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Bauducco S, Pillion M, Bartel K, Reynolds C, Kahn M, Gradisar M. A bidirectional model of sleep and technology use: A theoretical review of How much, for whom, and which mechanisms. Sleep Med Rev 2024; 76:101933. [PMID: 38657359 DOI: 10.1016/j.smrv.2024.101933] [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: 09/30/2023] [Revised: 03/01/2024] [Accepted: 04/05/2024] [Indexed: 04/26/2024]
Abstract
The link between technology and sleep is more complex than originally thought. In this updated theoretical review, we propose a new model informed by the growing body of evidence in the area over the past 10 years. The main theoretical change is the addition of bi-directional links between the use of technology and sleep problems. We begin by reviewing the evidence to date for the originally proposed mechanisms of bright light, arousal, nighttime sleep disruptions, and sleep displacement. Then, in support of the new direction of effect (sleep problems preceding technology use), we propose two new mechanisms: technology before sleep might be used as a time filler and/or as an emotional regulation strategy to facilitate the sleep-onset process. Finally, we present potential moderators of the association between technology and sleep, in recognition of protective and vulnerability factors that may mitigate or exacerbate the effects of technology on sleep and vice versa. The goal of this theoretical review is to update the field, guide future public health messages, and to prompt new research into how much technology and sleep affect each other, for whom it may be problematic, and which mechanisms may explain their association.
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Affiliation(s)
- Serena Bauducco
- Örebro University, School of Behavioural, Social and Legal Sciences, Sweden; Flinders University, College of Education, Psychology and Social Work, Australia.
| | - Meg Pillion
- Flinders University, College of Education, Psychology and Social Work, Australia
| | - Kate Bartel
- WINK Sleep Pty Ltd, Adelaide, Australia; Riverland Academy of Clinical Excellence, Riverland Mallee Coorong Local Health Network, Australia; Flinders University, College of Medicine and Public Health, Australia
| | - Chelsea Reynolds
- Flinders University, College of Education, Psychology and Social Work, Australia; WINK Sleep Pty Ltd, Adelaide, Australia
| | - Michal Kahn
- Tel Aviv University, School of Psychological Sciences, Israel
| | - Michael Gradisar
- WINK Sleep Pty Ltd, Adelaide, Australia; Sleep Cycle AB, Gothenburg, Sweden
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Cajochen C, Reichert CF, Münch M, Gabel V, Stefani O, Chellappa SL, Schmidt C. Ultradian sleep cycles: Frequency, duration, and associations with individual and environmental factors-A retrospective study. Sleep Health 2024; 10:S52-S62. [PMID: 37914631 DOI: 10.1016/j.sleh.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 09/04/2023] [Accepted: 09/06/2023] [Indexed: 11/03/2023]
Abstract
OBJECTIVE Sleep varies between individuals in response to sleep-wake history and various environmental factors, including light and noise. Here we report on the intranight variation of the ultradian nonrapid eye movement-rapid eye movement (NREM-REM) sleep cycle in 369 participants who have contributed to different laboratory studies from 1994 to 2020 at the Centre for Chronobiology, Basel, Switzerland. RESULTS We observed a large interindividual variability in sleep cycle duration, including NREM and REM sleep episodes in healthy participants who were given an 8-hour sleep opportunity at habitual bedtime in controlled laboratory settings. The median sleep cycle duration was 96 minutes out of 6064 polysomnographically-recorded cycles. The number and duration of cycles were not normally distributed, and the distribution became narrower for NREM sleep and wider for REM sleep later in the night. The first cycle was consistently shorter than subsequent cycles, and moderate presleep light or nocturnal noise exposure had no significant effects on ultradian sleep cycle duration. Age and sex significantly affected NREM and REM sleep duration, with older individuals having longer NREM and shorter REM sleep particularly in the end of the night, and females having longer NREM sleep episodes. High sleep pressure (ie, sleep deprivation) and low sleep pressure (ie, multiple naps) altered ultradian sleep cycles, with high sleep pressure leading to longer NREM sleep in the first cycle, and low sleep pressure leading to longer REM sleep episodes. Positive correlations were observed between N2 and NREM duration, and between N1 and REM duration. Weak intrasleep REM sleep homeostasis was also evident in our data set. CONCLUSIONS We conclude that ultradian sleep cycles are endogenous biological rhythms modulated by age, sex, and sleep homeostasis, but not directly responsive to (moderate levels of) environmental cues in healthy good sleepers.
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Affiliation(s)
- Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland; Research Cluster Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland.
| | - Carolin Franziska Reichert
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland; Research Cluster Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | - Mirjam Münch
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland; Research Cluster Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | | | - Oliver Stefani
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland; Research Cluster Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | - Sarah Laxhmi Chellappa
- School of Psychology, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Christina Schmidt
- Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium; Psychology and Neuroscience of Cognition Research Unit (PsyNCog), Faculty of Psychology, Speech and Language, University of Liège, Liège, Belgium
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3
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Wang Y, Deboer T. Hypnotic effects of melatonin depend on the environmental lighting conditions in the rat. J Pineal Res 2024; 76:e12928. [PMID: 38031385 DOI: 10.1111/jpi.12928] [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: 08/21/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/01/2023]
Abstract
Acute effects of exogenous melatonin have been widely reported to promote sleep or induce drowsiness in human. However, testing of the hypnotic effects of melatonin in nocturnal rodents has yielded contradictory results. The latter may be associated with differences in concentration, lighting conditions, time of administration of melatonin, and possibly the type of analysis. In this study, electroencephalogram (EEG) and electromyogram were recorded in pigmented male Brown Norway rats under both light-dark (LD) and constant dark (DD) conditions. Melatonin was administered intraperitoneally at a moderate dose of 3 mg/kg, at either 1 h after lights on under LD condition or 1 h after the activity offset under DD condition. The dosage is known to be able to entrain nocturnal rodents in DD conditions, but does not change sleep in rodents in LD. Only the rats under DD conditions showed a significant reduction in nonrapid eye movement (NREM) sleep latency, while the NREM sleep power spectrum remained unaffected. Under LD condition, melatonin did not alter NREM and rapid eye movement (REM) sleep latency, and had only minor effects on the NREM sleep EEG. Regardless of lighting conditions, melatonin administration resulted in less, but longer episodes for all vigilance states suggesting increased vigilance state consolidation. In the discussion, we compare our results with a summary of previously published data concerning the hypnotic effects of melatonin in polysomnographic/EEG-confirmed sleep in humans and nocturnal rodents. In conclusion, the hypnotic effect of exogenous melatonin in nocturnal rodents not only depends on the time of day, and concentration, but is also influenced by the lighting conditions. Regardless of inducing sleep or not, melatonin may consolidate sleep and through that enhance sleep quality.
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Affiliation(s)
- Yumeng Wang
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Tom Deboer
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
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Schöllhorn I, Stefani O, Blume C, Cajochen C. Seasonal Variation in the Responsiveness of the Melanopsin System to Evening Light: Why We Should Report Season When Collecting Data in Human Sleep and Circadian Studies. Clocks Sleep 2023; 5:651-666. [PMID: 37987395 PMCID: PMC10660855 DOI: 10.3390/clockssleep5040044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/07/2023] [Accepted: 10/09/2023] [Indexed: 11/22/2023] Open
Abstract
It is well known that variations in light exposure during the day affect light sensitivity in the evening. More daylight reduces sensitivity, and less daylight increases it. On average days, we spend less time outdoors in winter and receive far less light than in summer. Therefore, it could be relevant when collecting research data on the non-image forming (NIF) effects of light on circadian rhythms and sleep. In fact, studies conducted only in winter may result in more pronounced NIF effects than in summer. Here, we systematically collected information on the extent to which studies on the NIF effects of evening light include information on season and/or light history. We found that more studies were conducted in winter than in summer and that reporting when a study was conducted or measuring individual light history is not currently a standard in sleep and circadian research. In addition, we sought to evaluate seasonal variations in a previously published dataset of 72 participants investigating circadian and sleep effects of evening light exposure in a laboratory protocol where daytime light history was not controlled. In this study, we selectively modulated melanopic irradiance at four different light levels (<90 lx). Here, we aimed to retrospectively evaluate seasonal variations in the responsiveness of the melanopsin system by combining all data sets in an exploratory manner. Our analyses suggest that light sensitivity is indeed reduced in summer compared to winter. Thus, to increase the reproducibility of NIF effects on sleep and circadian measures, we recommend an assessment of the light history and encourage standardization of reporting guidelines on the seasonal distribution of measurements.
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Affiliation(s)
- Isabel Schöllhorn
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4002 Basel, Switzerland; (I.S.); (O.S.)
- Research Cluster Molecular and Cognitive Neurosciences (MCN), University of Basel, 4001 Basel, Switzerland
| | - Oliver Stefani
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4002 Basel, Switzerland; (I.S.); (O.S.)
- Research Cluster Molecular and Cognitive Neurosciences (MCN), University of Basel, 4001 Basel, Switzerland
- Lucerne University of Applied Sciences and Arts, Engineering and Architecture, Technikumstrasse 21, 6048 Horw, Switzerland
| | - Christine Blume
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4002 Basel, Switzerland; (I.S.); (O.S.)
- Research Cluster Molecular and Cognitive Neurosciences (MCN), University of Basel, 4001 Basel, Switzerland
- Department of Biomedicine, University of Basel, 4001 Basel, Switzerland
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, 4002 Basel, Switzerland; (I.S.); (O.S.)
- Research Cluster Molecular and Cognitive Neurosciences (MCN), University of Basel, 4001 Basel, Switzerland
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Hilditch CJ, Bansal K, Chachad R, Wong LR, Bathurst NG, Feick NH, Santamaria A, Shattuck NL, Garcia JO, Flynn-Evans EE. Reconfigurations in brain networks upon awakening from slow wave sleep: Interventions and implications in neural communication. Netw Neurosci 2023; 7:102-121. [PMID: 37334002 PMCID: PMC10270716 DOI: 10.1162/netn_a_00272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/05/2022] [Indexed: 04/04/2024] Open
Abstract
Sleep inertia is the brief period of impaired alertness and performance experienced immediately after waking. Little is known about the neural mechanisms underlying this phenomenon. A better understanding of the neural processes during sleep inertia may offer insight into the awakening process. We observed brain activity every 15 min for 1 hr following abrupt awakening from slow wave sleep during the biological night. Using 32-channel electroencephalography, a network science approach, and a within-subject design, we evaluated power, clustering coefficient, and path length across frequency bands under both a control and a polychromatic short-wavelength-enriched light intervention condition. We found that under control conditions, the awakening brain is typified by an immediate reduction in global theta, alpha, and beta power. Simultaneously, we observed a decrease in the clustering coefficient and an increase in path length within the delta band. Exposure to light immediately after awakening ameliorated changes in clustering. Our results suggest that long-range network communication within the brain is crucial to the awakening process and that the brain may prioritize these long-range connections during this transitional state. Our study highlights a novel neurophysiological signature of the awakening brain and provides a potential mechanism by which light improves performance after waking.
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Affiliation(s)
- Cassie J. Hilditch
- Fatigue Countermeasures Laboratory, Department of Psychology, San José State University, San José, CA, USA
| | - Kanika Bansal
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
- US DEVCOM Army Research Laboratory, Humans in Complex Systems Division, Aberdeen Proving Ground, MD, USA
| | - Ravi Chachad
- Fatigue Countermeasures Laboratory, Department of Psychology, San José State University, San José, CA, USA
| | - Lily R. Wong
- Fatigue Countermeasures Laboratory, Department of Psychology, San José State University, San José, CA, USA
| | - Nicholas G. Bathurst
- Fatigue Countermeasures Laboratory, Human Systems Integration Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Nathan H. Feick
- Fatigue Countermeasures Laboratory, Department of Psychology, San José State University, San José, CA, USA
| | - Amanda Santamaria
- Cognitive and Systems Neuroscience Research Hub, University of South Australia, Adelaide, SA, Australia
| | - Nita L. Shattuck
- Operations Research Department, Naval Postgraduate School, Monterey, CA, USA
| | - Javier O. Garcia
- US DEVCOM Army Research Laboratory, Humans in Complex Systems Division, Aberdeen Proving Ground, MD, USA
| | - Erin E. Flynn-Evans
- Fatigue Countermeasures Laboratory, Human Systems Integration Division, NASA Ames Research Center, Moffett Field, CA, USA
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Season is related to the slow wave and sigma activity of infants and toddlers. Sleep Med 2022; 100:364-377. [PMID: 36201888 DOI: 10.1016/j.sleep.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/05/2022] [Accepted: 09/08/2022] [Indexed: 01/12/2023]
Abstract
OBJECTIVE/BACKGROUND Slow wave activity (SWA) and sigma frequency activity (SFA) are hallmarks of NREM sleep EEG and important indicators of neural plasticity, development of the central nervous system, and cognition. However, little is known about the factors that modulate these sleep EEG activities, especially in small children. PATIENTS/METHODS We analyzed the power spectral densities of SWA (1-4 Hz) and SFA range (10-15 Hz) from six EEG derivations of 56 infants (8 months) and 60 toddlers (24 months) during their all-night sleep and during the first and the last half of night sleep. The spectral values were compared between the four seasons. RESULTS In the spring group of infants, compared with the darker seasons, SFA was lower in the centro-occipital EEG derivations during both halves of the night. The SWA findings of the infants were restricted to the last half of the night (SWA2) and frontally, where SWA2 was higher during winter than spring. The toddlers presented less frontal SWA2 during winter compared with autumn. Both age groups showed a reduction in both SWA and SFA towards the last half of the night. CONCLUSIONS The sleep EEG spectral power densities are more often associated with seasons in infants' SFA range. The results might stem from seasonally changing light exposure, but the exact mechanism warrants further study. Moreover, contrary to the adult-like increment of SFA, the SFA at both ages was lower at the last part of the night sleep. This suggests different regulation of spindle activity in infants and toddlers.
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Blume C, Niedernhuber M, Spitschan M, Slawik HC, Meyer MP, Bekinschtein TA, Cajochen C. Melatonin suppression does not automatically alter sleepiness, vigilance, sensory processing, or sleep. Sleep 2022; 45:zsac199. [PMID: 35998110 PMCID: PMC9644120 DOI: 10.1093/sleep/zsac199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/02/2022] [Indexed: 09/19/2023] Open
Abstract
Presleep exposure to short-wavelength light suppresses melatonin and decreases sleepiness with activating effects extending to sleep. This has mainly been attributed to melanopic effects, but mechanistic insights are missing. Thus, we investigated whether two light conditions only differing in the melanopic effects (123 vs. 59 lx melanopic EDI) differentially affect sleep besides melatonin. Additionally, we studied whether the light differentially modulates sensory processing during wakefulness and sleep. Twenty-nine healthy volunteers (18-30 years, 15 women) were exposed to two metameric light conditions (high- vs. low-melanopic, ≈60 photopic lx) for 1 h ending 50 min prior to habitual bed time. This was followed by an 8-h sleep opportunity with polysomnography. Objective sleep measurements were complemented by self-report. Salivary melatonin, subjective sleepiness, and behavioral vigilance were sampled at regular intervals. Sensory processing was evaluated during light exposure and sleep on the basis of neural responses related to violations of expectations in an oddball paradigm. We observed suppression of melatonin by ≈14% in the high- compared to the low-melanopic condition. However, conditions did not differentially affect sleep, sleep quality, sleepiness, or vigilance. A neural mismatch response was evident during all sleep stages, but not differentially modulated by light. Suppression of melatonin by light targeting the melanopic system does not automatically translate to acutely altered levels of vigilance or sleepiness or to changes in sleep, sleep quality, or basic sensory processing. Given contradicting earlier findings and the retinal anatomy, this may suggest that an interaction between melanopsin and cone-rod signals needs to be considered. Clinical Trial Registry: German Clinical Trials Register, DRKS00023602, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00023602.
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Affiliation(s)
- Christine Blume
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland (institution, where the work was performed)
- Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
| | - Maria Niedernhuber
- Consciousness and Cognition Lab, Department of Psychology, University of Cambridge, Cambridge, UK
| | - Manuel Spitschan
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland (institution, where the work was performed)
- Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
- Translational Sensory and Circadian Neuroscience, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- TUM Department of Sport and Health Sciences (TUM SG), Technical University of Munich, Munich, Germany
| | - Helen C Slawik
- Psychiatric Hospital of the University of Basel, Basel, Switzerland
| | - Martin P Meyer
- Psychiatric Hospital of the University of Basel, Basel, Switzerland
| | - Tristan A Bekinschtein
- Consciousness and Cognition Lab, Department of Psychology, University of Cambridge, Cambridge, UK
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland (institution, where the work was performed)
- Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland
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Pun TB, Phillips CL, Marshall NS, Comas M, Hoyos CM, D’Rozario AL, Bartlett DJ, Davis W, Hu W, Naismith SL, Cain S, Postnova S, Grunstein RR, Gordon CJ. The Effect of Light Therapy on Electroencephalographic Sleep in Sleep and Circadian Rhythm Disorders: A Scoping Review. Clocks Sleep 2022; 4:358-373. [PMID: 35997384 PMCID: PMC9397048 DOI: 10.3390/clockssleep4030030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 07/21/2022] [Accepted: 08/02/2022] [Indexed: 01/27/2023] Open
Abstract
Light therapy is used to treat sleep and circadian rhythm disorders, yet there are limited studies on whether light therapy impacts electroencephalographic (EEG) activity during sleep. Therefore, we aimed to provide an overview of research studies that examined the effects of light therapy on sleep macro- and micro-architecture in populations with sleep and circadian rhythm disorders. We searched for randomized controlled trials that used light therapy and included EEG sleep measures using MEDLINE, PubMed, CINAHL, PsycINFO and Cochrane Central Register of Controlled Trials databases. Five articles met the inclusion criteria of patients with either insomnia or delayed sleep−wake phase disorder (DSWPD). These trials reported sleep macro-architecture outcomes using EEG or polysomnography. Three insomnia trials showed no effect of the timing or intensity of light therapy on total sleep time, wake after sleep onset, sleep efficiency and sleep stage duration compared to controls. Only one insomnia trial reported significantly higher sleep efficiency after evening light therapy (>4000 lx between 21:00−23:00 h) compared with afternoon light therapy (>4000 lx between 15:00−17:00 h). In the only DSWPD trial, six multiple sleep latency tests were conducted across the day (09:00 and 19:00 h) and bright light (2500 lx) significantly lengthened sleep latency in the morning (09:00 and 11:00 h) compared to control light (300 lx). None of the five trials reported any sleep micro-architecture measures. Overall, there was limited research about the effect of light therapy on EEG sleep measures, and studies were confined to patients with insomnia and DSWPD only. More research is needed to better understand whether lighting interventions in clinical populations affect sleep macro- and micro-architecture and objective sleep timing and quality.
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Affiliation(s)
- Teha B. Pun
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
| | - Craig L. Phillips
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Nathaniel S. Marshall
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
| | - Maria Comas
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
| | - Camilla M. Hoyos
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Angela L. D’Rozario
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Delwyn J. Bartlett
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
| | - Wendy Davis
- School of Architecture, Design and Planning, The University of Sydney, Sydney, NSW 2008, Australia
| | - Wenye Hu
- School of Architecture, Design and Planning, The University of Sydney, Sydney, NSW 2008, Australia
| | - Sharon L. Naismith
- Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW 2050, Australia
| | - Sean Cain
- School of Psychological Sciences and Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC 3800, Australia
| | - Svetlana Postnova
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- School of Physics, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ron R. Grunstein
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Sleep and Severe Mental Illness Clinic, CPC-RPA Clinic, Royal Prince Alfred Hospital, Sydney, NSW 2050, Australia
| | - Christopher J. Gordon
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2050, Australia
- CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, Sydney, NSW 2037, Australia
- Correspondence: ; Tel.: +61-2-9351-0586
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Lok R, Woelders T, van Koningsveld MJ, Oberman K, Fuhler SG, Beersma DGM, Hut RA. Bright Light Decreases Peripheral Skin Temperature in Healthy Men: A Forced Desynchrony Study Under Dim and Bright Light (II). J Biol Rhythms 2022; 37:417-428. [PMID: 35723003 PMCID: PMC9326805 DOI: 10.1177/07487304221096948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Human thermoregulation is strictly regulated by the preoptic area of the hypothalamus, which is directly influenced by the suprachiasmatic nucleus (SCN). The main input pathway of the SCN is light. Here, thermoregulatory effects of light were assessed in humans in a forced desynchrony (FD) design. The FD experiment was performed in dim light (DL, 6 lux) and bright white light (BL, 1300 lux) in 8 men in a semi-randomized within-subject design. A 4 × 18 h FD protocol (5 h sleep, 13 h wake) was applied, with continuous core body temperature (CBT) and skin temperature measurements at the forehead, clavicles, navel, palms, foot soles and toes. Skin temperature parameters indicated sleep-wake modulations as well as internal clock variations. All distal skin temperature parameters increased during sleep, when CBT decreased. Light significantly affected temperature levels during the wake phase, with decreased temperature measured at the forehead and toes and increased navel and clavicular skin temperatures. These effects persisted when the lights were turned off for sleep. Circadian amplitude of CBT and all skin temperature parameters decreased significantly during BL exposure. Circadian proximal skin temperatures cycled in phase with CBT, while distal skin temperatures cycled in anti-phase, confirming the idea that distal skin regions reflect heat dissipation and proximal regions approximate CBT. In general, we find that increased light intensity exposure may have decreased heat loss in humans, especially at times when the circadian system promotes sleep.
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Affiliation(s)
- R Lok
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherland.,Department of Psychiatry and Behavioral Sciences, Stanford University, Palo Alto, California, USA.,University of Groningen, Leeuwarden, the Netherlands
| | - T Woelders
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherland
| | - M J van Koningsveld
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherland
| | - K Oberman
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherland
| | - S G Fuhler
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherland
| | - D G M Beersma
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherland
| | - R A Hut
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherland
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10
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Evening light environments can be designed to consolidate and increase the duration of REM-sleep. Sci Rep 2022; 12:8719. [PMID: 35610265 PMCID: PMC9130237 DOI: 10.1038/s41598-022-12408-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 05/04/2022] [Indexed: 01/15/2023] Open
Abstract
Evening exposure to short-wavelength light has disruptive effects on circadian rhythms and sleep. These effects can be mitigated by blocking short-wavelength (blue) frequencies, which has led to the development of evening blue-depleted light environments (BDLEs). We have previously reported that residing 5 days in an evening BDLE, compared with residing in a normal indoor light environment of similar photopic lux, advances circadian rhythms and increases the duration of rapid eye movement (REM) sleep in a randomized cross-over trial with twelve healthy participants. The current study extends these findings by testing whether residing in the evening BDLE affects the consolidation and microstructure of REM sleep in the same sample. Evening BDLE significantly reduces the fragmentation of REM sleep (p = 0.0003), and REM sleep microarousals in (p = 0.0493) without significantly changing REM density or the latency to first REM sleep episode. Moreover, the increased accumulation of REM sleep is not at the expense of NREM stage 3 sleep. BDLE further has a unique effect on REM sleep fragmentation (p = 0.0479) over and above that of circadian rhythms phase-shift, indicating a non-circadian effect of BDLE. If these effects can be replicated in clinical populations, this may have a therapeutic potential in disorders characterized by fragmented REM sleep.
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Abstract
Melatonin is a hormonal product of the pineal gland, a fact that is often forgotten. Instead it is promoted as a dietary supplement that will overcome insomnia, as an antioxidant and as a prescription only drug in most countries outside the United States of America and Canada. The aim of this review is to step back and highlight what we know about melatonin following its discovery 60 years ago. What is the role of endogenous melatonin; what does melatonin do to sleep, body temperature, circadian rhythms, the cardiovascular system, reproductive system, endocrine system and metabolism when administered to healthy subjects? When used as a drug/dietary supplement, what safety studies have been conducted? Can we really say melatonin is safe when it has not been systematically studied and many studies show interactions with a wide range of physiological processes? Finally the results of studies investigating the efficacy of melatonin as a drug to alleviate insomnia are critically evaluated. In summary, melatonin is an endogenous pineal gland hormone with specific physiological functions in animals and humans, with its primary role in humans to maintain synchrony of sleep with the day/night cycle. When administered as a drug it affects a wide range of physiological systems and has clinically important drug interactions. With respect to efficacy for treating sleep disorders, melatonin can advance the time of sleep onset but the effect is modest and variable. In children with neurodevelopmental disabilities melatonin appears to have the greatest impact on sleep onset but little effect on sleep efficiency.
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Affiliation(s)
- David J Kennaway
- Robinson Research Institute and Adelaide School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
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12
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Amdisen L, Daugaard S, Vestergaard JM, Vested A, Bonde JP, Vistisen HT, Christoffersen J, Garde AH, Hansen ÅM, Markvart J, Schlünssen V, Kolstad HA. A longitudinal study of morning, evening, and night light intensities and nocturnal sleep quality in a working population. Chronobiol Int 2021; 39:579-589. [PMID: 34903140 DOI: 10.1080/07420528.2021.2010741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
We aimed to investigate whether higher light intensity in the morning is associated with better nocturnal sleep quality and whether higher light intensities in the evening or night have the opposite effect. Light intensity was recorded for 7 consecutive days across the year among 317 indoor and outdoor daytime workers in Denmark (55-56° N) equipped with a personal light recorder. Participants reported sleep quality after each nocturnal sleep. Sleep quality was measured using three parameters; disturbed sleep index, awakening index, and sleep onset latency. Associations between increasing light intensities and sleep quality were analyzed using mixed effects models with participant identity as a random effect. Overall, neither white nor blue light intensities during morning, evening, or night were associated with sleep quality, awakening, or sleep onset latency of the subsequent nocturnal sleep. However, secondary analyses suggested that artificial light during the morning and day contrary to solar light may increase vulnerability to evening light exposure. Altogether, we were not able to confirm that higher morning light intensity significantly improves self-reported sleep quality or that higher evening or night light intensities impair self-reported sleep quality at exposure levels encountered during daily life in a working population in Denmark. This suggests that light intensities alone are not important for sleep quality to a degree that it is distinguishable from other important parameters in daily life settings.
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Affiliation(s)
- Lau Amdisen
- Department of Occupational Medicine, Danish Ramazzini Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Stine Daugaard
- Department of Occupational Medicine, Danish Ramazzini Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Jesper Medom Vestergaard
- Department of Occupational Medicine, Danish Ramazzini Centre, Aarhus University Hospital, Aarhus, Denmark.,Department of Occupational Medicine, Danish Ramazzini Centre, University Research Clinic, Herning, Denmark
| | - Anne Vested
- Department of Occupational Medicine, Danish Ramazzini Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Peter Bonde
- Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark.,Department of Public Health, Section of Social Medicine, Institute of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Helene Tilma Vistisen
- Department of Occupational Medicine, Danish Ramazzini Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Christoffersen
- Knowledge Centre for Daylight, Energy and Indoor Climate, Velux A/s, Velux Group, Hørsholm, Denmark
| | - Anne Helene Garde
- Danish Ministry of Employment, National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Åse Marie Hansen
- Department of Public Health, Section of Social Medicine, Institute of Public Health, University of Copenhagen, Copenhagen, Denmark.,Danish Ministry of Employment, National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Jakob Markvart
- Department of the Built Environment, Division of Energy Efficiency, Indoor Climate and Sustainability of Buildings, Aalborg University, Copenhagen, Denmark
| | - Vivi Schlünssen
- Department of Public Health, Environment, Occupation and Health, Danish Ramazzini Centre, Aarhus University, Aarhus, Denmark
| | - Henrik Albert Kolstad
- Department of Occupational Medicine, Danish Ramazzini Centre, Aarhus University Hospital, Aarhus, Denmark
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Wallace J, Yahia-Cherif L, Gitton C, Hugueville L, Lemaréchal JD, Selmaoui B. Human resting-state EEG and radiofrequency GSM mobile phone exposure: the impact of the individual alpha frequency. Int J Radiat Biol 2021; 98:986-995. [PMID: 34797205 DOI: 10.1080/09553002.2021.2009146] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE With the extensive use of mobile phone (MP), several studies have been realized to investigate the effects of radiofrequency electromagnetic fields (RF-EMF) exposure on brain activity at rest via electroencephalography (EEG), and the most consistent effect has been seen on the alpha band power spectral density (PSD). However, some studies reported an increase or a decrease of the PSD, while others showed no effect. It has been suggested that these differences might partly be due to a variability of the physiological state of the brain between subjects. So, the aim of this study was to investigate the alpha band modulation, exploring the impact of the alpha band frequency ranges applied in the PSD analysis. MATERIALS AND METHODS Twenty-one healthy volunteers took part to the study with a double-blind, randomized and counterbalanced crossover design, during which eyes-open (EO) and eyes-closed (EC) resting-state EEG was recorded. The exposure system was a sham or a real GSM (global system for mobile) 900 MHz MP (pulse modulated at 217 Hz, mean power of 250 mW and 2 W peak, with a maximum specific absorption rate of 0.70 W/kg on 1 g tissue). The experimental protocol presented a baseline recording phase without MP exposure, an exposure phase during which the exposure system was placed against the left ear, and the post-exposure phase without MP. EEG data from baseline and exposure phases were analyzed and PSD was computed for the alpha band in the fixed range of 8-12 Hz and for the individual alpha band frequency range (IAF). RESULTS Results showed a trend in decrease or increase of EEG power of both alpha oscillations during exposure in relation to EC and EO recording conditions, respectively, but not reaching statistical significance. Findings did not provide evidence for a different sensitivity to RF-EMF MP related to individual variability in the frequency of the alpha band. CONCLUSION In conclusion, these results did not show alpha band activity modulation during resting-state under RF-EMF. It might be argued the need of a delay after the exposure in order to appreciate an EEG spectral power modulation related to RF-EMF exposure.
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Affiliation(s)
- Jasmina Wallace
- Department of Experimental Toxicology and Modeling (TEAM), Institut National de l'Environnement Industriel et des Risques (INERIS), Verneuil-en-Halatte, France.,PériTox Laboratory, UMR-I 01 INERIS, Université de Picardie Jules Verne, Amiens, France.,Department of Biological Radiation Effect, Emergent Risk Technologies Unit, French Armed Forces Biomedical Research Institute (IRBA), Bretigny-sur-Orge, France
| | - Lydia Yahia-Cherif
- Centre De NeuroImagerie De Recherche (CENIR), Institut du Cerveau et de la Moelle épinière (ICM), Paris, France.,Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Institut du Cerveau et de la Moelle épinière (ICM), Paris, France
| | - Christophe Gitton
- Centre De NeuroImagerie De Recherche (CENIR), Institut du Cerveau et de la Moelle épinière (ICM), Paris, France.,Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Institut du Cerveau et de la Moelle épinière (ICM), Paris, France
| | - Laurent Hugueville
- Centre De NeuroImagerie De Recherche (CENIR), Institut du Cerveau et de la Moelle épinière (ICM), Paris, France.,Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Institut du Cerveau et de la Moelle épinière (ICM), Paris, France
| | - Jean-Didier Lemaréchal
- Centre De NeuroImagerie De Recherche (CENIR), Institut du Cerveau et de la Moelle épinière (ICM), Paris, France.,Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Institut du Cerveau et de la Moelle épinière (ICM), Paris, France
| | - Brahim Selmaoui
- Department of Experimental Toxicology and Modeling (TEAM), Institut National de l'Environnement Industriel et des Risques (INERIS), Verneuil-en-Halatte, France.,PériTox Laboratory, UMR-I 01 INERIS, Université de Picardie Jules Verne, Amiens, France
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14
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Wallace J, Yahia-Cherif L, Gitton C, Hugueville L, Lemaréchal JD, Selmaoui B. Modulation of magnetoencephalography alpha band activity by radiofrequency electromagnetic field depicted in sensor and source space. Sci Rep 2021; 11:23403. [PMID: 34862418 PMCID: PMC8642443 DOI: 10.1038/s41598-021-02560-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 11/12/2021] [Indexed: 01/05/2023] Open
Abstract
Several studies reported changes in spontaneous electroencephalogram alpha band activity related to radiofrequency electromagnetic fields, but findings showed both an increase and a decrease of its spectral power or no effect. Here, we studied the alpha band modulation after 900 MHz mobile phone radiofrequency exposure and localized cortical regions involved in these changes, via a magnetoencephalography (MEG) protocol with healthy volunteers in a double-blind, randomized, counterbalanced crossover design. MEG was recorded during eyes open and eyes closed resting-state before and after radiofrequency exposure. Potential confounding factors, known to affect alpha band activity, were assessed as control parameters to limit bias. Entire alpha band, lower and upper alpha sub-bands MEG power spectral densities were estimated in sensor and source space. Biochemistry assays for salivary biomarkers of stress (cortisol, chromogranin-A, alpha amylase), heart rate variability analysis and high-performance liquid chromatography for salivary caffeine concentration were realized. Results in sensor and source space showed a significant modulation of MEG alpha band activity after the radiofrequency exposure, with different involved cortical regions in relation to the eyes condition, probably because of different attention level with open or closed eyes. None of the control parameters reported a statistically significant difference between experimental sessions.
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Affiliation(s)
- Jasmina Wallace
- Department of Experimental Toxicology and Modeling (TEAM), Institut National de l'Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP 2, 60550, Verneuil-en-Halatte, France
- PériTox Laboratory, UMR-I 01 INERIS, Université de Picardie Jules Verne, 80025, Amiens, France
| | - Lydia Yahia-Cherif
- Centre De NeuroImagerie De Recherche (CENIR), Institut du Cerveau et de la Moelle épinière (ICM), 75013, Paris, France
- Inserm U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière (ICM), Sorbonne Université, 75013, Paris, France
| | - Christophe Gitton
- Centre De NeuroImagerie De Recherche (CENIR), Institut du Cerveau et de la Moelle épinière (ICM), 75013, Paris, France
- Inserm U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière (ICM), Sorbonne Université, 75013, Paris, France
| | - Laurent Hugueville
- Centre De NeuroImagerie De Recherche (CENIR), Institut du Cerveau et de la Moelle épinière (ICM), 75013, Paris, France
- Inserm U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière (ICM), Sorbonne Université, 75013, Paris, France
| | - Jean-Didier Lemaréchal
- Centre De NeuroImagerie De Recherche (CENIR), Institut du Cerveau et de la Moelle épinière (ICM), 75013, Paris, France
- Inserm U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière (ICM), Sorbonne Université, 75013, Paris, France
| | - Brahim Selmaoui
- Department of Experimental Toxicology and Modeling (TEAM), Institut National de l'Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP 2, 60550, Verneuil-en-Halatte, France.
- PériTox Laboratory, UMR-I 01 INERIS, Université de Picardie Jules Verne, 80025, Amiens, France.
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15
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Koller DP, Kasanin V, Flynn-Evans EE, Sullivan JP, Dijk DJ, Czeisler CA, Barger LK. Altered sleep spindles and slow waves during space shuttle missions. NPJ Microgravity 2021; 7:48. [PMID: 34795291 PMCID: PMC8602337 DOI: 10.1038/s41526-021-00177-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 10/07/2021] [Indexed: 11/09/2022] Open
Abstract
Sleep deficiencies and associated performance decrements are common among astronauts during spaceflight missions. Previously, sleep in space was analyzed with a focus on global measures while the intricate structure of sleep oscillations remains largely unexplored. This study extends previous findings by analyzing how spaceflight affects characteristics of sleep spindles and slow waves, two sleep oscillations associated with sleep quality and quantity, in four astronauts before, during and after two Space Shuttle missions. Analysis of these oscillations revealed significantly increased fast spindle density, elevated slow spindle frequency, and decreased slow wave amplitude in space compared to on Earth. These results reflect sleep characteristics during spaceflight on a finer electrophysiological scale and provide an opportunity for further research on sleep in space.
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Affiliation(s)
- Dominik P Koller
- Advanced Concepts Team, European Space Agency, ESTEC, Noordwijk, The Netherlands.
| | - Vida Kasanin
- Advanced Concepts Team, European Space Agency, ESTEC, Noordwijk, The Netherlands
| | - Erin E Flynn-Evans
- Fatigue Countermeasures Laboratory, Human Systems Integration Division, Exploration Technology Directorate, NASA Ames Research Center, Moffett Field, CA, USA
| | - Jason P Sullivan
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Derk-Jan Dijk
- Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
- UK Dementia Research Institute Care Research and Technology Centre, Imperial College London and the University of Surrey, Guildford, UK
| | - Charles A Czeisler
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Laura K Barger
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
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16
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Bigalke JA, Greenlund IM, Nicevski JR, Carter JR. Effect of evening blue light blocking glasses on subjective and objective sleep in healthy adults: A randomized control trial. Sleep Health 2021; 7:485-490. [PMID: 33707105 DOI: 10.1016/j.sleh.2021.02.004] [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: 10/07/2020] [Revised: 02/01/2021] [Accepted: 02/08/2021] [Indexed: 02/03/2023]
Abstract
OBJECTIVES Evening blue light has been shown to suppress melatonin, which can negatively impact sleep quality. The impact of evening blue light blocking (BLB) interventions on sleep remains ambiguous due to lack of randomized control trials. The present study tests the hypothesis that BLB glasses improve subjective and objective sleep in a population of healthy adults. DESIGN Two-week, randomized, controlled, crossover design. SETTING At-home testing of individuals in Michigan and Montana. PARTICIPANTS Twenty healthy adults (11 men, 9 women, age: 32 ± 12, body mass index: 28 ± 4 kg/m2). INTERVENTION Following a 1-week run-in baseline (ie, no glasses), participants were randomized to 1-week of BLB or control (ie, clear lens) glasses. Upon finishing the 1-week intervention, participants crossed over to the opposite condition. In both conditions, glasses were worn for 7 consecutive days from 6 PM until bedtime. MEASUREMENTS Objective sleep parameters were obtained using wrist actigraphy. Subjective sleep measures were assessed using sleep diaries. Karolinska Sleep Diaries were used to assess perceived sleep quality. RESULTS BLB reduced subjective sleep onset (21 ± 28 vs 24 ± 21 minute, P = .033) and awakenings (1.6 ± 1.0 vs 2.2 ± 1.0 awakenings, P = .019) compared to the control condition. In contrast, objective measures of sleep were not significantly impacted. In fact, our primary outcome variable of total sleep time (TST) tended to be paradoxically shorter in the BLB condition for both subjective (468 ± 45 vs 480 ± 48 minute, P = .066) and objective (433 ± 40 vs 449 ± 39 minute, P = .075) TST. CONCLUSIONS Blue light blocking glasses did not improve objective measures of sleep time or quality in healthy adults.
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Affiliation(s)
- Jeremy A Bigalke
- Department of Health and Human Development, Montana State University, Bozeman, Montana, USA; Department of Psychology, Montana State University, Bozeman, Montana, USA
| | - Ian M Greenlund
- Department of Health and Human Development, Montana State University, Bozeman, Montana, USA; Department of Psychology, Montana State University, Bozeman, Montana, USA
| | - Jennifer R Nicevski
- Department of Health and Human Development, Montana State University, Bozeman, Montana, USA
| | - Jason R Carter
- Department of Health and Human Development, Montana State University, Bozeman, Montana, USA; Department of Psychology, Montana State University, Bozeman, Montana, USA.
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17
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Modulation of recognition memory performance by light and its relationship with cortical EEG theta and gamma activities. Biochem Pharmacol 2021; 191:114404. [PMID: 33412102 PMCID: PMC8363935 DOI: 10.1016/j.bcp.2020.114404] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 12/26/2022]
Abstract
Acute exposure to light exerts widespread effects on physiology, in addition to its key role in photoentrainment. Although the modulatory effect of light on physiological arousal is well demonstrated in mice, its effect on memory performance is inconclusive, as the direction of the effect depends on the nature of the behavioural task employed and/or the type of stimulus utilised. Moreover, in all rodent studies that reported significant effects of light on performance, brain activity was not assessed during the task and thus it is unclear how brain activity was modulated by light or the exact relationship between light-modulated brain activity and performance. Here we examine the modulatory effects of light of varying intensities on recognition memory performance and frontoparietal waking electroencephalography (EEG) in mice using the spontaneous recognition memory task. We report a light-intensity-dependent disruptive effect on recognition memory performance at the group level, but inspection of individual-level data indicates that light-intensity-dependent facilitation is observed in some cases. Using linear mixed-effects models, we then demonstrate that EEG fast theta (θ) activity at the time of encoding negatively predicts recognition memory performance, whereas slow gamma (γ) activity at the time of retrieval positively predicts performance. These relationships between θ/γ activity and performance are strengthened by increasing light intensity. Thus, light modulates θ and γ band activities involved in attentional and mnemonic processes, thereby affecting recognition memory performance. However, extraneous factors including the phase of the internal clock at which light is presented and homeostatic sleep pressure may determine how photic input is translated into behavioural performance.
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18
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Sletten TL, Raman B, Magee M, Ferguson SA, Kennaway DJ, Grunstein RR, Lockley SW, Rajaratnam SMW. A Blue-Enriched, Increased Intensity Light Intervention to Improve Alertness and Performance in Rotating Night Shift Workers in an Operational Setting. Nat Sci Sleep 2021; 13:647-657. [PMID: 34079409 PMCID: PMC8163632 DOI: 10.2147/nss.s287097] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/04/2021] [Indexed: 12/20/2022] Open
Abstract
PURPOSE This study examined the efficacy of a lighting intervention that increased both light intensity and short-wavelength (blue) light content to improve alertness, performance and mood in night shift workers in a chemical plant. PATIENTS AND METHODS During rostered night shifts, 28 workers (46.0±10.8 years; 27 male) were exposed to two light conditions each for two consecutive nights (~19:00-07:00 h) in a counterbalanced repeated measures design: traditional-spectrum lighting set at pre-study levels (43 lux, 4000 K) versus higher intensity, blue-enriched lighting (106 lux, 17,000 K), equating to a 4.5-fold increase in melanopic illuminance (24 to 108 melanopic illuminance). Participants completed the Karolinska Sleepiness Scale, subjective mood ratings, and the Psychomotor Vigilance Task (PVT) every 2-4 hours during the night shift. RESULTS A significant main effect of time indicated KSS, PVT mean reaction time, number of PVT lapses (reaction times > 500 ms) and subjective tension, misery and depression worsened over the course of the night shift (p<0.05). Percentage changes in KSS (p<0.05, partial η2=0.14) and PVT mean reaction time (p<0.05, partial η2=0.19) and lapses (p<0.05, partial η2=0.17) in the middle and end of night shift, expressed relative to start of shift, were significantly improved during the lighting intervention compared to the traditional lighting condition. Self-reported mood did not significantly differ between conditions (p>0.05). CONCLUSION Our findings, showing improvements in alertness and performance with exposure to blue-enriched, increased intensity light, provide support for light to be used as a countermeasure for impaired alertness in night shift work settings.
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Affiliation(s)
- Tracey L Sletten
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Bhairavi Raman
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Michelle Magee
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Sally A Ferguson
- Central Queensland University, Appleton Institute, Goodwood, SA, Australia
| | - David J Kennaway
- Robinson Research Institute, School of Medicine, Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, SA, Australia
| | - Ronald R Grunstein
- Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia.,Department of Respiratory & Sleep Medicine, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - Steven W Lockley
- 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
| | - Shantha M W Rajaratnam
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.,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
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19
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Wallace J, Selmaoui B. Effect of mobile phone radiofrequency signal on the alpha rhythm of human waking EEG: A review. ENVIRONMENTAL RESEARCH 2019; 175:274-286. [PMID: 31146099 DOI: 10.1016/j.envres.2019.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 05/14/2023]
Abstract
In response to the exponential increase in mobile phone use and the resulting increase in exposure to radiofrequency electromagnetic fields (RF-EMF), there have been several studies to investigate via electroencephalography (EEG) whether RF-EMF exposure affects brain activity. Data in the literature have shown that exposure to radiofrequency signals modifies the waking EEG with the main effect on the alpha band frequency (8-13 Hz). However, some studies have reported an increase in alpha band power, while others have shown a decrease, and other studies showed no effect on EEG power. Given that changes in the alpha amplitude are associated with attention and some cognitive aspects of human behavior, researchers deemed necessary to look whether alpha rhythm was modulated under RF-EMF exposure. The present review aims at comparing and discussing the main findings obtained so far regarding RF-EMF effects on alpha rhythm of human waking spontaneous EEG, focusing on differences in protocols between studies, which might explain the observed discrepancies and inconclusive results.
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Affiliation(s)
- Jasmina Wallace
- Experimental Toxicology Unit, National Institute of Industrial Environment and Risks (INERIS), Verneuil-en-Halatte, France; PériTox Laboratory, UMR-I-01, Faculty of Medicine, University of Picardy Jules Verne, Amiens, France
| | - Brahim Selmaoui
- Experimental Toxicology Unit, National Institute of Industrial Environment and Risks (INERIS), Verneuil-en-Halatte, France; PériTox Laboratory, UMR-I-01, Faculty of Medicine, University of Picardy Jules Verne, Amiens, France.
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20
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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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Mallinson DC, Kamenetsky ME, Hagen EW, Peppard PE. Subjective sleep measurement: comparing sleep diary to questionnaire. Nat Sci Sleep 2019; 11:197-206. [PMID: 31686932 PMCID: PMC6752706 DOI: 10.2147/nss.s217867] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 08/06/2019] [Indexed: 01/07/2023] Open
Abstract
PURPOSE The sleep diary is the gold standard of self-reported sleep duration, but its comparability to sleep questionnaires is uncertain. The purpose of this study was to compare self-reported sleep duration between a sleep diary and a sleep questionnaire and to test whether sleep-related disorders were associated with diary-questionnaire differences in sleep duration. PARTICIPANTS AND METHODS We compared self-reported sleep duration from 5,432 questionnaire-sleep diary pairs in a longitudinal cohort of 1,516 adults. Participants reported sleep information in seven-day sleep diaries and in questionnaires. Research staff abstracted average sleep durations for three time periods (overall; weekday; weekend) from diaries and questionnaires. For each time period, we evaluated diary-questionnaire differences in sleep duration with Welch's two-sample t-tests. Using linear mixed effects regression, we regressed overall diary-questionnaire sleep duration difference on several participant characteristics: reporting any insomnia symptoms, having sleep apnea, sex, body mass index, smoking status, Short Form-12 Physical Health Composite Score, and Short Form-12 Mental Health Composite Score. RESULTS The average diary-reported overall sleep duration (7.76 hrs) was longer than that of the questionnaire (7.07 hrs) by approximately 41 mins (0.69 hrs, 95% confidence interval: 0.62, 0.76 hrs). Results were consistent across weekday- and weekend-specific differences. Demographic-adjusted linear mixed effects models tested whether insomnia symptoms or sleep apnea were associated with diary-questionnaire differences in sleep duration. Insomnia symptoms were associated with a 17 min longer duration on the diary relative to the questionnaire (β=0.28 hrs, 95% confidence interval: 0.22, 0.33 hrs), but sleep apnea was not significantly associated with diary-questionnaire difference. Female sex was associated with greater diary-questionnaire duration differences, whereas better self-reported health was associated with lesser differences. CONCLUSION Diaries and questionnaires are somewhat disparate methods of assessing subjective sleep duration, although diaries report longer duration relative to questionnaires, and insomnia symptoms may contribute to greater perceived differences.
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Affiliation(s)
- David C Mallinson
- Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Maria E Kamenetsky
- Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Erika W Hagen
- Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Paul E Peppard
- Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
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22
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Dautovich ND, Schreiber DR, Imel JL, Tighe CA, Shoji KD, Cyrus J, Bryant N, Lisech A, O'Brien C, Dzierzewski JM. A systematic review of the amount and timing of light in association with objective and subjective sleep outcomes in community-dwelling adults. Sleep Health 2018; 5:31-48. [PMID: 30670164 DOI: 10.1016/j.sleh.2018.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 09/12/2018] [Accepted: 09/17/2018] [Indexed: 12/01/2022]
Abstract
Light is considered the dominant environmental cue, or zeitgeber, influencing the sleep-wake cycle. Despite recognizing the importance of light for our well-being, less is known about the specific conditions under which light is optimally associated with better sleep. Therefore, a systematic review was conducted to examine the association between the amount and timing of light exposure in relation to sleep outcomes in healthy, community-dwelling adults. A systematic search was conducted of four databases from database inception to June 2016. In total, 45 studies met the review eligibility criteria with generally high study quality excepting for the specification of eligibility criteria and the justification of sample size. The majority of studies involved experimental manipulation of light (n = 32) vs observational designs (n = 13). Broad trends emerged suggesting that (1) bright light (>1000 lux) has positive implications for objectively assessed sleep outcomes compared to dim (<100 lux) and moderate light (100-1000 lux) and (2) bright light (>1000 lux) has positive implications for subjectively assessed sleep outcomes compared to moderate light (100-1000 lux). Effects due to the amount of light are moderated by the timing of light exposure such that, for objectively assessed sleep outcomes, brighter morning and evening light exposure are consistent with a shift in the timing of the sleep period to earlier and later in the day, respectively. For subjectively assessed sleep outcomes, brighter light delivered in the morning was associated with self-reported sleep improvements and brighter evening light exposure was associated with worse self-reported sleep.
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Affiliation(s)
- Natalie D Dautovich
- Psychology Department, Virginia Commonwealth University, 800 W Franklin St, Room 203, PO Box 842018, Richmond, VA 23284-2018.
| | - Dana R Schreiber
- Psychology Department, Virginia Commonwealth University, 806 W Franklin St, PO Box 842018, Richmond, VA 23284-2018
| | - Janna L Imel
- Psychology Department, Virginia Commonwealth University, 806 W Franklin St, PO Box 842018, Richmond, VA 23284-2018
| | - Caitlan A Tighe
- Department of Psychology, University of Alabama, Box 870348, The University of Alabama, Tuscaloosa, AL 35487-0348
| | - Kristy D Shoji
- South Texas Veterans Healthcare System, 7400 Merton Minter, San Antonio, TX 78229
| | - John Cyrus
- Tompkins-McCaw Library, Virginia Commonwealth University, 509 N 12th St, Box 980582, Richmond, VA 23298-0582
| | - Nita Bryant
- James Branch Cabell Library, Virginia Commonwealth University, 901 Park Ave, Box 842033,Richmond, VA 23284-2033
| | - Andrew Lisech
- Psychology Department, Virginia Commonwealth University, 806 W Franklin St, PO Box 842018, Richmond, VA 23284-2018
| | - Chris O'Brien
- Psychology Department, Chatham University, Woodland Rd, Pittsburgh, PA 15232
| | - Joseph M Dzierzewski
- Psychology Department, Virginia Commonwealth University, 806 W Franklin St, PO Box 842018, Richmond, VA 23284-2018
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23
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Łaszewska K, Goroncy A, Weber P, Pracki T, Tafil-Klawe M, Pracka D, Złomańczuk P. Daytime Acute Non-Visual Alerting Response in Brain Activity Occurs as a Result of Short- and Long-Wavelengths of Light. J PSYCHOPHYSIOL 2018. [DOI: 10.1027/0269-8803/a000199] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract. Very recent preliminary findings concerning the alerting capacities of light stimulus with long-wavelengths suggest the existence of neural pathways other than melatonin suppression that trigger the nonvisual response. Though the nonvisual effects of light during the daytime have not been investigated thoroughly, they are definitely worth investigating. The purpose of the present study is to enrich existing evidence by describing how quantitative electroencephalography (EEG) signal analysis can give insight into the measurement of the acute nonvisual response observed in brain states generated during daytime exposure to light (when melatonin secretion is negligible). EEG changes were assessed in 19 subjects during the daytime while being exposed to both short- (blue, 72 μW/cm2) and long-wavelength (red, 18 μW/cm2) radiation. We showed that artificial light stimulus as low as 40 lux decreases the synchronization in the upper theta, lower alpha, and upper alpha EEG activity spectrum. The direction of change was consistent with an increased level of alertness. We can conclude that EEG analysis is an indicator of the acute nonvisual response to daytime light. Surprisingly, the response was more spread over the scalp during exposure to red light than to blue light. According to our study, the response to long-wavelength stimulus that inhibits sleepiness, thereby inducing alertness, also takes place at the bright part of the 24-hr day when human beings are naturally predisposed to be exposed to a high level of sunlight: between 12 and 4 PM. The absorption spectrum of the nonvisual system seems to have different characteristics than was previously suspected: it is not dominated by the short-wavelengths, but involves long-wavelengths. Since we observed the predominance of the red-light alerting effect over the blue-light in this experiment, we conclude that more than one mechanism, beyond the melatonin pathway, must be involved.
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Affiliation(s)
- Kamila Łaszewska
- Department of Physiology, Nicolaus Copernicus University, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Poland
| | - Agnieszka Goroncy
- Department of Probability Theory and Stochastic Analysis, Faculty of Mathematics and Computer Science, Nicolaus Copernicus University, Toruń, Poland
| | - Piotr Weber
- Department of Atomic, Molecular and Optical Physics, Gdańsk University of Technology, Gdańsk, Poland
| | - Tadeusz Pracki
- Department of Physiology, Nicolaus Copernicus University, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Poland
| | - Małgorzata Tafil-Klawe
- Department of Physiology, Nicolaus Copernicus University, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Poland
| | - Daria Pracka
- Department of Physiology, Nicolaus Copernicus University, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Poland
| | - Piotr Złomańczuk
- Department of Physiology, Nicolaus Copernicus University, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Poland
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24
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Fisk AS, Tam SKE, Brown LA, Vyazovskiy VV, Bannerman DM, Peirson SN. Light and Cognition: Roles for Circadian Rhythms, Sleep, and Arousal. Front Neurol 2018; 9:56. [PMID: 29479335 PMCID: PMC5811463 DOI: 10.3389/fneur.2018.00056] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 01/22/2018] [Indexed: 01/12/2023] Open
Abstract
Light exerts a wide range of effects on mammalian physiology and behavior. As well as synchronizing circadian rhythms to the external environment, light has been shown to modulate autonomic and neuroendocrine responses as well as regulating sleep and influencing cognitive processes such as attention, arousal, and performance. The last two decades have seen major advances in our understanding of the retinal photoreceptors that mediate these non-image forming responses to light, as well as the neural pathways and molecular mechanisms by which circadian rhythms are generated and entrained to the external light/dark (LD) cycle. By contrast, our understanding of the mechanisms by which lighting influences cognitive processes is more equivocal. The effects of light on different cognitive processes are complex. As well as the direct effects of light on alertness, indirect effects may also occur due to disrupted circadian entrainment. Despite the widespread use of disrupted LD cycles to study the role circadian rhythms on cognition, the different experimental protocols used have subtly different effects on circadian function which are not always comparable. Moreover, these protocols will also disrupt sleep and alter physiological arousal, both of which are known to modulate cognition. Studies have used different assays that are dependent on different cognitive and sensory processes, which may also contribute to their variable findings. Here, we propose that studies addressing the effects of different lighting conditions on cognitive processes must also account for their effects on circadian rhythms, sleep, and arousal if we are to fully understand the physiological basis of these responses.
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Affiliation(s)
- Angus S Fisk
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Shu K E Tam
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Laurence A Brown
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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25
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Exposure to Night-Time Traffic Noise, Melatonin-Regulating Gene Variants and Change in Glycemia in Adults. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14121492. [PMID: 29194408 PMCID: PMC5750910 DOI: 10.3390/ijerph14121492] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 11/24/2017] [Accepted: 11/29/2017] [Indexed: 11/16/2022]
Abstract
Traffic noise has been linked to diabetes, with limited understanding of its mechanisms. We hypothesize that night-time road traffic noise (RTN) may impair glucose homeostasis through circadian rhythm disturbances. We prospectively investigated the relationship between residential night-time RTN and subsequent eight-year change in glycosylated hemoglobin (ΔHbA1c) in 3350 participants of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA), adjusting for diabetes risk factors and air pollution levels. Annual average RTN (Lnight) was assigned to participants in 2001 using validated Swiss noise models. HbA1c was measured in 2002 and 2011 using liquid chromatography. We applied mixed linear models to explore RTN–ΔHbA1c association and its modification by a genetic risk score of six common circadian-related MTNR1B variants (MGRS). A 10 dB difference in RTN was associated with a 0.02% (0.003–0.04%) increase in mean ΔHbA1c in 2142 non-movers. RTN–ΔHbA1c association was modified by MGRS among diabetic participants (Pinteraction = 0.001). A similar trend in non-diabetic participants was non-significant. Among the single variants, we observed strongest interactions with rs10830963, an acknowledged diabetes risk variant also implicated in melatonin profile dysregulation. Night-time RTN may impair glycemic control, especially in diabetic individuals, through circadian rhythm disturbances. Experimental sleep studies are needed to test whether noise control may help individuals to attain optimal glycemic levels.
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26
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Sletten TL, Ftouni S, Nicholas CL, Magee M, Grunstein RR, Ferguson S, Kennaway DJ, O'Brien D, Lockley SW, Rajaratnam SMW. Randomised controlled trial of the efficacy of a blue-enriched light intervention to improve alertness and performance in night shift workers. Occup Environ Med 2017. [PMID: 28630378 DOI: 10.1136/oemed-2016-103818] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES Night workers often experience high levels of sleepiness due to misalignment of the sleep-wake cycle from the circadian pacemaker, in addition to acute and chronic sleep loss. Exposure to light, in particular short wavelength light, can improve alertness and neurobehavioural performance. This randomised controlled trial examined the efficacy of blue-enriched polychromatic light to improve alertness and neurobehavioural performance in night workers. DESIGN Participants were 71 night shift workers (42 males; 32.8±10.5 years) who worked at least 6 hours between 22:00 and 08:00 hours. Sleep-wake logs and wrist actigraphy were collected for 1-3 weeks, followed by 48-hour urine collection to measure the circadian 6-sulphatoxymelatonin (aMT6s) rhythm. On the night following at least two consecutive night shifts, workers attended a simulated night shift in the laboratory which included subjective and objective assessments of sleepiness and performance. Workers were randomly assigned for exposure to one of two treatment conditions from 23:00 hours to 07:00 hours: blue-enriched white light (17 000 K, 89 lux; n=36) or standard white light (4000 K, 84 lux; n=35). RESULTS Subjective and objective sleepiness increased during the night shift in both light conditions (p<0.05, ηp2=0.06-0.31), but no significant effects of light condition were observed. The 17 000 K light, however, did improve subjective sleepiness relative to the 4000 K condition when light exposure coincided with the time of the aMT6s peak (p<0.05, d=0.41-0.60). CONCLUSION This study suggests that, while blue-enriched light has potential to improve subjective sleepiness in night shift workers, further research is needed in the selection of light properties to maximise the benefits. TRIAL REGISTRATION NUMBER The Australian New Zealand Clinical Trials Registry ACTRN12610000097044 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=320845&isReview=true).
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Affiliation(s)
- Tracey L Sletten
- Monash Institute of Cognitive and Clinical Neurosciences and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.,CRC for Alertness, Safety and Productivity, Clayton, Victoria, Australia
| | - Suzanne Ftouni
- Monash Institute of Cognitive and Clinical Neurosciences and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.,CRC for Alertness, Safety and Productivity, Clayton, Victoria, Australia
| | - Christian L Nicholas
- Melbourne School of Psychological Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Michelle Magee
- Monash Institute of Cognitive and Clinical Neurosciences and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.,CRC for Alertness, Safety and Productivity, Clayton, Victoria, Australia
| | - Ronald R Grunstein
- CRC for Alertness, Safety and Productivity, Clayton, Victoria, Australia.,Woolcock Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia.,Department of Respiratory & Sleep Medicine, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Sally Ferguson
- Appleton Institute, Central Queensland University, Wayville, South Australia, Australia
| | - David J Kennaway
- Robinson Research Institute, School of Medicine, Discipline of Obstetrics and Gynaecology, University of Adelaide, Adelaide, South Australia, Australia
| | - Darren O'Brien
- Woolcock Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia.,Sydney Nursing School, University of Sydney, Sydney, New South Wales, Australia
| | - Steven W Lockley
- Monash Institute of Cognitive and Clinical Neurosciences and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.,CRC for Alertness, Safety and Productivity, Clayton, Victoria, Australia.,Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Shantha M W Rajaratnam
- Monash Institute of Cognitive and Clinical Neurosciences and School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia.,CRC for Alertness, Safety and Productivity, Clayton, Victoria, Australia.,Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
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27
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Green A, Cohen-Zion M, Haim A, Dagan Y. Evening light exposure to computer screens disrupts human sleep, biological rhythms, and attention abilities. Chronobiol Int 2017; 34:855-865. [DOI: 10.1080/07420528.2017.1324878] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- A. Green
- The Israeli Center for Interdisciplinary Research in Chronobiology, University of Haifa, Mount Carmel, Haifa, Israel
- The Sleep and Fatigue Institute, Assuta Medical Center, Tel Aviv, Israel
| | - M. Cohen-Zion
- The Sleep and Fatigue Institute, Assuta Medical Center, Tel Aviv, Israel
- School of Behavioral Sciences, The Academic College of Tel Aviv-Jaffa, Tel Aviv-Jaffa, Israel
| | - A. Haim
- The Israeli Center for Interdisciplinary Research in Chronobiology, University of Haifa, Mount Carmel, Haifa, Israel
- The Research Institute of Applied Chronobiology, The Academic College of Tel-Hai, Tel Hai, Israel
- The Department of Human Biology, University of Haifa, Mount Carmel, Haifa, Israel
| | - Y. Dagan
- The Israeli Center for Interdisciplinary Research in Chronobiology, University of Haifa, Mount Carmel, Haifa, Israel
- The Sleep and Fatigue Institute, Assuta Medical Center, Tel Aviv, Israel
- The Research Institute of Applied Chronobiology, The Academic College of Tel-Hai, Tel Hai, Israel
- The Department of Human Biology, University of Haifa, Mount Carmel, Haifa, Israel
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28
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Tam SKE, Hasan S, Hughes S, Hankins MW, Foster RG, Bannerman DM, Peirson SN. Modulation of recognition memory performance by light requires both melanopsin and classical photoreceptors. Proc Biol Sci 2016; 283:20162275. [PMID: 28003454 PMCID: PMC5204172 DOI: 10.1098/rspb.2016.2275] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 11/14/2016] [Indexed: 01/26/2023] Open
Abstract
Acute light exposure exerts various effects on physiology and behaviour. Although the effects of light on brain network activity in humans are well demonstrated, the effects of light on cognitive performance are inconclusive, with the size, as well as direction, of the effect depending on the nature of the task. Similarly, in nocturnal rodents, bright light can either facilitate or disrupt performance depending on the type of task employed. Crucially, it is unclear whether the effects of light on behavioural performance are mediated via the classical image-forming rods and cones or the melanopsin-expressing photosensitive retinal ganglion cells. Here, we investigate the modulatory effects of light on memory performance in mice using the spontaneous object recognition task. Importantly, we examine which photoreceptors are required to mediate the effects of light on memory performance. By using a cross-over design, we show that object recognition memory is disrupted when the test phase is conducted under a bright light (350 lux), regardless of the light level in the sample phase (10 or 350 lux), demonstrating that exposure to a bright light at the time of test, rather than at the time of encoding, impairs performance. Strikingly, the modulatory effect of light on memory performance is completely abolished in both melanopsin-deficient and rodless-coneless mice. Our findings provide direct evidence that melanopsin-driven and rod/cone-driven photoresponses are integrated in order to mediate the effect of light on memory performance.
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Affiliation(s)
- Shu K E Tam
- Sleep and Circadian Neuroscience Institute (Nuffield Department of Clinical Neurosciences), Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
- Department of Experimental Psychology, Oxford University, Tinbergen Building, 9 South Parks Road, Oxford OX1 3UD, UK
| | - Sibah Hasan
- Sleep and Circadian Neuroscience Institute (Nuffield Department of Clinical Neurosciences), Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | - Steven Hughes
- Sleep and Circadian Neuroscience Institute (Nuffield Department of Clinical Neurosciences), Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | - Mark W Hankins
- Sleep and Circadian Neuroscience Institute (Nuffield Department of Clinical Neurosciences), Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | - Russell G Foster
- Sleep and Circadian Neuroscience Institute (Nuffield Department of Clinical Neurosciences), Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
| | - David M Bannerman
- Department of Experimental Psychology, Oxford University, Tinbergen Building, 9 South Parks Road, Oxford OX1 3UD, UK
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute (Nuffield Department of Clinical Neurosciences), Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK
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29
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Popok DW, West CR, Hubli M, Currie KD, Krassioukov AV. Characterizing the Severity of Autonomic Cardiovascular Dysfunction after Spinal Cord Injury Using a Novel 24 Hour Ambulatory Blood Pressure Analysis Software. J Neurotrauma 2016; 34:559-566. [PMID: 27573583 DOI: 10.1089/neu.2016.4573] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cardiovascular disease is one of the leading causes of morbidity and mortality in the spinal cord injury (SCI) population. SCI may disrupt autonomic cardiovascular homeostasis, which can lead to persistent hypotension, irregular diurnal rhythmicity, and the development of autonomic dysreflexia (AD). There is currently no software available to perform automated detection and evaluation of cardiovascular autonomic dysfunction(s) such as those generated from 24 h ambulatory blood pressure monitoring (ABPM) recordings in the clinical setting. The objective of this study is to compare the efficacy of a novel 24 h ABPM Autonomic Dysfunction Detection Software against manual detection and to use the software to demonstrate the relationships between level of injury and the degree of autonomic cardiovascular impairment in a large cohort of individuals with SCI. A total of 46 individuals with cervical (group 1, n = 37) or high thoracic (group 2, n = 9) SCI participated in the study. Outcome measures included the frequency and severity of AD, frequency of hypotensive events, and diurnal variations in blood pressure and heart rate. There was good agreement between the software and manual detection of AD events (Bland-Altman limits of agreement = ±1.458 events). Cervical SCI presented with more frequent (p = 0.0043) and severe AD (p = 0.0343) than did high thoracic SCI. Cervical SCI exhibited higher systolic and diastolic blood pressure during the night and lower heart rate during the day than high thoracic SCI. In conclusion, our ABPM AD Detection Software was equally as effective in detecting the frequency and severity of AD and hypotensive events as manual detection, suggesting that this software can be used in the clinical setting to expedite ABPM analyses.
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Affiliation(s)
- David W Popok
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Christopher R West
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,2 School of Kinesiology, Faculty of Education, University of British Columbia , Vancouver, British Columbia, Canada
| | - Michele Hubli
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Katharine D Currie
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Andrei V Krassioukov
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,3 Faculty of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia , Vancouver, British Columbia, Canada .,4 GF Strong Rehabilitation Centre , Vancouver Coastal Health, Vancouver, British Columbia, Canada
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30
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Effects of light wavelength on MEG ERD/ERS during a working memory task. Int J Psychophysiol 2016; 104:10-6. [PMID: 27040560 DOI: 10.1016/j.ijpsycho.2016.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 03/29/2016] [Accepted: 03/29/2016] [Indexed: 11/23/2022]
Abstract
We investigated the effects of light wavelengths on cortical oscillatory activity associated with working memory processes. Cortical activity responses were measured using magnetoencephalography (MEG) while participants performed an auditory Sternberg memory task during exposure to light of different wavelength. Each trial of the memory task consisted of four words presented as a memory set and one word presented as a probe. All words were presented audibly. Participants were instructed to indicate whether the probe word was or was not presented within the memory set. A total of 90 trials were conducted under the light exposure. Event-related synchronization (ERS) and event-related desynchronization responses in the alpha frequency range during the task were analyzed. Results showed that, during memory encoding, ERS responses were significantly greater in the short-wavelength (blue) light condition than in the middle-wavelength (green) light condition, approximately 20-30min after the onset of light exposure. Behavioral performance was very high throughout the experiment and there was no difference between the light conditions. Although the light effects were not observed in behavior, the result of ERS suggests that 20-30min of exposure to blue light enhances cortical activity related to active memory maintenance and/or attention to auditory stimuli.
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31
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Youngstedt SD, Goff EE, Reynolds AM, Kripke DF, Irwin MR, Bootzin RR, Khan N, Jean-Louis G. Has adult sleep duration declined over the last 50+ years? Sleep Med Rev 2015; 28:69-85. [PMID: 26478985 DOI: 10.1016/j.smrv.2015.08.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 08/09/2015] [Accepted: 08/13/2015] [Indexed: 01/01/2023]
Abstract
The common assumption that population sleep duration has declined in the past few decades has not been supported by recent reviews, which have been limited to self-reported data. The aim of this review was to assess whether there has been a reduction in objectively recorded sleep duration over the last 50+ years. The literature was searched for studies published from 1960 to 2013, which assessed objective sleep duration (total sleep time (TST)) in healthy normal-sleeping adults. The search found 168 studies that met inclusion criteria, with 257 data points representing 6052 individuals ages 18-88 y. Data were assessed by comparing the regression lines of age vs. TST in studies conducted between 1960 and 1989 vs. 1990-2013. Weighted regression analyses assessed the association of year of study with age-adjusted TST across all data points. Regression analyses also assessed the association of year of study with TST separately for 10-y age categories (e.g., ages 18-27 y), and separately for polysomnographic and actigraphic data, and for studies involving a fixed sleep schedule and participants' customary sleep schedules. Analyses revealed no significant association of sleep duration with study year. The results are consistent with recent reviews of subjective data, which have challenged the notion of a modern epidemic of insufficient sleep.
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Affiliation(s)
- Shawn D Youngstedt
- College of Nursing and Health Innovation, College of Health Solutions, Arizona State University, Phoenix, AZ, USA.
| | - Eric E Goff
- Department of Biological Sciences, University of South Carolina, USA
| | | | - Daniel F Kripke
- Scripps Clinic Viterbi Family Sleep Center, La Jolla, CA, USA
| | - Michael R Irwin
- Cousins Center for Psychoneuorimmunology, Semel Institute for Neuroscience, University of California, Los Angeles, USA
| | | | - Nidha Khan
- Department of Exercise Science, University of South Carolina, USA
| | - Girardin Jean-Louis
- Center for Healthful Behavior Change, Department of Population Health, NYU School of Medicine, USA
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Okamoto Y, Nakagawa S. Effects of daytime light exposure on cognitive brain activity as measured by the ERP P300. Physiol Behav 2015; 138:313-8. [DOI: 10.1016/j.physbeh.2014.10.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 04/29/2014] [Accepted: 10/09/2014] [Indexed: 11/16/2022]
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Ahamed Basha A, Mathangi DC, Shyamala R, Ramesh Rao K. Protective effect of light emitting diode phototherapy on fluorescent light induced retinal damage in Wistar strain albino rats. Ann Anat 2014; 196:312-6. [PMID: 24840621 DOI: 10.1016/j.aanat.2014.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 04/15/2014] [Accepted: 04/16/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND Artificial light at night alters retinal physiology. Several studies have shown that light emitting diode phototherapy protects the retina from the damaging effects of acute light exposure. OBJECTIVE The aim of this study has been to elucidate the protective effects of 670 nm LED light on retinal damage induced by chronic fluorescent light in Wistar rats. METHODS Male Wistar albino rats were divided into four groups: group 1 were control (CL), group 2, 3 and 4 were exposed to fluorescent light (FL), LED preexposure+fluorescent light exposure (LL) and only LED light exposure (OL) respectively. All animals were maintained in their specific exposure regime for 30 days. Fluorescent light of 1800 lx was exposed between 8 pm to 8 am. Rats were exposed to therapeutic LED light of 670 nm of 9 J/cm2 at 25 mW/cm2 for 6 min duration. Histopathological changes in the retina were studied. RESULTS Animals of the FL group showed a significant reduction in the outer nuclear layer thickness and cell count in addition to the total thickness of the retina. LL group which were exposed to 670 nm LED prior to exposure to fluorescent light showed a significant decrease in the degree of damage. CONCLUSIONS 670 nm LED light preexposure is protective to retinal cells against fluorescent light-induced damage.
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Affiliation(s)
- A Ahamed Basha
- Department of Physiology, Chettinad Hospital and Research Institute, Rajiv Gandhi Salai, Kelambakkam, Chennai 603103, India.
| | - D C Mathangi
- Department of Physiology, Chettinad Hospital and Research Institute, Rajiv Gandhi Salai, Kelambakkam, Chennai 603103, India
| | - R Shyamala
- Department of Physiology, Chettinad Hospital and Research Institute, Rajiv Gandhi Salai, Kelambakkam, Chennai 603103, India
| | - K Ramesh Rao
- Department of Pathology, Chettinad Hospital and Research Institute, Rajiv Gandhi Salai, Kelambakkam, Chennai 603103, India
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Okamoto Y, Rea MS, Figueiro MG. Temporal dynamics of EEG activity during short- and long-wavelength light exposures in the early morning. BMC Res Notes 2014; 7:113. [PMID: 24568149 PMCID: PMC3939638 DOI: 10.1186/1756-0500-7-113] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 02/19/2014] [Indexed: 11/25/2022] Open
Abstract
Background It is well known that exposure to light, especially of short wavelength, enhances human alertness during the nighttime. However, more information is needed to elucidate the effects of light wavelength on alertness at other times of day. The present study investigated how two narrowband light spectra affected human alertness during the morning after awakening. We measured electroencephalography (EEG) during 48-minute exposure to narrowband short- and long-wavelength light and darkness in the early morning. Results Power densities of EEG during each light exposure were calculated. The time course of EEG power indicated that, compared with remaining in darkness, the power in the alpha frequency range (8–13 Hz) was significantly lower after approximately 30 minutes of exposures to both the short- and the long-wavelength light. Conclusions These results suggest that not only short-wavelength light but also long-wavelength light, which does not suppress melatonin levels at night, can affect alertness in the early morning. These results suggest that the alerting effects of light in the early morning hours may be mediated by mechanisms other than those that are exclusively sensitive to short-wavelength light.
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Affiliation(s)
- Yosuke Okamoto
- Lighting Research Center, Rensselaer Polytechnic Institute, 21 Union Street, Troy, NY 12180, USA.
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Park SJ. Effects of two types of clothing offering different thermal insulation to the extremities upon nocturnal secretion of urinary 6-sulfatoxymelatonin and sleep propensity. BIOL RHYTHM RES 2013. [DOI: 10.1080/09291016.2013.780699] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Cho JR, Joo EY, Koo DL, Hong SB. Let there be no light: the effect of bedside light on sleep quality and background electroencephalographic rhythms. Sleep Med 2013; 14:1422-5. [DOI: 10.1016/j.sleep.2013.09.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 09/05/2013] [Accepted: 09/16/2013] [Indexed: 11/28/2022]
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Association between pupillary unrest index and waking electroencephalogram activity in sleep-deprived healthy adults. Sleep Med 2013; 14:902-12. [DOI: 10.1016/j.sleep.2013.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 01/30/2013] [Accepted: 02/13/2013] [Indexed: 11/22/2022]
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Okamoto Y, Nakagawa S. Effects of daytime exposures to short- and middle-wavelength lights on cortical activity during a cognitive task. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:1996-1999. [PMID: 24110108 DOI: 10.1109/embc.2013.6609921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This study aimed to assess the effects of light wavelength on human cortical activity during a cognitive task, by observing event-related potentials (ERPs). We measured ERPs when subjects perform an auditory oddball task under daytime exposures to short- and middle-wavelength lights. In the oddball task, a standard tone of 1 kHz and a target tone of 2 kHz were used. Subjects were instructed to press a button as soon as they heard the target tone. The ERP component that occurs approximately 300 ms after a stimulus onset (P300) was analyzed. The results showed that amplitude of P300 in the short-wavelength light condition was significantly larger than that in the middle-wavelength light condition approximately 10-20 min after the start of light exposure. It has been suggested that the amplitude of P300 reflects the amount of attentional resources for a given task. Therefore, the results obtained suggest that amount of attentional resource allocated to the oddball task is increased during exposure to the short-wavelength light in the daytime.
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Forbes-Robertson S, Dudley E, Vadgama P, Cook C, Drawer S, Kilduff L. Circadian disruption and remedial interventions: effects and interventions for jet lag for athletic peak performance. Sports Med 2012; 42:185-208. [PMID: 22299812 DOI: 10.2165/11596850-000000000-00000] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Jet lag has potentially serious deleterious effects on performance in athletes following transmeridian travel, where time zones are crossed eastwards or westwards; as such, travel causes specific effects related to desynchronization of the athlete's internal body clock or circadian clock. Athletes are particularly sensitive to the effects of jet lag, as many intrinsic aspects of sporting performance show a circadian rhythm, and optimum competitive results require all aspects of the athlete's mind and body to be working in tandem at their peak efficiency. International competition often requires transmeridian travel, and competition timings cannot be adjusted to suit individual athletes. It is therefore in the interest of the individual athlete and team to understand the effects of jet lag and the potential adaptation strategies that can be adopted. In this review, we describe the underlying genetic and physiological mechanisms controlling the circadian clock and its inherent ability to adapt to external conditions on a daily basis. We then examine the fundamentals of the various adaptation stimuli, such as light, chronobiotics (e.g. melatonin), exercise, and diet and meal timing, with particular emphasis on their suitability as strategies for competing athletes on the international circuit. These stimuli can be artificially manipulated to produce phase shifts in the circadian rhythm to promote adaptation in the optimum direction, but care must be taken to apply them at the correct time and dose, as the effects produced on the circadian rhythm follow a phase-response curve, with pronounced shifts in direction at different times. Light is the strongest realigning stimulus and careful timing of light exposure and avoidance can promote adjustment. Chronobiotics such as melatonin can also be used to realign the circadian clock but, as well as timing and dosage issues, there are also concerns as to its legal status in different countries and with the World Anti-Doping Agency. Experimental data concerning the effects of food intake and exercise timing on jet lag is limited to date in humans, and more research is required before firm guidelines can be stated. All these stimuli can also be used in pre-flight adaptation strategies to promote adjustment in the required direction, and implementation of these is described. In addition, the effects of individual variability at the behavioural and genetic levels are also discussed, along with the current limitations in assessment of these factors, and we then put forward three case studies, as examples of practical applications of these strategies, focusing on adaptations to travel involving competition in the Rugby Sevens World Cup and the 2016 Summer Olympics in Rio de Janeiro, Brazil. Finally, we provide a list of practice points for optimal adaptation of athletes to jet lag.
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Affiliation(s)
- Sarah Forbes-Robertson
- Sport and Exercise Science Portfolio, School of Engineering, Swansea University, Swansea, UK.
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Staikou C, Kyrozis A, Moschovos C, Fassoulaki A. Effects of morning melatonin administration on electroencephalographic theta to alpha power ratio in reproductive versus postmenopausal healthy female volunteers. Neurosci Lett 2011; 507:90-3. [PMID: 22172935 DOI: 10.1016/j.neulet.2011.11.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 11/23/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
Abstract
OBJECTIVE The aim of the present study was to investigate the effect of exogenous morning melatonin administration on the electroencephalogram of reproductive versus postmenopausal women. METHODS Twenty-six female, reproductive and postmenopausal healthy volunteers were randomly assigned to receive melatonin or placebo at 9:00 in the morning. Twelve electroencephalographic recording sessions were performed before the intake of melatonin or placebo and at 15, 30, 45, 60, 75, 90, 120, 150, 180, 240, and 300 min. Theta to alpha ratios for every subject, channel and session were mathematically processed to yield the logarithm (base 10) of the spectral (theta power)/(alpha power) ratio for the 12 electroencephalographic sessions, weighted to the baseline ratio (LwRs). The LwRs were compared between melatonin groups (reproductive versus postmenopausal women) and also between melatonin and control groups. RESULTS Data from 24 women were analyzed. The LwRs in the reproductive women were significantly lower than the LwRs in postmenopausal women at 60, 180, 240 and 300 min after melatonin consumption (p=0.007, 0.041, 0.008 and 0.040 respectively). In reproductive women, the LwRs of subjects who received melatonin were significantly lower compared to their controls at 60, 240 and 300 min after melatonin or placebo intake (p=0.005, 0.006 and 0.019 respectively). In postmenopausal women, no significant differences in the LwRs were calculated for any time point between melatonin and control groups. CONCLUSIONS Our results show that morning melatonin administration produces no electroencephalographic changes in postmenopausal women. In contrast, electroencephalographic changes suggesting a possible awaking effect were observed in reproductive women.
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Affiliation(s)
- Chryssoula Staikou
- 1st Department of Anesthesiology, Aretaieio Hospital, Medical School, University of Athens, 76 Vassilissis Sofias Ave., 11528 Athens, Greece
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Münch M, Scheuermaier KD, Zhang R, Dunne SP, Guzik AM, Silva EJ, Ronda JM, Duffy JF. Effects on subjective and objective alertness and sleep in response to evening light exposure in older subjects. Behav Brain Res 2011; 224:272-8. [PMID: 21664380 PMCID: PMC3169848 DOI: 10.1016/j.bbr.2011.05.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 05/25/2011] [Indexed: 10/18/2022]
Abstract
Evening bright light exposure is reported to ameliorate daytime sleepiness and age-related sleep complaints, and also delays the timing of circadian rhythms. We tested whether evening light exposure given to older adults with sleep-wake complaints would delay the timing of their circadian rhythms with respect to their sleep timing, thereby reducing evening sleepiness and improving subsequent sleep quality. We examined the impact of evening light exposure from two different light sources on subjective alertness, EEG activity during wakefulness, and sleep stages. Ten healthy older adults with sleep complaints (mean age=63.3 years; 6F) participated in a 13-day study. After three baseline days, circadian phase was assessed. On the evening of days 5-8 the subjects were exposed for 2h to either polychromatic blue-enriched white light or standard white fluorescent light, and on the following day circadian phase was re-assessed. Subjects were allowed to leave the laboratory during all but the two days when the circadian phase assessment took place. Evening assessments of subjective alertness, and wake and sleep EEG data were analyzed. Subjective alertness and wake EEG activity in the alpha range (9.75-11.25 Hz) were significantly higher during light exposures when compared to the pre-light exposure evening (p<0.05). The light exposures produced circadian phase shifts and significantly prolonged latency to rapid eye-movement (REM) sleep for both light groups (p<0.05). The increase in wake EEG alpha activity during the light exposures was negatively correlated with REM sleep duration (p<0.05). Evening light exposure could benefit older adults with early evening sleepiness, without negatively impacting the subsequent sleep episode.
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Affiliation(s)
- M Münch
- Division of Sleep Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - KD Scheuermaier
- Division of Sleep Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - R Zhang
- Division of Sleep Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA
| | - SP Dunne
- Division of Sleep Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA
| | - AM Guzik
- Division of Sleep Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA
| | - EJ Silva
- Division of Sleep Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA
| | - JM Ronda
- Division of Sleep Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - JF Duffy
- Division of Sleep Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
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Brown MJ, Jacobs DE. Residential light and risk for depression and falls: results from the LARES study of eight European cities. Public Health Rep 2011; 126 Suppl 1:131-40. [PMID: 21563721 PMCID: PMC3072912 DOI: 10.1177/00333549111260s117] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES We examined the relationship between self-reported inadequate residential natural light and risk for depression or falls among adults aged 18 years or older. METHODS Generalized estimating equations were used to calculate the odds of depression or falls in participants with self-reported inadequate natural residential light vs. those reporting adequate light (n = 6,017) using data from the World Health Organization's Large Analysis and Review of European Housing and Health Survey, a large cross-sectional study of housing and health in representative populations from eight European cities. RESULTS Participants reporting inadequate natural light in their dwellings were 1.4 times (95% confidence interval [CI] 1.2,1.7) as likely to report depression and 1.5 times (95% CI 1.2, 1.9) as likely to report a fall compared with those satisfied with their dwelling's light. After adjustment for major confounders, the likelihood of depression changed slightly, while the likelihood of a fall increased to 2.5 (95% CI 1.5, 4.2). CONCLUSION Self-reported inadequate light in housing is independently associated with depression and falls. Increasing light in housing, a relatively inexpensive intervention, may improve two distinct health conditions.
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Affiliation(s)
- Mary Jean Brown
- Centers for Disease Control and Prevention, National Center for Environmental Health, Division of Emergency and Environmental Health Services, Atlanta, GA 30341, USA.
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The effect of narrowband 500nm light on daytime sleep in humans. Physiol Behav 2011; 103:197-202. [DOI: 10.1016/j.physbeh.2011.01.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 01/05/2011] [Accepted: 01/24/2011] [Indexed: 11/19/2022]
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Non-visual effects of light on melatonin, alertness and cognitive performance: can blue-enriched light keep us alert? PLoS One 2011; 6:e16429. [PMID: 21298068 PMCID: PMC3027693 DOI: 10.1371/journal.pone.0016429] [Citation(s) in RCA: 221] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 12/16/2010] [Indexed: 11/19/2022] Open
Abstract
Background Light exposure can cascade numerous effects on the human circadian process via the non-imaging forming system, whose spectral relevance is highest in the short-wavelength range. Here we investigated if commercially available compact fluorescent lamps with different colour temperatures can impact on alertness and cognitive performance. Methods Sixteen healthy young men were studied in a balanced cross-over design with light exposure of 3 different light settings (compact fluorescent lamps with light of 40 lux at 6500K and at 2500K and incandescent lamps of 40 lux at 3000K) during 2 h in the evening. Results Exposure to light at 6500K induced greater melatonin suppression, together with enhanced subjective alertness, well-being and visual comfort. With respect to cognitive performance, light at 6500K led to significantly faster reaction times in tasks associated with sustained attention (Psychomotor Vigilance and GO/NOGO Task), but not in tasks associated with executive function (Paced Visual Serial Addition Task). This cognitive improvement was strongly related with attenuated salivary melatonin levels, particularly for the light condition at 6500K. Conclusions Our findings suggest that the sensitivity of the human alerting and cognitive response to polychromatic light at levels as low as 40 lux, is blue-shifted relative to the three-cone visual photopic system. Thus, the selection of commercially available compact fluorescent lights with different colour temperatures significantly impacts on circadian physiology and cognitive performance at home and in the workplace.
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Chellappa SL, Gordijn MC, Cajochen C. Can light make us bright? Effects of light on cognition and sleep. PROGRESS IN BRAIN RESEARCH 2011; 190:119-33. [DOI: 10.1016/b978-0-444-53817-8.00007-4] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Thorne HC, Jones KH, Peters SP, Archer SN, Dijk DJ. Daily and Seasonal Variation in the Spectral Composition of Light Exposure in Humans. Chronobiol Int 2010; 26:854-66. [DOI: 10.1080/07420520903044315] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Phipps-Nelson J, Redman JR, Schlangen LJM, Rajaratnam SMW. BLUE LIGHT Exposure Reduces Objective Measures of Sleepiness during Prolonged Nighttime Performance Testing. Chronobiol Int 2010; 26:891-912. [DOI: 10.1080/07420520903044364] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Cajochen C, Chellappa S, Schmidt C. What keeps us awake? The role of clocks and hourglasses, light, and melatonin. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2010; 93:57-90. [PMID: 20970001 DOI: 10.1016/s0074-7742(10)93003-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
What is it that keeps us awake? Our assumption is that we consciously control our daily activities including sleep-wake behavior, as indicated by our need to make use of an alarm clock to wake up in the morning in order to be at work on time. However, when we travel across multiple time zones or do shift work, we realize that our intentionally planned timings to rest and to remain active can interfere with an intrinsic regulation of sleep/wake cycles. This regulation is driven by a small region in the anterior hypothalamus of the brain, termed as the "circadian clock". This clock spontaneously synchronizes with the environmental light-dark cycle, thus enabling all organisms to adapt to and anticipate environmental changes. As a result, the circadian clock actively gates sleep and wakefulness to occur in synchrony with the light-dark cycles. Indeed, our internal clock is our best morning alarm clock, since it shuts off melatonin production and boosts cortisol secretion and heart rate 2-3h prior awakening from Morpheus arms. The main reason most of us still use artificial alarm clocks is that we habitually carry on a sleep depth and/or the sleep-wake timing is not ideally matched with our social/work schedule. This in turn can lead hourglass processes, as indexed by accumulated homeostatic sleep need over time, to strongly oppose the clock. To add to the complexity of our sleep and wakefulness behavior, light levels as well as exogenous melatonin can impinge on the clock, by means of their so-called zeitgeber (synchronizer) role or by acutely promoting sleep or wakefulness. Here we attempt to bring a holistic view on how light, melatonin, and the brain circuitry underlying circadian and homeostatic processes can modulate sleep and in particular alertness, by actively promoting awakening/arousal and sleep at certain times during the 24-h day.
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Affiliation(s)
- Christian Cajochen
- Center for Chronobiology, Psychiatric Hospital of the University of Basel, CH-4012 Basel, Switzerland
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Vosko AM, Colwell CS, Avidan AY. Jet lag syndrome: circadian organization, pathophysiology, and management strategies. Nat Sci Sleep 2010; 2:187-98. [PMID: 23616709 PMCID: PMC3630947 DOI: 10.2147/nss.s6683] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The circadian system regulates the cyclical occurrence of wakefulness and sleep through a series of oscillatory networks that comprise two different theoretical processes. The suprachiasmatic nucleus (SCN) of the hypothalamus contains the master oscillatory network necessary for coordinating these daily rhythms, and in addition to its ability to robustly generate rhythms, it can also synchronize to environmental light cues. During jet lag, abrupt shifts in the environmental light-dark cycle temporarily desynchronize the SCN and downstream oscillatory networks from each other, resulting in increased sleepiness and impaired daytime functioning. Polysomnographic data show that not only does jet lag result in changes of sleep-wake timing, but also in different aspects of sleep architecture. This type of circadian misalignment can further lead to a cluster of symptoms including major metabolic, cardiovascular, psychiatric, and neurological impairments. There are a number of treatment options for jet lag involving bright light exposure, melatonin, and use of hypnotics, but their efficacy greatly depends on their time of use, the length of time in the new time zone, and the specific circadian disturbance involved. The aim of this review is to provide mechanistic links between the fields of sleep and circadian rhythms to understand the biological basis of jet lag and to apply this information to clinical management strategies.
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Affiliation(s)
- Andrew M Vosko
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA
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