights in both visual effects of light and effects beyond vision due to manipulations in illuminance and correlated color temperature (CCT) are needed to optimize study protocols as well as to design light scenarios for practical applications. This study investigated temporal dynamics and interindividual variability in subjective evaluations of sensation, comfort and mood as well as subjective and objective measures of alertness, arousal and thermoregulation following abrupt transitions in illuminance and CCT in a mild cold environment. The results revealed that effects could be uniquely attributed to changes in illuminance or CCT. No interaction effects of illuminance and CCT were found for any of these markers. Responses to the abrupt transitions in illuminance and CCT always occurred immediately and exclusively amongst the subjective measures. Most of these responses diminished over time within the 45-minute light manipulation. In this period, no responses were found for objective measures of vigilance, arousal or thermoregulation. Significant interindividual variability occurred only in the visual comfort evaluation in response to changes in the intensity of the light. The results indicate that the design of dynamic light scenarios aimed to enhance human alertness and vitality requires tailoring to the individual to create visually comfortable environments.
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Affiliation(s)
- Maaike E. Kompier
- Human-Technology Interaction, School of Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Karin C. H. J. Smolders
- Human-Technology Interaction, School of Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Yvonne A. W. de Kort
- Human-Technology Interaction, School of Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands
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15
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Effect of Indoors Artificial Lighting Conditions on Computer-Based Learning Performance. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17072537. [PMID: 32276306 PMCID: PMC7177684 DOI: 10.3390/ijerph17072537] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/16/2020] [Accepted: 03/23/2020] [Indexed: 11/17/2022]
Abstract
Lighting condition is essential to human performance. With the widespread use of computer-based learning, the performance measurements become difficult, and the effects of artificial lighting conditions towards the new learning forms are not investigated extensively. The current study conducts a subject-within experiment with a 45-min-long online learning along with electroencephalogram (EEG)-based measurements, and a post-interview under five lighting setups respectively (300 lx, 3000 K; 300 lx, 4000 K; 300 lx, 6500 K; 500 lx, 4000 K; 1000 lx, 4000 K). Attention is chosen as the key factor to represent the learning performance. The results show that the attention of people aged in the 20s is not affected by the experimental lighting conditions. The results also demonstrate that people in high illumination at 1000 lx are more inclined to sustain attention despite the discomfort and dissatisfaction. Taking the EEG-based attention measurements and post-interview answers into consideration, lighting conditions at 300 lx, 4000 K are the recommended set points for university architectures among the investigated conditions, providing a practical basis when adjusting the lighting standard for its advantage in energy saving.
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16
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Münch M, Wirz-Justice A, Brown SA, Kantermann T, Martiny K, Stefani O, Vetter C, Wright KP, Wulff K, Skene DJ. The Role of Daylight for Humans: Gaps in Current Knowledge. Clocks Sleep 2020; 2:61-85. [PMID: 33089192 PMCID: PMC7445840 DOI: 10.3390/clockssleep2010008] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/21/2020] [Indexed: 01/04/2023] Open
Abstract
Daylight stems solely from direct, scattered and reflected sunlight, and undergoes dynamic changes in irradiance and spectral power composition due to latitude, time of day, time of year and the nature of the physical environment (reflections, buildings and vegetation). Humans and their ancestors evolved under these natural day/night cycles over millions of years. Electric light, a relatively recent invention, interacts and competes with the natural light-dark cycle to impact human biology. What are the consequences of living in industrialised urban areas with much less daylight and more use of electric light, throughout the day (and at night), on general health and quality of life? In this workshop report, we have classified key gaps of knowledge in daylight research into three main groups: (I) uncertainty as to daylight quantity and quality needed for "optimal" physiological and psychological functioning, (II) lack of consensus on practical measurement and assessment methods and tools for monitoring real (day) light exposure across multiple time scales, and (III) insufficient integration and exchange of daylight knowledge bases from different disciplines. Crucial short and long-term objectives to fill these gaps are proposed.
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Affiliation(s)
- Mirjam Münch
- Sleep/Wake Research Centre, Massey University Wellington, Wellington 6021, New Zealand
| | - Anna Wirz-Justice
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4002 Basel, Switzerland; (A.W.-J.); (O.S.)
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, 4002 Basel, Switzerland
| | - Steven A. Brown
- Chronobiology and Sleep Research Group, Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland;
| | - Thomas Kantermann
- Faculty for Health and Social Affairs, University of Applied Sciences for Economics and Management (FOM), 45141 Essen, Germany;
- SynOpus, 44789 Bochum, Germany
| | - Klaus Martiny
- Psychiatric Center Copenhagen, University of Copenhagen, Rigshospitalet, 2100 Copenhagen, Denmark;
| | - Oliver Stefani
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4002 Basel, Switzerland; (A.W.-J.); (O.S.)
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, 4002 Basel, Switzerland
| | - Céline Vetter
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; (C.V.); (K.P.W.J.)
| | - Kenneth P. Wright
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; (C.V.); (K.P.W.J.)
- Division of Endocrinology, Metabolism and Diabetes, University of Colorado, Aurora, CO 80045, USA
| | - Katharina Wulff
- Departments of Radiation Sciences and Molecular Biology, Umeå University, 901 87 Umeå, Sweden;
- Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, 901 87 Umeå, Sweden
| | - Debra J. Skene
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK;
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17
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Lok R, van Koningsveld MJ, Gordijn MCM, Beersma DGM, Hut RA. Daytime melatonin and light independently affect human alertness and body temperature. J Pineal Res 2019; 67:e12583. [PMID: 31033013 PMCID: PMC6767594 DOI: 10.1111/jpi.12583] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/17/2019] [Accepted: 04/19/2019] [Indexed: 12/01/2022]
Abstract
Light significantly improves alertness during the night (Cajochen, Sleep Med Rev, 11, 2007 and 453; Ruger et al., AJP Regul Integr Comp Physiol, 290, 2005 and R1413), but results are less conclusive at daytime (Lok et al., J Biol Rhythms, 33, 2018 and 589). Melatonin and core body temperature levels at those times of day may contribute to differences in alerting effects of light. In this experiment, the combined effect of daytime exogenous melatonin administration and light intensity on alertness, body temperature, and skin temperature was studied. The goal was to assess whether (a) alerting effects of light are melatonin dependent, (b) soporific effects of melatonin are mediated via the thermoregulatory system, and (c) light can improve alertness after melatonin-induced sleepiness during daytime. 10 subjects (5 females, 5 males) received melatonin (5 mg) in dim (10 lux) and, on a separate occasion, in bright polychromatic white light (2000 lux). In addition, they received placebo both under dim and bright light conditions. Subjects participated in all four conditions in a balanced order, yielding a balanced within-subject design, lasting from noon to 04:00 pm. Alertness and performance were assessed half hourly, while body temperature and skin temperature were measured continuously. Saliva samples to detect melatonin concentrations were collected half hourly. Melatonin administration increased melatonin concentrations in all subjects. Subjective sleepiness and distal skin temperature increased after melatonin ingestion. Bright light exposure after melatonin administration did not change subjective alertness scores, but body temperature and proximal skin temperature increased, while distal skin temperature decreased. Light exposure did not significantly affect these parameters in the placebo condition. These results indicate that (a) exogenous melatonin administration during daytime increases subjective sleepiness, confirming a role for melatonin in sleepiness regulation, (b) bright light exposure after melatonin ingestion significantly affected thermoregulatory parameters without altering subjective sleepiness, therefore temperature changes seem nonessential for melatonin-induced sleepiness, (c) subjective sleepiness was increased by melatonin ingestion, but bright light administration was not able to improve melatonin-induced sleepiness feelings nor performance. Other (physiological) factors may therefore contribute to differences in alerting effects of light during daytime and nighttime.
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Affiliation(s)
- Renske Lok
- Chronobiology Unit, Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Minke J. van Koningsveld
- Chronobiology Unit, Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Marijke C. M. Gordijn
- Chronobiology Unit, Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Chrono@WorkGroningenThe Netherlands
| | - Domien G. M. Beersma
- Chronobiology Unit, Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Roelof A. Hut
- Chronobiology Unit, Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
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18
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de Zeeuw J, Papakonstantinou A, Nowozin C, Stotz S, Zaleska M, Hädel S, Bes F, Münch M, Kunz D. Living in Biological Darkness: Objective Sleepiness and the Pupillary Light Responses Are Affected by Different Metameric Lighting Conditions during Daytime. J Biol Rhythms 2019; 34:410-431. [PMID: 31156018 PMCID: PMC6637815 DOI: 10.1177/0748730419847845] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nighttime melatonin suppression is the most commonly used method to indirectly quantify acute nonvisual light effects. Since light is the principal zeitgeber in humans, there is a need to assess its strength during daytime as well. This is especially important since humans evolved under natural daylight but now often spend their time indoors under artificial light, resulting in a different quality and quantity of light. We tested whether the pupillary light response (PLR) could be used as a marker for nonvisual light effects during daytime. We also recorded the wake electroencephalogram to objectively determine changes in daytime sleepiness between different illuminance levels and/or spectral compositions of light. In total, 72 participants visited the laboratory 4 times for 3-h light exposures. All participants underwent a dim-light condition and either 3 metameric daytime light exposures with different spectral compositions of polychromatic white light (100 photopic lux, peak wavelengths at 435 nm or 480 nm, enriched with longer wavelengths of light) or 3 different illuminances (200, 600, and 1200 photopic lux) with 1 metameric lighting condition (peak wavelength at 435 nm or 480 nm; 24 participants each). The results show that the PLR was sensitive to both spectral differences between metameric lighting conditions and different illuminances in a dose-responsive manner, depending on melanopic irradiance. Objective sleepiness was significantly reduced, depending on melanopic irradiance, at low illuminance (100 lux) and showed fewer differences at higher illuminance. Since many people are exposed to such low illuminance for most of their day—living in biological darkness—our results imply that optimizing the light spectrum could be important to improve daytime alertness. Our results suggest the PLR as a noninvasive physiological marker for ambient light exposure effects during daytime. These findings may be applied to assess light-dependent zeitgeber strength and evaluate lighting improvements at workplaces, schools, hospitals, and homes.
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Affiliation(s)
- Jan de Zeeuw
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Sleep Research & Clinical Chronobiology.,Intellux GmbH, Berlin, Germany
| | - Alexandra Papakonstantinou
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Sleep Research & Clinical Chronobiology.,St. Hedwig-Hospital, Clinic for Sleep & Chronomedicine, Berlin
| | - Claudia Nowozin
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Sleep Research & Clinical Chronobiology.,St. Hedwig-Hospital, Clinic for Sleep & Chronomedicine, Berlin
| | - Sophia Stotz
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Sleep Research & Clinical Chronobiology.,St. Hedwig-Hospital, Clinic for Sleep & Chronomedicine, Berlin
| | | | - Sven Hädel
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Sleep Research & Clinical Chronobiology
| | - Frederik Bes
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Sleep Research & Clinical Chronobiology.,St. Hedwig-Hospital, Clinic for Sleep & Chronomedicine, Berlin
| | - Mirjam Münch
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Sleep Research & Clinical Chronobiology.,St. Hedwig-Hospital, Clinic for Sleep & Chronomedicine, Berlin.,Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Medical Immunology, Laboratory of Chronobiology.,Sleep/Wake Research Centre, Massey University, Wellington, New Zealand
| | - Dieter Kunz
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Physiology, Sleep Research & Clinical Chronobiology.,Intellux GmbH, Berlin, Germany.,St. Hedwig-Hospital, Clinic for Sleep & Chronomedicine, Berlin
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19
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Lok R, Smolders KCHJ, Beersma DGM, de Kort YAW. Light, Alertness, and Alerting Effects of White Light: A Literature Overview. J Biol Rhythms 2018; 33:589-601. [PMID: 30191746 PMCID: PMC6236641 DOI: 10.1177/0748730418796443] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Light is known to elicit non-image-forming responses, such as effects on alertness. This has been reported especially during light exposure at night. Nighttime results might not be translatable to the day. This article aims to provide an overview of (1) neural mechanisms regulating alertness, (2) ways of measuring and quantifying alertness, and (3) the current literature specifically regarding effects of different intensities of white light on various measures and correlates of alertness during the daytime. In general, the present literature provides inconclusive results on alerting effects of the intensity of white light during daytime, particularly for objective measures and correlates of alertness. However, the various research paradigms employed in earlier studies differed substantially, and most studies tested only a limited set of lighting conditions. Therefore, the alerting potential of exposure to more intense white light should be investigated in a systematic, dose-dependent manner with multiple correlates of alertness and within one experimental paradigm over the course of day.
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Affiliation(s)
- Renske Lok
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | - Karin C H J Smolders
- Human-Technology Interaction, School of Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Domien G M Beersma
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | - Yvonne A W de Kort
- Human-Technology Interaction, School of Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands
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20
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Lok R, Woelders T, Gordijn MCM, Hut RA, Beersma DGM. White Light During Daytime Does Not Improve Alertness in Well-rested Individuals. J Biol Rhythms 2018; 33:637-648. [PMID: 30191761 PMCID: PMC6236585 DOI: 10.1177/0748730418796036] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Broad-spectrum light applied during the night has been shown to affect alertness in a
dose-dependent manner. The goal of this experiment was to investigate whether a similar
relationship could be established for light exposure during daytime. Fifty healthy
participants were subjected to a paradigm (0730-1730 h) in which they were intermittently
exposed to 1.5 h of dim light (<10 lux) and 1 h of experimental light (24-2000 lux).
The same intensity of experimental light was used throughout the day, resulting in groups
of 10 subjects per intensity. Alertness was assessed with subjective and multiple
objective measures. A significant effect of time of day was found in all parameters of
alertness (p < 0.05). Significant dose-response relationships between
light intensity and alertness during the day could be determined in a few of the
parameters of alertness at some times of the day; however, none survived correction for
multiple testing. We conclude that artificial light applied during daytime at intensities
up to 2000 lux does not elicit significant improvements in alertness in non-sleep-deprived
subjects.
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Affiliation(s)
- Renske Lok
- University of Groningen, Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, Groningen, the Netherlands
| | - Tom Woelders
- University of Groningen, Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, Groningen, the Netherlands
| | - Marijke C M Gordijn
- University of Groningen, Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, Groningen, the Netherlands.,Chrono@Work, Groningen, the Netherlands
| | - Roelof A Hut
- University of Groningen, Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, Groningen, the Netherlands
| | - Domien G M Beersma
- University of Groningen, Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, Groningen, the Netherlands
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