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Martin CV, Joyce-McCoach J, Peddle M, East CE. Sleep deprivation and medication administration errors in registered nurses-A scoping review. J Clin Nurs 2024; 33:859-873. [PMID: 37872866 DOI: 10.1111/jocn.16912] [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: 06/02/2023] [Revised: 08/31/2023] [Accepted: 10/02/2023] [Indexed: 10/25/2023]
Abstract
AIM To explore whether sleep deprivation contributes to medication errors in registered nurses (RNs). BACKGROUND Sleep deprivation is a potential issue for RNs, particularly those who work shifts. Sleep deprivation has been found to have a negative impact on numerous cognitive processes. Nurses administer several medications to patients a day, potentially while sleep deprived-anecdotal reports suggest that this could result in an increased risk of error occurring. DESIGN A scoping review was conducted using the Prisma-ScR extension framework to explore what is known about the effect of RNs' sleep deprivation on medication administration errors. METHODS A search of databases generated 171 results. When inclusion and exclusion criteria were applied, 18 empirical studies were analysed. Studies included retrospective analysis of errors, surveys of perceptions of causes and observational studies. RESULTS Data indicated that RNs consider fatigue, which may be caused by sleep deprivation, to be a contributing factor to medication errors. The search only identified three observer studies, which provided conflicting results as to whether lack of sleep contributes to the error rate. Of the numerous tools used to measure sleep, the Pittsburgh Sleep Quality Index was the most frequently used. CONCLUSION Although RNs anecdotally consider a lack of sleep potentially contributes to medication errors, there is insufficient research to provide robust evidence to confirm this assumption. NO PATIENT OR PUBLIC CONTRIBUTIONS Patient or public contributions were not required for this scoping review. RELEVANCE TO CLINICAL PRACTICE Sleep deprivation is a potential issue for nurses, especially those who work shifts. Poor sleep impacts cognitive processes that potentially could increase errors. Nurses should be aware of the impact sleep may have on patient safety.
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Affiliation(s)
- Christopher Vincent Martin
- School of Nursing and Midwifery, La Trobe University, Bundoora, Victoria, Australia
- School of Nursing, Midwifery and Paramedicine, Australian Catholic University, Ballarat, Victoria, Australia
| | - Joanne Joyce-McCoach
- School of Nursing and Midwifery, La Trobe University, Bundoora, Victoria, Australia
| | - Monica Peddle
- School of Nursing and Midwifery, Deakin University, Burwood, Victoria, Australia
| | - Christine Elizabeth East
- Judith Lumley Centre, School of Nursing and Midwifery, La Trobe University, Bundoora, Victoria, Australia
- Mercy Health, Melbourne, Victoria, Australia
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Song YM, Choi SJ, Park SH, Lee SJ, Joo EY, Kim JK. A real-time, personalized sleep intervention using mathematical modeling and wearable devices. Sleep 2023; 46:zsad179. [PMID: 37422720 DOI: 10.1093/sleep/zsad179] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/03/2023] [Indexed: 07/10/2023] Open
Abstract
The prevalence of artificial light exposure has enabled us to be active any time of the day or night, leading to the need for high alertness outside of traditional daytime hours. To address this need, we developed a personalized sleep intervention framework that analyzes real-world sleep-wake patterns obtained from wearable devices to maximize alertness during specific target periods. Our framework utilizes a mathematical model that tracks the dynamic sleep pressure and circadian rhythm based on the user's sleep history. In this way, the model accurately predicts real-time alertness, even for shift workers with complex sleep and work schedules (N = 71, t = 13~21 days). This allowed us to discover a new sleep-wake pattern called the adaptive circadian split sleep, which incorporates a main sleep period and a late nap to enable high alertness during both work and non-work periods of shift workers. We further developed a mobile application that integrates this framework to recommend practical, personalized sleep schedules for individual users to maximize their alertness during a targeted activity time based on their desired sleep onset and available sleep duration. This can reduce the risk of errors for those who require high alertness during nontraditional activity times and improve the health and quality of life for those leading shift work-like lifestyles.
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Affiliation(s)
- Yun Min Song
- Department of Mathematical Sciences, KAIST, Daejeon, Republic of Korea
- Biomedical Mathematics Group, Institute for Basic Science, Daejeon, Republic of Korea
| | - Su Jung Choi
- Graduate School of Clinical Nursing Science, Sungkyunkwan University, Seoul, Republic of Korea
| | - Se Ho Park
- Biomedical Mathematics Group, Institute for Basic Science, Daejeon, Republic of Korea
- Department of Mathematics, University of Wisconsin-Madison, Madison, WI, USA
| | - Soo Jin Lee
- Department of Neurology, Neuroscience Center, Samsung Medical Center, Samsung Biomedical Research Institute, School of Medicine, Sungkyunkwan University, Seoul, Republic of Korea
| | - Eun Yeon Joo
- Department of Neurology, Neuroscience Center, Samsung Medical Center, Samsung Biomedical Research Institute, School of Medicine, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jae Kyoung Kim
- Department of Mathematical Sciences, KAIST, Daejeon, Republic of Korea
- Biomedical Mathematics Group, Institute for Basic Science, Daejeon, Republic of Korea
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Van Dongen HPA, Basner M, Mullington JM, Carlin M. Foreword: Festschrift in honor of David Dinges, scientist and mentor extraordinaire. SLEEP ADVANCES : A JOURNAL OF THE SLEEP RESEARCH SOCIETY 2023; 4:zpad020. [PMID: 38020731 PMCID: PMC10658658 DOI: 10.1093/sleepadvances/zpad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Affiliation(s)
- Hans P A Van Dongen
- Sleep and Performance Research Center and Department of Translational Medicine and Physiology, Washington State University Health Sciences, Spokane, WA, USA
| | - Mathias Basner
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, , USA
| | - Janet M Mullington
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Michele Carlin
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, , USA
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Gurubhagavatula I, Barger LK, Barnes CM, Basner M, Boivin DB, Dawson D, Drake CL, Flynn-Evans EE, Mysliwiec V, Patterson PD, Reid KJ, Samuels C, Shattuck NL, Kazmi U, Carandang G, Heald JL, Van Dongen HP. Guiding principles for determining work shift duration and addressing the effects of work shift duration on performance, safety, and health: guidance from the American Academy of Sleep Medicine and the Sleep Research Society. J Clin Sleep Med 2021; 17:2283-2306. [PMID: 34666885 PMCID: PMC8636361 DOI: 10.5664/jcsm.9512] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 11/13/2022]
Abstract
CITATION Risks associated with fatigue that accumulates during work shifts have historically been managed through working time arrangements that specify fixed maximum durations of work shifts and minimum durations of time off. By themselves, such arrangements are not sufficient to curb risks to performance, safety, and health caused by misalignment between work schedules and the biological regulation of waking alertness and sleep. Science-based approaches for determining shift duration and mitigating associated risks, while addressing operational needs, require: (1) a recognition of the factors contributing to fatigue and fatigue-related risks; (2) an understanding of evidence-based countermeasures that may reduce fatigue and/or fatigue-related risks; and (3) an informed approach to selecting workplace-specific strategies for managing work hours. We propose a series of guiding principles to assist stakeholders with designing a shift duration decision-making process that effectively balances the need to meet operational demands with the need to manage fatigue-related risks.
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Affiliation(s)
- Indira Gurubhagavatula
- Division of Sleep Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Laura K. Barger
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women’s Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Christopher M. Barnes
- Department of Management and Organization, Foster School of Business, University of Washington, Seattle, WA, USA
| | - Mathias Basner
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Diane B. Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Drew Dawson
- Appleton Institute, Central Queensland University, Wayville, SA, Australia
| | | | - Erin E. Flynn-Evans
- Fatigue Countermeasures Laboratory, NASA Ames Research Center, Moffett Field, CA, USA
| | - Vincent Mysliwiec
- STRONG STAR ORU, Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center, San Antonio, TX, USA
| | - P. Daniel Patterson
- Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kathryn J. Reid
- Center for Circadian and Sleep Medicine, Department of Neurology, Division of Sleep Medicine, Northwestern University, Chicago, IL, USA
| | - Charles Samuels
- Centre for Sleep and Human Performance, Calgary, Alberta, Canada
| | - Nita Lewis Shattuck
- Operations Research Department, Naval Postgraduate School, Monterey, CA, USA
| | - Uzma Kazmi
- American Academy of Sleep Medicine, Darien, IL, USA
| | | | | | - Hans P.A. Van Dongen
- Sleep and Performance Research Center, Washington State University, Spokane, WA, USA
- Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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5
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Bessone P, Rao G, Schilbach F, Schofield H, Toma M. The Economic Consequences of Increasing Sleep Among the Urban Poor. THE QUARTERLY JOURNAL OF ECONOMICS 2021; 136:1887-1941. [PMID: 34220361 DOI: 10.7910/dvn/gj9qpc] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The urban poor in developing countries face challenging living environments, which may interfere with good sleep. Using actigraphy to measure sleep objectively, we find that low-income adults in Chennai, India, sleep only 5.5 hours a night on average despite spending 8 hours in bed. Their sleep is highly interrupted, with sleep efficiency-sleep per time in bed-comparable to those with disorders such as sleep apnea or insomnia. A randomized three-week treatment providing information, encouragement, and improvements to home sleep environments increased sleep duration by 27 minutes a night by inducing more time in bed. Contrary to expert predictions and a large body of sleep research, increased nighttime sleep had no detectable effects on cognition, productivity, decision making, or well being, and led to small decreases in labor supply. In contrast, short afternoon naps at the workplace improved an overall index of outcomes by 0.12 standard deviations, with significant increases in productivity, psychological well-being, and cognition, but a decrease in work time.
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Affiliation(s)
| | - Gautam Rao
- Harvard University and National Bureau of Economic Research, United States
| | - Frank Schilbach
- Massaschusetts Institute of Technology and National Bureau of Economic Research, United States
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6
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Bessone P, Rao G, Schilbach F, Schofield H, Toma M. The Economic Consequences of Increasing Sleep Among the Urban Poor. THE QUARTERLY JOURNAL OF ECONOMICS 2021; 136:1887-1941. [PMID: 34220361 PMCID: PMC8242594 DOI: 10.1093/qje/qjab013] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The urban poor in developing countries face challenging living environments, which may interfere with good sleep. Using actigraphy to measure sleep objectively, we find that low-income adults in Chennai, India, sleep only 5.5 hours a night on average despite spending 8 hours in bed. Their sleep is highly interrupted, with sleep efficiency-sleep per time in bed-comparable to those with disorders such as sleep apnea or insomnia. A randomized three-week treatment providing information, encouragement, and improvements to home sleep environments increased sleep duration by 27 minutes a night by inducing more time in bed. Contrary to expert predictions and a large body of sleep research, increased nighttime sleep had no detectable effects on cognition, productivity, decision making, or well being, and led to small decreases in labor supply. In contrast, short afternoon naps at the workplace improved an overall index of outcomes by 0.12 standard deviations, with significant increases in productivity, psychological well-being, and cognition, but a decrease in work time.
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Affiliation(s)
| | - Gautam Rao
- Harvard University and National Bureau of Economic Research, United States
| | - Frank Schilbach
- Massaschusetts Institute of Technology and National Bureau of Economic Research, United States
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7
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Gurubhagavatula I, Barger LK, Barnes CM, Basner M, Boivin DB, Dawson D, Drake CL, Flynn-Evans EE, Mysliwiec V, Patterson PD, Reid KJ, Samuels C, Shattuck NL, Kazmi U, Carandang G, Heald JL, Van Dongen HPA. Guiding principles for determining work shift duration and addressing the effects of work shift duration on performance, safety, and health: guidance from the American Academy of Sleep Medicine and the Sleep Research Society. Sleep 2021; 44:6312566. [PMID: 34373924 DOI: 10.1093/sleep/zsab161] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/17/2021] [Indexed: 11/12/2022] Open
Abstract
Risks associated with fatigue that accumulates during work shifts have historically been managed through working time arrangements that specify fixed maximum durations of work shifts and minimum durations of time off. By themselves, such arrangements are not sufficient to curb risks to performance, safety, and health caused by misalignment between work schedules and the biological regulation of waking alertness and sleep. Science-based approaches for determining shift duration and mitigating associated risks, while addressing operational needs, require: (1) a recognition of the factors contributing to fatigue and fatigue-related risks; (2) an understanding of evidence-based countermeasures that may reduce fatigue and/or fatigue-related risks; and (3) an informed approach to selecting workplace-specific strategies for managing work hours. We propose a series of guiding principles to assist stakeholders with designing a shift duration decision-making process that effectively balances the need to meet operational demands with the need to manage fatigue-related risks.
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Affiliation(s)
- Indira Gurubhagavatula
- Division of Sleep Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Corporal Michael Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Laura K Barger
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, USA.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Christopher M Barnes
- Department of Management and Organization, Foster School of Business, University of Washington, Seattle, WA, USA
| | - Mathias Basner
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Diane B Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Drew Dawson
- Appleton Institute, Central Queensland University, Wayville, SA, Australia
| | | | - Erin E Flynn-Evans
- Fatigue Countermeasures Laboratory, NASA Ames Research Center, Moffett Field, CA, USA
| | - Vincent Mysliwiec
- STRONG STAR ORU, Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center, San Antonio, TX, USA
| | - P Daniel Patterson
- Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kathryn J Reid
- Center for Circadian and Sleep Medicine, Department of Neurology, Division of Sleep Medicine, Northwestern University, Chicago, IL, USA
| | - Charles Samuels
- Centre for Sleep and Human Performance, Calgary, Alberta, Canada
| | - Nita Lewis Shattuck
- Operations Research Department, Naval Postgraduate School, Monterey, CA, USA
| | - Uzma Kazmi
- American Academy of Sleep Medicine, Darien, IL, USA
| | | | | | - Hans P A Van Dongen
- Sleep and Performance Research Center, Washington State University, Spokane, WA, USA.,Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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8
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BaHammam AS, Alghannam AF, Aljaloud KS, Aljuraiban GS, AlMarzooqi MA, Dobia AM, Alothman SA, Aljuhani O, Alfawaz RA. Joint consensus statement of the Saudi Public Health Authority on the recommended amount of physical activity, sedentary behavior, and sleep duration for healthy Saudis: Background, methodology, and discussion. Ann Thorac Med 2021; 16:225-238. [PMID: 34484437 PMCID: PMC8388569 DOI: 10.4103/atm.atm_32_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/19/2021] [Indexed: 02/06/2023] Open
Abstract
The Saudi Public Health Authority recently prepared a Consensus Statement regarding how much time a person should spend engaged in physical activity, sedentary behavior, and sleep to promote optimal health across all age groups. This paper describes the background literature, methodology, and modified RAND Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation (GRADE)-ADOLOPMENT approach that guided the development process. A Leadership Group and Consensus Panels were formed, and credible existing guidelines were identified. The Panel identified clear criteria to choose the best practice guidelines for the set objectives after evaluation, based on GRADE table evidence, findings table summaries, and draft recommendations. Updating of the selected practice guidelines was performed, and the Consensus Panels separately reviewed the evidence for each behavior and decided to adopt or adapt the selected practice guideline recommendations or create de novo recommendations. Data related to cultural factors that may affect the studied behaviors, such as prayer times, midday napping or "Qailulah," and the holy month of Ramadan, were also reviewed. Two rounds of voting were conducted to reach a consensus for each behavior.
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Affiliation(s)
- Ahmed S. BaHammam
- The University Sleep Disorders Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- National Plan for Science and Technology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah F. Alghannam
- Lifestyle and Health Research Center, Health Sciences Research Center, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Khalid Saad Aljaloud
- Department of Exercise Physiology, College of Sport Sciences and Physical Activity, King Saud University, Riyadh, Saudi Arabia
| | - Ghadeer S. Aljuraiban
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Mezna A. AlMarzooqi
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Ali M. Dobia
- Comprehensive Specialized Clinics for the Security Forces in Jazan, General Administration for Medical Services, Ministry of Interior, Riyadh, Saudi Arabia
| | - Shaima A. Alothman
- Lifestyle and Health Research Center, Health Sciences Research Center, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Osama Aljuhani
- Department of Physical Education, College of Sport Sciences and Physical Activity, King Saud University, Riyadh, Saudi Arabia
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Weaver MD, Sletten TL, Foster RG, Gozal D, Klerman EB, Rajaratnam SMW, Roenneberg T, Takahashi JS, Turek FW, Vitiello MV, Young MW, Czeisler CA. Adverse impact of polyphasic sleep patterns in humans: Report of the National Sleep Foundation sleep timing and variability consensus panel. Sleep Health 2021; 7:293-302. [PMID: 33795195 DOI: 10.1016/j.sleh.2021.02.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 01/02/2023]
Abstract
Polyphasic sleep is the practice of distributing multiple short sleep episodes across the 24-hour day rather than having one major and possibly a minor ("nap") sleep episode each day. While the prevalence of polyphasic sleep is unknown, anecdotal reports suggest attempts to follow this practice are common, particularly among young adults. Polyphasic-sleep advocates claim to thrive on as little as 2 hours of total sleep per day. However, significant concerns have been raised that polyphasic sleep schedules can result in health and safety consequences. We reviewed the literature to identify the impact of polyphasic sleep schedules (excluding nap or siesta schedules) on health, safety, and performance outcomes. Of 40,672 potentially relevant publications, with 2,023 selected for full-text review, 22 relevant papers were retained. We found no evidence supporting benefits from following polyphasic sleep schedules. Based on the current evidence, the consensus opinion is that polyphasic sleep schedules, and the sleep deficiency inherent in those schedules, are associated with a variety of adverse physical health, mental health, and performance outcomes. Striving to adopt a schedule that significantly reduces the amount of sleep per 24 hours and/or fragments sleep into multiple episodes throughout the 24-hour day is not recommended.
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Affiliation(s)
- Matthew D Weaver
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Tracey L Sletten
- Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Clayton, Australia
| | - Russell G Foster
- Sleep & Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - David Gozal
- Department of Child Health, University of Missouri, Columbia, Missouri, USA
| | - Elizabeth B Klerman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA; Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Shantha M W Rajaratnam
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA; Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Clayton, Australia
| | - Till Roenneberg
- Institute for Medical Psychology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Joseph S Takahashi
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, Texas, USA; Howard Hughes Medical Institute, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Fred W Turek
- Center for Sleep and Circadian Biology, Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Michael V Vitiello
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, USA
| | - Michael W Young
- Laboratory of Genetics, The Rockefeller University, New York, New York, USA
| | - Charles A Czeisler
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, USA.
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McCauley ME, McCauley P, Riedy SM, Banks S, Ecker AJ, Kalachev LV, Rangan S, Dinges DF, Van Dongen HPA. Fatigue risk management based on self-reported fatigue: Expanding a biomathematical model of fatigue-related performance deficits to also predict subjective sleepiness. TRANSPORTATION RESEARCH. PART F, TRAFFIC PSYCHOLOGY AND BEHAVIOUR 2021; 79:94-106. [PMID: 33994837 PMCID: PMC8117424 DOI: 10.1016/j.trf.2021.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Biomathematical models of fatigue can be used to predict neurobehavioral deficits during sleep/wake or work/rest schedules. Current models make predictions for objective performance deficits and/or subjective sleepiness, but known differences in the temporal dynamics of objective versus subjective outcomes have not been addressed. We expanded a biomathematical model of fatigue previously developed to predict objective performance deficits as measured on the Psychomotor Vigilance Test (PVT) to also predict subjective sleepiness as self-reported on the Karolinska Sleepiness Scale (KSS). Four model parameters were re-estimated to capture the distinct dynamics of the KSS and account for the scale difference between KSS and PVT. Two separate ensembles of datasets - drawn from laboratory studies of sleep deprivation, sleep restriction, simulated night work, napping, and recovery sleep - were used for calibration and subsequent validation of the model for subjective sleepiness. The expanded model was found to exhibit high prediction accuracy for subjective sleepiness, while retaining high prediction accuracy for objective performance deficits. Application of the validated model to an example scenario based on cargo aviation operations revealed divergence between predictions for objective and subjective outcomes, with subjective sleepiness substantially underestimating accumulating objective impairment, which has important real-world implications. In safety-sensitive operations such as commercial aviation, where self-ratings of sleepiness are used as part of fatigue risk management, the systematic differences in the temporal dynamics of objective versus subjective measures of functional impairment point to a potentially significant risk evaluation sensitivity gap. The expanded biomathematical model of fatigue presented here provides a useful quantitative tool to bridge this previously unrecognized gap.
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Affiliation(s)
- Mark E. McCauley
- Sleep and Performance Research Center, Washington State University Health Sciences Spokane
- Elson S. Floyd College of Medicine, Washington State University Health Sciences Spokane
| | - Peter McCauley
- Sleep and Performance Research Center, Washington State University Health Sciences Spokane
| | - Samantha M. Riedy
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, University of Pennsylvania Perelman School of Medicine
| | - Siobhan Banks
- Behaviour-Brain-Body Research Centre, University of South Australia
| | - Adrian J. Ecker
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, University of Pennsylvania Perelman School of Medicine
| | | | | | - David F. Dinges
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, University of Pennsylvania Perelman School of Medicine
| | - Hans P. A. Van Dongen
- Sleep and Performance Research Center, Washington State University Health Sciences Spokane
- Elson S. Floyd College of Medicine, Washington State University Health Sciences Spokane
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11
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Basner M, Moore TM, Nasrini J, Gur RC, Dinges DF. Response speed measurements on the psychomotor vigilance test: how precise is precise enough? Sleep 2021; 44:5859160. [PMID: 32556295 DOI: 10.1093/sleep/zsaa121] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/18/2020] [Indexed: 01/27/2023] Open
Abstract
STUDY OBJECTIVES The psychomotor vigilance test (PVT) is frequently used to measure behavioral alertness in sleep research on various software and hardware platforms. In contrast to many other cognitive tests, PVT response time (RT) shifts of a few milliseconds can be meaningful. It is, therefore, important to use calibrated systems, but calibration standards are currently missing. This study investigated the influence of system latency bias and its variability on two frequently used PVT performance metrics, attentional lapses (RTs ≥500 ms) and response speed, in sleep-deprived and alert participants. METHODS PVT data from one acute total (N = 31 participants) and one chronic partial (N = 43 participants) sleep deprivation protocol were the basis for simulations in which response bias (±15 ms) and its variability (0-50 ms) were systematically varied and transgressions of predefined thresholds (i.e. ±1 for lapses, ±0.1/s for response speed) recorded. RESULTS Both increasing bias and its variability caused deviations from true scores that were higher for the number of lapses in sleep-deprived participants and for response speed in alert participants. Threshold transgressions were typically rare (i.e. <5%) if system latency bias was less than ±5 ms and its standard deviation was ≤10 ms. CONCLUSIONS A bias of ±5 ms with a standard deviation of ≤10 ms could be considered maximally allowable margins for calibrating PVT systems for timing accuracy. Future studies should report the average system latency and its standard deviation in addition to adhering to published standards for administering and analyzing the PVT.
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Affiliation(s)
- Mathias Basner
- Unit of Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Tyler M Moore
- Brain Behavior Laboratory, Neuropsychiatry Section, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Jad Nasrini
- Unit of Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ruben C Gur
- Brain Behavior Laboratory, Neuropsychiatry Section, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - David F Dinges
- Unit of Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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Lo JC, Leong RLF, Ng ASC, Jamaluddin SA, Ong JL, Ghorbani S, Lau T, Chee NIYN, Gooley JJ, Chee MWL. Cognitive effects of split and continuous sleep schedules in adolescents differ according to total sleep opportunity. Sleep 2021; 43:5867089. [PMID: 32619240 PMCID: PMC8061132 DOI: 10.1093/sleep/zsaa129] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/27/2020] [Indexed: 02/07/2023] Open
Abstract
STUDY OBJECTIVES We compared the basic cognitive functions of adolescents undergoing split (nocturnal sleep + daytime nap) and continuous nocturnal sleep schedules when total sleep opportunity was either below or within the recommended range (i.e. 6.5 or 8 h). METHODS Adolescent participants (age: 15-19 year) in the 8-h split (n = 24) and continuous (n = 29) sleep groups were compared with 6.5-h split and continuous sleep groups from a previous study (n = 58). These protocols involved two baseline nights (9-h time-in-bed [TIB]), 5 nights of sleep manipulation, 2 recovery nights (9-h TIB), followed by a second cycle of sleep manipulation (3 nights) and recovery (2 nights). Cognitive performance, subjective sleepiness, and mood were evaluated daily; sleep was assessed using polysomnography. RESULTS Splitting 6.5 h of sleep with a mid-afternoon nap offered a boost to cognitive function compared to continuous nocturnal sleep. However, when total TIB across 24 h increased to 8 h, the split and continuous sleep groups performed comparably in tests evaluating vigilance, working memory, executive function, processing speed, subjective sleepiness, and mood. CONCLUSIONS In adolescents, the effects of split sleep on basic cognitive functions vary by the amount of total sleep obtained. As long as the total sleep opportunity across 24 h is within the recommended range, students may fulfill sleep requirements by adopting a split sleep schedule consisting of a shorter period of nocturnal sleep combined with a mid-afternoon nap, without significant impact on basic cognitive functions. CLINICAL TRIAL REGISTRATION NCT04044885.
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Affiliation(s)
- June C Lo
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ruth L F Leong
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Alyssa S C Ng
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - S Azrin Jamaluddin
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ju Lynn Ong
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Shohreh Ghorbani
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - TeYang Lau
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Nicholas I Y N Chee
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Joshua J Gooley
- Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, Singapore
| | - Michael W L Chee
- Centre for Sleep and Cognition, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, Singapore
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13
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Splitting sleep between the night and a daytime nap reduces homeostatic sleep pressure and enhances long-term memory. Sci Rep 2021; 11:5275. [PMID: 33674679 PMCID: PMC7935993 DOI: 10.1038/s41598-021-84625-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/12/2021] [Indexed: 11/09/2022] Open
Abstract
Daytime naps have been linked with enhanced memory encoding and consolidation. It remains unclear how a daily napping schedule impacts learning throughout the day, and whether these effects are the same for well-rested and sleep restricted individuals. We compared memory in 112 adolescents who underwent two simulated school weeks containing 8 or 6.5 h sleep opportunities each day. Sleep episodes were nocturnal or split between nocturnal sleep and a 90-min afternoon nap, creating four experimental groups: 8 h-continuous, 8 h-split, 6.5 h-continuous and 6.5 h-split. Declarative memory was assessed with picture encoding and an educationally realistic factual knowledge task. Splitting sleep significantly enhanced afternoon picture encoding and factual knowledge under both 6.5 h and 8 h durations. Splitting sleep also significantly reduced slow-wave energy during nocturnal sleep, suggesting lower homeostatic sleep pressure during the day. There was no negative impact of the split sleep schedule on morning performance, despite a reduction in nocturnal sleep. These findings suggest that naps could be incorporated into a daily sleep schedule that provides sufficient sleep and benefits learning.
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Lo JC, Twan DCK, Karamchedu S, Lee XK, Ong JL, Van Rijn E, Gooley JJ, Chee MWL. Differential effects of split and continuous sleep on neurobehavioral function and glucose tolerance in sleep-restricted adolescents. Sleep 2020; 42:5316239. [PMID: 30753648 PMCID: PMC6519912 DOI: 10.1093/sleep/zsz037] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 02/07/2019] [Indexed: 12/31/2022] Open
Abstract
Study Objectives Many adolescents are exposed to sleep restriction on school nights. We assessed how different apportionment of restricted sleep (continuous vs. split sleep) influences neurobehavioral function and glucose levels. Methods Adolescents, aged 15–19 years, were evaluated in a dormitory setting using a parallel-group design. Following two baseline nights of 9-hour time-in-bed (TIB), participants underwent either 5 nights of continuous 6.5-h TIB (n = 29) or 5-hour nocturnal TIB with a 1.5-hour afternoon nap (n = 29). After two recovery nights of 9-hour TIB, participants were sleep restricted for another three nights. Sleep was assessed using polysomnography (PSG). Cognitive performance and mood were evaluated three times per day. Oral glucose tolerance tests (OGTT) were conducted on mornings after baseline sleep, recovery sleep, and the third day of each sleep restriction cycle. Results The split sleep group had fewer vigilance lapses, better working memory and executive function, faster processing speed, lower level of subjective sleepiness, and more positive mood, even though PSG-verified total sleep time was less than the continuous sleep group. However, vigilance in both sleep-restricted groups was inferior to adolescents in a prior sample given 9-hour nocturnal TIB. During both cycles of sleep restriction, blood glucose during the OGTT increased by a greater amount in the split sleep schedule compared with persons receiving 6.5-hour continuous sleep. Conclusions In adolescents, modest multinight sleep restriction had divergent negative effects on cognitive performance and glucose levels depending on how the restricted sleep was apportioned. They are best advised to obtain the recommended amount of nocturnal sleep. Trial registration https://clinicaltrials.gov/ct2/show/NCT03333512
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Affiliation(s)
- June C Lo
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Derek C K Twan
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Swathy Karamchedu
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Xuan Kai Lee
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Ju Lynn Ong
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Elaine Van Rijn
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Joshua J Gooley
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
| | - Michael W L Chee
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore
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15
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Cousins JN, Van Rijn E, Ong JL, Chee MWL. A split sleep schedule rescues short-term topographical memory after multiple nights of sleep restriction. Sleep 2020; 42:5306230. [PMID: 30715485 PMCID: PMC6448285 DOI: 10.1093/sleep/zsz018] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 01/03/2019] [Indexed: 11/21/2022] Open
Abstract
Study Objectives Chronic sleep restriction in adolescents is widespread, yet we know little about how to apportion the limited amount of sleep obtained to minimize cognitive impairment: should sleep occur only nocturnally, or be split across separate nocturnal and daytime nap periods? This is particularly relevant to hippocampal-dependent cognitive functions that underpin several aspects of learning. Method We assessed hippocampal function in four groups by evaluating short-term topographical memory with the Four Mountains Test (4MT). All participants began with 9 hours nocturnal time-in-bed (TIB) for 2 days before following different sleep schedules over the next 3 days. Each day, one group had 5 hours nocturnal TIB (5.0h; n = 30), another, 6.5 hours nocturnal TIB (6.5h; n = 29), and a third had 6.5 hours split into 5 hours nocturnal TIB and a 1.5 hour TIB daytime nap (5.0 + 1.5h; n = 29). A control group maintained 9 hours nocturnal TIB (9.0h; n = 30). The 4MT was administered mid-afternoon (1.5 hours after awakening for those who napped). Results Performance of the 5.0h and 6.5h nocturnal TIB groups was significantly impaired relative to the 9.0h control group. Performance of participants on the split- sleep schedule (5.0 + 1.5h) did not significantly differ from controls. Conclusions These findings suggest that hippocampal function is sensitive to moderate multi-night sleep restriction, but deficits can be ameliorated by splitting sleep, at least for a period after waking from a daytime nap. While this split sleep schedule should not be considered a replacement for adequate nocturnal sleep, it appears to benefit the cognitive and neurophysiological functions that underpin learning in those who are chronically sleep deprived.
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Affiliation(s)
- James N Cousins
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore 169857
| | - Elaine Van Rijn
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore 169857
| | - Ju Lynn Ong
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore 169857
| | - Michael W L Chee
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore 169857
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Sleep and Work in ICU Physicians During a Randomized Trial of Nighttime Intensivist Staffing. Crit Care Med 2020; 47:894-902. [PMID: 30985450 DOI: 10.1097/ccm.0000000000003773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVES To compare sleep, work hours, and behavioral alertness in faculty and fellows during a randomized trial of nighttime in-hospital intensivist staffing compared with a standard daytime intensivist model. DESIGN Prospective observational study. SETTING Medical ICU of a tertiary care academic medical center during a randomized controlled trial of in-hospital nighttime intensivist staffing. PATIENTS Twenty faculty and 13 fellows assigned to rotations in the medical ICU during 2012. INTERVENTIONS As part of the parent study, there was weekly randomization of staffing model, stratified by 2-week faculty rotation. During the standard staffing model, there were in-hospital residents, with a fellow and faculty member available at nighttime by phone. In the intervention, there were in-hospital residents with an in-hospital nighttime intensivist. Fellows and faculty completed diaries detailing their sleep, work, and well-being; wore actigraphs; and performed psychomotor vigilance testing daily. MEASUREMENTS AND MAIN RESULTS Daily sleep time (mean hours [SD]) was increased for fellows and faculty in the intervention versus control (6.7 [0.3] vs 6.0 [0.2]; p < 0.001 and 6.7 [0.1] vs 6.4 [0.2]; p < 0.001, respectively). In-hospital work duration did not differ between the models for fellows or faculty. Total hours of work done at home was different for both fellows and faculty (0.1 [< 0.1] intervention vs 1.0 [0.1] control; p < 0.001 and 0.2 [< 0.1] intervention vs 0.6 [0.1] control; p < 0.001, respectively). Psychomotor vigilance testing did not demonstrate any differences. Measures of well-being including physical exhaustion and alertness were improved in faculty and fellows in the intervention staffing model. CONCLUSIONS Although no differences were measured in patient outcomes between the two staffing models, in-hospital nighttime intensivist staffing was associated with small increases in total sleep duration for faculty and fellows, reductions in total work hours for fellows only, and improvements in subjective well-being for both groups. Staffing models should consider how work duration, sleep, and well-being may impact burnout and sustainability.
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Cousins JN, van Rijn E, Ong JL, Wong KF, Chee MWL. Does splitting sleep improve long-term memory in chronically sleep deprived adolescents? NPJ SCIENCE OF LEARNING 2019; 4:8. [PMID: 31285846 PMCID: PMC6599038 DOI: 10.1038/s41539-019-0047-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 05/23/2019] [Indexed: 06/09/2023]
Abstract
Sleep aids the encoding and consolidation of declarative memories, but many adolescents do not obtain the recommended amount of sleep each night. After a normal night of sleep, there is abundant evidence that a daytime nap enhances the consolidation of material learned before sleep and also improves the encoding of new information upon waking. However, it remains unclear how learning is affected when sleep is split between nocturnal and daytime nap periods during a typical school week of restricted sleep. We compared long-term memory in 58 adolescents who underwent two simulated school weeks of suboptimal continuous (6.5 h nocturnal sleep opportunity) or split sleep (5 h nocturnal sleep +1.5 h daytime nap at 14:00). In the first week, participants encoded pictures in the late afternoon on Day 5 and were tested after 2-nights of recovery sleep. On 3 consecutive days in the second week, participants learned about six species of amphibians in the morning, and six different amphibians in the late afternoon. Testing was performed in the evening following a night of recovery sleep. In the first week, the split sleep group recognized more pictures. In the second week, they remembered more facts about species learned in the afternoon. Groups did not differ for species learned in the morning. This suggests that under conditions of sleep restriction, a split sleep schedule benefits learning after a nap opportunity without impairing morning learning, despite less preceding nocturnal sleep. While not replacing adequate nocturnal sleep, a split sleep schedule may be beneficial for chronically sleep restricted learners.
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Affiliation(s)
- James N. Cousins
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, 169857 Singapore
| | - Elaine van Rijn
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, 169857 Singapore
| | - Ju Lynn Ong
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, 169857 Singapore
| | - Kian F. Wong
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, 169857 Singapore
| | - Michael W. L. Chee
- Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, 169857 Singapore
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18
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McHill AW, Wright KP. Cognitive Impairments during the Transition to Working at Night and on Subsequent Night Shifts. J Biol Rhythms 2019; 34:432-446. [PMID: 31072264 DOI: 10.1177/0748730419848552] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Demands of modern society force many work operations into the night when the internal circadian timekeeping system is promoting sleep. The combination of disturbed daytime sleep and circadian misalignment, which is common in overnight shift work, decreases cognitive performance, yet how performance may differ across multiple consecutive nights of shift work is not fully understood. Therefore, the primary aim of this study was to use a simulated night-shift protocol to examine the cognitive performance and ratings of sleepiness and clear-headedness across the hours of a typical daytime shift, a first night shift with an afternoon nap and extended wakefulness, and 2 subsequent overnight shifts. We tested the hypothesis that cognitive performance would be worse on the first night shift as compared with the baseline and subsequent nighttime shifts and that performance during nighttime shifts would be reduced as compared with the baseline daytime shift. Fifteen healthy adults (6 men) were studied in the 6-day in-laboratory protocol. Results showed that working during the night increased subjective sleepiness and decreased clear-headedness and performance on the Psychomotor Vigilance Task (i.e., slower median, fastest and slowest reaction times, and increased attentional lapses), Stroop color word task (decreased number of correct responses and slower median reaction time), and calculation addition performance task (decreased number attempted and correct). Furthermore, we observed limited evidence of sleepiness, clear-headedness, or performance adaptation across subsequent nights of simulated night work. Our findings demonstrate that night-shift work, regardless of whether it is the first night shift with a nap and extended wakefulness or subsequent night shifts, decreases performance and clear-headedness as compared with the day shift.
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Affiliation(s)
- Andrew W McHill
- Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, Oregon
| | - Kenneth P Wright
- Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado
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19
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Mogilever NB, Zuccarelli L, Burles F, Iaria G, Strapazzon G, Bessone L, Coffey EBJ. Expedition Cognition: A Review and Prospective of Subterranean Neuroscience With Spaceflight Applications. Front Hum Neurosci 2018; 12:407. [PMID: 30425628 PMCID: PMC6218582 DOI: 10.3389/fnhum.2018.00407] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 09/21/2018] [Indexed: 01/10/2023] Open
Abstract
Renewed interest in human space exploration has highlighted the gaps in knowledge needed for successful long-duration missions outside low-Earth orbit. Although the technical challenges of such missions are being systematically overcome, many of the unknowns in predicting mission success depend on human behavior and performance, knowledge of which must be either obtained through space research or extrapolated from human experience on Earth. Particularly in human neuroscience, laboratory-based research efforts are not closely connected to real environments such as human space exploration. As caves share several of the physical and psychological challenges of spaceflight, underground expeditions have recently been developed as a spaceflight analog for astronaut training purposes, suggesting that they might also be suitable for studying aspects of behavior and cognition that cannot be fully examined under laboratory conditions. Our objective is to foster a bi-directional exchange between cognitive neuroscientists and expedition experts by (1) describing the cave environment as a worthy space analog for human research, (2) reviewing work conducted on human neuroscience and cognition within caves, (3) exploring the range of topics for which the unique environment may prove valuable as well as obstacles and limitations, (4) outlining technologies and methods appropriate for cave use, and (5) suggesting how researchers might establish contact with potential expedition collaborators. We believe that cave expeditions, as well as other sorts of expeditions, offer unique possibilities for cognitive neuroscience that will complement laboratory work and help to improve human performance and safety in operational environments, both on Earth and in space.
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Affiliation(s)
| | | | - Ford Burles
- Department of Psychology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Giuseppe Iaria
- Department of Psychology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Giacomo Strapazzon
- Institute of Mountain Emergency Medicine, Eurac Research - Institute of Mountain Emergency Medicine, Bolzano, Italy
| | - Loredana Bessone
- Directorate of Human and Robotics, Exploration, European Space Agency, Köln, Germany
| | - Emily B J Coffey
- Department of Psychology, Concordia University, Montreal, QC, Canada
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McHill AW, Hull JT, Wang W, Czeisler CA, Klerman EB. Chronic sleep curtailment, even without extended (>16-h) wakefulness, degrades human vigilance performance. Proc Natl Acad Sci U S A 2018; 115:6070-6075. [PMID: 29784810 PMCID: PMC6003377 DOI: 10.1073/pnas.1706694115] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Millions of individuals routinely remain awake for more than 18 h daily, which causes performance decrements. It is unknown if these functional impairments are the result of that extended wakefulness or from the associated shortened sleep durations. We therefore examined changes in objective reaction time performance and subjective alertness in a 32-d inpatient protocol in which participants were scheduled to wakefulness durations below 16 h while on a 20-h "day," with randomization into standard sleep:wake ratio (1:2) or chronic sleep restriction (CSR) ratio (1:3.3) conditions. This protocol allowed determination of the contribution of sleep deficiency independent of extended wakefulness, since individual episodes of wakefulness in the CSR condition were only 15.33 h in duration (less than the usual 16 h of wakefulness in a 24-h day) and sleep episodes were 4.67 h in duration each cycle. We found that chronic short sleep duration, even without extended wakefulness, doubled neurobehavioral reaction time performance and increased lapses of attention fivefold, yet did not uniformly decrease self-reported alertness. Further, these impairments in neurobehavioral performance were worsened during the circadian night and were not recovered during the circadian day, indicating that the deleterious effect from the homeostatic buildup of CSR is expressed even during the circadian promotion of daytime arousal. These findings reveal a fundamental aspect of human biology: Chronic insufficient sleep duration equivalent to 5.6 h of sleep opportunity per 24 h impairs neurobehavioral performance and self-assessment of alertness, even without extended wakefulness.
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Affiliation(s)
- Andrew W McHill
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115;
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR 97239
| | - Joseph T Hull
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115
| | - Wei Wang
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115
| | - Charles A Czeisler
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115
| | - Elizabeth B Klerman
- Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115;
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115
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Davy J, Göbel M. The effects of extended nap periods on cognitive, physiological and subjective responses under simulated night shift conditions. Chronobiol Int 2017; 35:169-187. [PMID: 29144168 DOI: 10.1080/07420528.2017.1391277] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Extended nap opportunities have been effective in maintaining alertness in the context of extended night shifts (+12 h). However, there is limited evidence of their efficacy during 8-h shifts. Thus, this study explored the effects of extended naps on cognitive, physiological and perceptual responses during four simulated, 8-h night shifts. In a laboratory setting, 32 participants were allocated to one of three conditions. All participants completed four consecutive, 8-h night shifts, with the arrangements differing by condition. The fixed night condition worked from 22h00 to 06h00, while the nap early group worked from 20h00 to 08h00 and napped between 00h00 and 03h20. The nap late group worked from 00h00 to 12h00 and napped between 04h00 and 07h20. Nap length was limited to 3 hours and 20 minutes. Participants performed a simple beading task during each shift, while also completing six to eight test batteries roughly every 2 h. During each shift, six test batteries were completed, in which the following measures were taken. Performance indicators included beading output, eye accommodation time, choice reaction time, visual vigilance, simple reaction time, processing speed and object recognition, working memory, motor response time and tracking performance. Physiological measures included heart rate and tympanic temperature, whereas subjective sleepiness and reported sleep length and quality while outside the laboratory constituted the self reported measures. Both naps reduced subjective sleepiness but did not alter the circadian and homeostatic-related changes in cognitive and physiological measures, relative to the fixed night condition. Additionally, there was evidence of sleep inertia following each nap, which resulted in transient reductions in certain perceptual cognitive performance measures. The present study suggested that there were some benefits associated with including an extended nap during 8-h night shifts. However, the effects of sleep inertia need to be effectively managed to ensure that post-nap alertness and performance is maintained.
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Affiliation(s)
- Jonathan Davy
- a Department of Human Kinetics and Ergonomics , Rhodes University , Grahamstown , South Africa
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Morabito C, Guarnieri S, Catizone A, Schiraldi C, Ricci G, Mariggiò MA. Transient increases in intracellular calcium and reactive oxygen species levels in TCam-2 cells exposed to microgravity. Sci Rep 2017; 7:15648. [PMID: 29142208 PMCID: PMC5688167 DOI: 10.1038/s41598-017-15935-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/02/2017] [Indexed: 11/14/2022] Open
Abstract
The effects of microgravity on functions of the human body are well described, including alterations in the male and female reproductive systems. In the present study, TCam-2 cells, which are considered a good model of mitotically active male germ cells, were used to investigate intracellular signalling and cell metabolism during exposure to simulated microgravity, a condition that affects cell shape and cytoskeletal architecture. After a 24 hour exposure to simulated microgravity, TCam-2 cells showed 1) a decreased proliferation rate and a delay in cell cycle progression, 2) increased anaerobic metabolism accompanied by increased levels of intracellular Ca2+, reactive oxygen species and superoxide anion and modifications in mitochondrial morphology. Interestingly, all these events were transient and were no longer evident after 48 hours of exposure. The presence of antioxidants prevented not only the effects described above but also the modifications in cytoskeletal architecture and the activation of the autophagy process induced by simulated microgravity. In conclusion, in the TCam-2 cell model, simulated microgravity activated the oxidative machinery, triggering transient macroscopic cell events, such as a reduction in the proliferation rate, changes in cytoskeleton-driven shape and autophagy activation.
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Affiliation(s)
- C Morabito
- Department of Neuroscience, Imaging and Clinical Sciences and Centro Scienze dell' Invecchiamento e Medicina Traslazionale (CeSI-MeT), "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - S Guarnieri
- Department of Neuroscience, Imaging and Clinical Sciences and Centro Scienze dell' Invecchiamento e Medicina Traslazionale (CeSI-MeT), "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - A Catizone
- Section of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic and Orthopaedic Medicine, "Sapienza" University of Rome, Rome, Italy
| | - C Schiraldi
- Department of Experimental Medicine, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy
| | - G Ricci
- Department of Experimental Medicine, Università degli Studi della Campania "Luigi Vanvitelli", Naples, Italy
| | - M A Mariggiò
- Department of Neuroscience, Imaging and Clinical Sciences and Centro Scienze dell' Invecchiamento e Medicina Traslazionale (CeSI-MeT), "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.
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Dudley KA, Weng J, Sotres-Alvarez D, Simonelli G, Cespedes Feliciano E, Ramirez M, Ramos AR, Loredo JS, Reid KJ, Mossavar-Rahmani Y, Zee PC, Chirinos DA, Gallo LC, Wang R, Patel SR. Actigraphic Sleep Patterns of U.S. Hispanics: The Hispanic Community Health Study/Study of Latinos. Sleep 2017; 40:2758299. [PMID: 28364514 DOI: 10.1093/sleep/zsw049] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Study objective To assess the extent to which objective sleep patterns vary among U.S. Hispanics/Latinos. Methods We assessed objective sleep patterns in 2087 participants of the Hispanic Community Health Study/Study of Latinos from 6 Hispanic/Latino subgroups aged 18-64 years who underwent 7 days of wrist actigraphy. Results The age- and sex-standardized mean (SE) sleep duration was 6.82 (0.05), 6.72 (0.07), 6.61 (0.07), 6.59 (0.06), 6.57 (0.10), and 6.44 (0.09) hr among individuals of Mexican, Cuban, Dominican, Central American, Puerto Rican, and South American heritage, respectively. Sleep maintenance efficiency ranged from 89.2 (0.2)% in Mexicans to 86.5 (0.4)% in Puerto Ricans, while the sleep fragmentation index ranged from 19.7 (0.3)% in Mexicans to 24.2 (0.7)% in Puerto Ricans. In multivariable models adjusted for age, sex, season, socioeconomic status, lifestyle habits, and comorbidities, these differences persisted. Conclusions There are important differences in actigraphically measured sleep across U.S. Hispanic/Latino heritages. Individuals of Mexican heritage have longer and more consolidated sleep, while those of Puerto Rican heritage have shorter and more fragmented sleep. These differences may have clinically important effects on health outcomes.
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Affiliation(s)
- Katherine A Dudley
- Division of Pulmonary, Critical Care, and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, MA.,Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston MA
| | - Jia Weng
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston MA
| | - Daniela Sotres-Alvarez
- Collaborative Studies Coordinating Center, Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC
| | - Guido Simonelli
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston MA.,Walter Reed Army Institute of Research, Behavioral Biology Branch, Center for Military Psychiatry and Neuroscience, Silver Spring, MD
| | - Elizabeth Cespedes Feliciano
- Departments of Nutrition and Epidemiology, Harvard TH Chan School of Public Health, Boston, MA.,Kaiser Permanente, Division of Research, Oakland, CA
| | - Maricelle Ramirez
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston MA
| | | | - Jose S Loredo
- Division of Pulmonary and Critical Care Medicine, University of California San Diego, San Diego, CA
| | - Kathryn J Reid
- Department of Neurology, Northwestern University, Chicago, IL
| | - Yasmin Mossavar-Rahmani
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY
| | - Phyllis C Zee
- Department of Neurology, Northwestern University, Chicago, IL
| | | | - Linda C Gallo
- Department of Psychology, San Diego State University, San Diego, CA
| | - Rui Wang
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston MA.,Department of Biostatistics, Harvard TH Chan School of Public Health, Boston, MA
| | - Sanjay R Patel
- Division of Pulmonary, Critical Care, and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, MA.,Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston MA
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24
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Fang Z, Rao H. Imaging homeostatic sleep pressure and circadian rhythm in the human brain. J Thorac Dis 2017; 9:E495-E498. [PMID: 28616320 PMCID: PMC5465131 DOI: 10.21037/jtd.2017.03.168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 03/17/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Zhuo Fang
- Laboratory of Applied Brain and Cognitive Sciences, Shanghai International Studies University, Shanghai 200000, China
- Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Hengyi Rao
- Laboratory of Applied Brain and Cognitive Sciences, Shanghai International Studies University, Shanghai 200000, China
- Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
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25
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Basner M, Dinges DF, Shea JA, Small DS, Zhu J, Norton L, Ecker AJ, Novak C, Bellini LM, Volpp KG. Sleep and Alertness in Medical Interns and Residents: An Observational Study on the Role of Extended Shifts. Sleep 2017; 40:3045870. [PMID: 28329124 PMCID: PMC5806581 DOI: 10.1093/sleep/zsx027] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Study Objectives Fatigue from sleep loss is a risk to physician and patient safety, but objective data on physician sleep and alertness on different duty hour schedules is scarce. This study objectively quantified differences in sleep duration and alertness between medical interns working extended overnight shifts and residents not or rarely working extended overnight shifts. Methods Sleep-wake activity of 137 interns and 87 PGY-2/3 residents on 2-week Internal Medicine and Oncology rotations was assessed with wrist-actigraphy. Alertness was assessed daily with a brief Psychomotor Vigilance Test (PVT) and the Karolinska Sleepiness Scale. Results Interns averaged 6.93 hours (95% confidence interval [CI] 6.84-7.03 hours) sleep per 24 hours across shifts, significantly less than residents not working overnight shifts (7.18 hours, 95% CI 7.06-7.30 hours, p = .007). Interns obtained on average 2.19 hours (95% CI 2.02-2.36 hours) sleep during on-call nights (17.5% obtained no sleep). Alertness was significantly lower on mornings after on-call nights compared to regular shifts (p < .001). Naps between 9 am and 6 pm on the first day post-call were frequent (90.8%) and averaged 2.84 hours (95% CI 2.69-3.00 hours), but interns still slept 1.66 hours less per 24 hours (95% CI 1.56-1.76 hours) compared to regular shift days (p < .001). Sleep inertia significantly affected alertness in the 60 minutes after waking on-call. Conclusions Extended overnight shifts increase the likelihood of chronic sleep restriction in interns. Reduced levels of alertness after on-call nights need to be mitigated. A systematic comparison of sleep, alertness, and safety outcomes under current and past duty hour rules is encouraged.
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Affiliation(s)
- Mathias Basner
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - David F Dinges
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Judy A Shea
- Center for Health Equity Research and Promotion, Philadelphia Corporal Michael J. Cresencz Veterans Affairs Medical Center, Philadelphia, PA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Leonard Davis Institute Center for Health Incentives and Behavioral Economics, University of Pennsylvania, Philadelphia, PA
| | - Dylan S Small
- Leonard Davis Institute Center for Health Incentives and Behavioral Economics, University of Pennsylvania, Philadelphia, PA
- Department of Statistics, The Wharton School, University of Pennsylvania, Philadelphia, PA
| | - Jingsan Zhu
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Leonard Davis Institute Center for Health Incentives and Behavioral Economics, University of Pennsylvania, Philadelphia, PA
| | - Laurie Norton
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Leonard Davis Institute Center for Health Incentives and Behavioral Economics, University of Pennsylvania, Philadelphia, PA
| | - Adrian J Ecker
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Cristina Novak
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Leonard Davis Institute Center for Health Incentives and Behavioral Economics, University of Pennsylvania, Philadelphia, PA
| | - Lisa M Bellini
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Kevin G Volpp
- Center for Health Equity Research and Promotion, Philadelphia Corporal Michael J. Cresencz Veterans Affairs Medical Center, Philadelphia, PA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Leonard Davis Institute Center for Health Incentives and Behavioral Economics, University of Pennsylvania, Philadelphia, PA
- Department of Health Care Management, The Wharton School, University of Pennsylvania, Philadelphia, PA
- Department of Medical Ethics and Health Policy, University of Pennsylvania, Philadelphia PA
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26
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Zhou X, Sargent C, Kosmadopoulos A, Darwent D, Dawson D, Roach GD. Do split sleep/wake schedules reduce or increase sleepiness for continuous operations? ACCIDENT; ANALYSIS AND PREVENTION 2017; 99:434-439. [PMID: 26549869 DOI: 10.1016/j.aap.2015.10.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 10/20/2015] [Accepted: 10/23/2015] [Indexed: 06/05/2023]
Abstract
This study compared the impact of split and consolidated sleep/wake schedules on subjective sleepiness during the biological day and biological night. This was achieved using a between-group design involving two forced desynchrony protocols: consolidated sleep/wake and split sleep/wake. Both protocols included 7×28-h days with 9.33h in bed and 18.67h of wake each day. While the consolidated sleep/wake protocol had 1×9.33-h sleep opportunity and 1×18.67-h wake period each day, the split sleep/wake protocol had 2×4.67-h sleep opportunities and 2×9.33-h wake periods each day. For both protocols, subjective sleepiness was measured using the Karolinska Sleepiness Scale every 2.5h during wake. A total of 29 healthy adult males participated, with 13 in the consolidated sleep/wake group (mean age=22.5 yrs) and 16 in the split sleep/wake group (mean age=22.6 yrs). On average, subjective sleepiness during wake periods of the split condition was significantly higher than that during the first half of wake periods of the consolidated condition, but was similar to the level during the second half. These findings were observed for wake periods that occurred during both the biological day and biological night. Previous data have shown that cognitive impairment at night is lower for split schedules than consolidated schedules, but the current data indicate that feelings of sleepiness are greater for split schedules than consolidated schedules for at least half of the time awake. Thus, it should be explained to people operating split sleep/wake schedules that although they may perform well, they are likely to feel sleepy.
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Affiliation(s)
- Xuan Zhou
- Central Queensland University, Appleton Institute for Behavioural Science, PO Box 42, Goodwood, SA 5034, Australia.
| | - Charli Sargent
- Central Queensland University, Appleton Institute for Behavioural Science, PO Box 42, Goodwood, SA 5034, Australia.
| | - Anastasi Kosmadopoulos
- Central Queensland University, Appleton Institute for Behavioural Science, PO Box 42, Goodwood, SA 5034, Australia.
| | - David Darwent
- Central Queensland University, Appleton Institute for Behavioural Science, PO Box 42, Goodwood, SA 5034, Australia.
| | - Drew Dawson
- Central Queensland University, Appleton Institute for Behavioural Science, PO Box 42, Goodwood, SA 5034, Australia.
| | - Gregory D Roach
- Central Queensland University, Appleton Institute for Behavioural Science, PO Box 42, Goodwood, SA 5034, Australia.
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27
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Skornyakov E, Shattuck NL, Winser MA, Matsangas P, Sparrow AR, Layton ME, Gabehart RJ, Van Dongen HPA. Sleep and performance in simulated Navy watch schedules. ACCIDENT; ANALYSIS AND PREVENTION 2017; 99:422-427. [PMID: 26691014 DOI: 10.1016/j.aap.2015.11.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 10/10/2015] [Accepted: 11/20/2015] [Indexed: 06/05/2023]
Abstract
To operate Navy ships 24h per day, watchstanding is needed around the clock, with watch periods reflecting a variety of rotating or fixed shift schedules. The 5/15 watch schedule cycles through watch periods with 5h on, 15h off watch, such that watches occur 4h earlier on the clock each day - that is, the watches rotate backward. The timing of sleep varies over 4-day cycles, and sleep is split on some days to accommodate nighttime watchstanding. The 3/9 watch schedule cycles through watch periods with 3h on, 9h off watch, allowing for consistent sleep timing over days. In some sections of the 3/9 watch schedule, sleep may need to be split to accommodate nighttime watchstanding. In both the 5/15 and 3/9 watch schedules, four watch sections alternate to cover the 24h of the day. Here we compared sleep duration, psychomotor vigilance and subjective sleepiness in simulated sections of the 5/15 and 3/9 watch schedules. Fifteen healthy male subjects spent 6 consecutive days (5 nights) in the laboratory. Sleep opportunities were restricted to an average of 6.5h daily. Actigraphically estimated sleep duration was 5.6h per watch day on average, with no significant difference between watch sections. Sleep duration was not reduced when sleep opportunities were split. Psychomotor vigilance degraded over watch days, and tended to be more variable in the 5/15 than in the 3/9 watch sections. These laboratory-based findings suggest that Navy watch schedules are associated with cumulative sleep loss and a build-up of fatigue across days. The fixed watch periods of the 3/9 watch schedule appear to yield more stable performance than the backward rotating watch periods of the 5/15 watch schedule. Optimal performance may require longer and more consistent daily opportunities for sleep than are typically obtained in Navy operations.
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Affiliation(s)
- Elena Skornyakov
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, PO Box 1495, Spokane, WA 99210-1495, USA.
| | - Nita L Shattuck
- Naval Postgraduate School, 1411 Cunningham Road, Monterey, CA 93943, USA.
| | - Michael A Winser
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, PO Box 1495, Spokane, WA 99210-1495, USA.
| | | | - Amy R Sparrow
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, PO Box 1495, Spokane, WA 99210-1495, USA.
| | - Matthew E Layton
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, PO Box 1495, Spokane, WA 99210-1495, USA.
| | - Rylie J Gabehart
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, PO Box 1495, Spokane, WA 99210-1495, USA.
| | - Hans P A Van Dongen
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, PO Box 1495, Spokane, WA 99210-1495, USA.
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Roach GD, Zhou X, Darwent D, Kosmadopoulos A, Dawson D, Sargent C. Are two halves better than one whole? A comparison of the amount and quality of sleep obtained by healthy adult males living on split and consolidated sleep-wake schedules. ACCIDENT; ANALYSIS AND PREVENTION 2017; 99:428-433. [PMID: 26574119 DOI: 10.1016/j.aap.2015.10.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 10/06/2015] [Accepted: 10/13/2015] [Indexed: 06/05/2023]
Abstract
The aim of this study was to compare the quantity/quality of sleep obtained by people living on split and consolidated sleep-wake schedules. The study had a between-groups design, with 13 participants in a consolidated condition (all males, mean age of 22.5yr) and 16 participants in a split condition (all males, mean age of 22.6yr). Both conditions employed forced desynchrony protocols with the activity:rest ratio set at 2:1, but the consolidated condition had one sleep-wake cycle every 28h (9.33+18.67), while the split condition had one sleep-wake cycle every 14h (4.67+9.33). Sleep was assessed using polysomnography. Participants in the split and consolidated conditions obtained 4.0h of sleep per 14h and 7.6h of sleep per 28h, respectively. Some differences between the groups indicated that sleep quality was lower in the split condition than the consolidated condition: the split sleeps had longer sleep onset latency (9.7 vs. 4.3min), more arousals (7.4 vs. 5.7 per hour in bed), and a greater percentage of stage 1 sleep (4.1% vs. 3.1%), than the consolidated sleeps. Other differences between the groups indicated that sleep quality was higher in the split condition than the consolidated condition: the split sleeps had a lower percentage of wake after sleep onset sleep (11.7% vs. 17.6%), and a greater percentage of slow wave sleep (30.2% vs. 23.8%), than the consolidated sleeps. These results indicate that the split schedule was not particularly harmful, and may have actually been beneficial, to sleep. Split work-rest schedules can be socially disruptive, but their use may be warranted in work settings where shiftworkers are separated from their normal family/social lives (e.g., fly-in fly-out mining) or where the need for family/social time is secondary to the task (e.g., emergency response to natural disasters).
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Affiliation(s)
- Gregory D Roach
- Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia.
| | - Xuan Zhou
- Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia.
| | - David Darwent
- Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia.
| | - Anastasi Kosmadopoulos
- Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia.
| | - Drew Dawson
- Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia.
| | - Charli Sargent
- Appleton Institute for Behavioural Science, Central Queensland University, PO Box 42, Goodwood, SA 5034, Australia.
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29
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Dorrian J, Grant C, Banks S. An industry case study of 'stand-up' and 'sleepover' night shifts in disability support: Residential support worker perspectives. APPLIED ERGONOMICS 2017; 58:110-118. [PMID: 27633203 DOI: 10.1016/j.apergo.2016.05.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 04/13/2016] [Accepted: 05/25/2016] [Indexed: 06/06/2023]
Abstract
PURPOSE Residential support workers (RSW) engage in overnight "sleepover" shifts as well as more traditional "standup" night shifts. While research has investigated the consequences of night and on-call work for sleep in other industries, the sleep of RSW has not been evaluated. METHOD In a single-provider case study, six employees completed the Pittsburgh Sleep Quality Index (PSQI), the Depression Anxiety Stress Scale (DASS), a 2-week sleep diary, and a 30 min interview, and four also completed the Shirom-Melamed Burnout Measure (SMBM). RESULTS Participants reported sleep of poor quality, low-mild DASS scores, and evidence of SMBM scores that were elevated relative to norms. Sleep was significantly lower (p < 0.01) following "standup" shifts (mean = 4.1, SD = 1.8 h) and during "sleepover" shifts (mean = 5.6, SD = 2.0 h) compared to non-shift nights (mean = 7.3, SD = 2.3 h). Interviews suggested that sleep fluctuates with level of patient care, colleague assistance, stress, and the quality of the sleeping environment (including bed comfort, light, noise and perceived safety). CONCLUSIONS Findings suggest that this group have sleep that is insufficient and of poor quality and that they may be at risk of burnout. Consideration of ways to optimise sleeping conditions at work (e.g. through noise or stress reduction) would be beneficial. Research in this area has the potential to facilitate improvements in health and safety in this growing industry.
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Affiliation(s)
- Jillian Dorrian
- Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of South Australia City East Campus, P7-35 Playford Building, Frome Rd, Adelaide, 5000, Australia.
| | - Crystal Grant
- Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of South Australia City East Campus, P7-35 Playford Building, Frome Rd, Adelaide, 5000, Australia.
| | - Siobhan Banks
- Centre for Sleep Research, School of Psychology, Social Work and Social Policy, University of South Australia City East Campus, P7-35 Playford Building, Frome Rd, Adelaide, 5000, Australia.
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30
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Barclay NL, Myachykov A. Sustained wakefulness and visual attention: moderation by chronotype. Exp Brain Res 2016; 235:57-68. [PMID: 27624836 PMCID: PMC5225193 DOI: 10.1007/s00221-016-4772-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 09/06/2016] [Indexed: 11/15/2022]
Abstract
Introduction Attentional networks are sensitive to sleep deprivation and increased time awake. However, existing evidence is inconsistent and may be accounted for by differences in chronotype or time-of-day. We examined the effects of sustained wakefulness over a normal “socially constrained” day (following 18 h of sustained wakefulness), following a night of normal sleep, on visual attention as a function of chronotype. Methods Twenty-six good sleepers (mean age 25.58; SD 4.26; 54 % male) completed the Attention Network Test (ANT) at two time points (baseline at 8 am; following 18-h sustained wakefulness at 2 am). The ANT provided mean reaction times (RTs), error rates, and the efficiency of three attentional networks—alerting, orienting, and executive control/conflict. The Morningness–Eveningness Questionnaire measured chronotype. Results Mean RTs were longer at time 2 compared to time 1 for those with increasing eveningness; the opposite was true for morningness. However, those with increasing morningness exhibited longer RT and made more errors, on incongruent trials at time 2 relative to those with increasing eveningness. There were no significant main effects of time or chronotype (or interactions) on attentional network scores. Conclusion Sustained wakefulness produced differential effects on visual attention as a function of chronotype. Whilst overall our results point to an asynchrony effect, this effect was moderated by flanker type. Participants with increasing eveningness outperformed those with increasing morningness on incongruent trials at time 2. The preservation of executive control in evening-types following sustained wakefulness is likely driven by differences in circadian phase between chronotypes across the day.
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Affiliation(s)
- Nicola L Barclay
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK.
| | - Andriy Myachykov
- Department of Psychology, Faculty of Health and Life Sciences, Northumbria University, Newcastle, UK.,Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russia
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Faraut B, Andrillon T, Vecchierini MF, Leger D. Napping: A public health issue. From epidemiological to laboratory studies. Sleep Med Rev 2016; 35:85-100. [PMID: 27751677 DOI: 10.1016/j.smrv.2016.09.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 09/05/2016] [Accepted: 09/05/2016] [Indexed: 12/28/2022]
Abstract
Sleep specialists have proposed measures to counteract the negative short- and long-term consequences of sleep debt, and some have suggested the nap as a potential and powerful "public health tool". Here, we address this countermeasure aspect of napping viewed as an action against sleep deprivation rather than an action associated with poor health. We review the physiological functions that have been associated positively with napping in both public health and clinical settings (sleep-related accidents, work and school, and cardiovascular risk) and in laboratory-based studies with potential public health issues (cognitive performance, stress, immune function and pain sensitivity). We also discuss the circumstances in which napping-depending on several factors, including nap duration, frequency, and age-could be a potential public health tool and a countermeasure for sleep loss in terms of reducing accidents and cardiovascular events and improving sleep-restriction-sensitive working performance. However, the impact of napping and the nature of the sleep stage(s) involved still need to be evaluated, especially from the perspective of coping strategies in populations with chronic sleep debt, such as night and shift workers.
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Affiliation(s)
- Brice Faraut
- Université Paris Descartes, Sorbonne Paris Cité, APHP, Hôtel Dieu de Paris, Centre du Sommeil et de la Vigilance, EA 7330 VIFASOM, Paris, France.
| | - Thomas Andrillon
- École Normale Supérieure-PSL Research University, Laboratoire de Sciences Cognitives et Psycholinguistique (UMR8554, ENS, EHESS, CNRS), Paris, France
| | - Marie-Françoise Vecchierini
- Université Paris Descartes, Sorbonne Paris Cité, APHP, Hôtel Dieu de Paris, Centre du Sommeil et de la Vigilance, EA 7330 VIFASOM, Paris, France
| | - Damien Leger
- Université Paris Descartes, Sorbonne Paris Cité, APHP, Hôtel Dieu de Paris, Centre du Sommeil et de la Vigilance, EA 7330 VIFASOM, Paris, France.
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32
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Barkaszi I, Takács E, Czigler I, Balázs L. Extreme Environment Effects on Cognitive Functions: A Longitudinal Study in High Altitude in Antarctica. Front Hum Neurosci 2016; 10:331. [PMID: 27445768 PMCID: PMC4928492 DOI: 10.3389/fnhum.2016.00331] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/16/2016] [Indexed: 11/16/2022] Open
Abstract
This paper focuses on the impact of long-term Antarctic conditions on cognitive processes. Behavioral responses and event-related potentials were recorded during an auditory distraction task and an attention network paradigm. Participants were members of the over-wintering crew at Concordia Antarctic Research Station. Due to the reduced partial pressure of oxygen this environment caused moderate hypoxia. Beyond the hypoxia, the fluctuation of sunshine duration, isolation and confinement were the main stress factors of this environment. We compared 6 measurement periods completed during the campaign. Behavioral responses and N1/MMN (mismatch negativity), N1, N2, P3, RON (reorientation negativity) event-related potential components have been analyzed. Reaction time decreased in both tasks in response to repeated testing during the course of mission. The alerting effect increased, the inhibition effect decreased and the orienting effect did not change in the ANT task. Contrary to our expectations the N2, P3, RON components related to the attentional functions did not show any significant changes. Changes attributable to early stages of information processing were observed in the ANT task (N1 component) but not in the distraction task (N1/MMN). The reaction time decrements and the N1 amplitude reduction in ANT task could be attributed to sustained effect of practice. We conclude that the Antarctic conditions had no negative impacts on cognitive activity despite the presence of numerous stressors.
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Affiliation(s)
- Irén Barkaszi
- Environmental Adaptation and Space Research Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of SciencesBudapest, Hungary
- Department of Experimental Psychology, Institute of Psychology, Debrecen UniversityDebrecen, Hungary
| | - Endre Takács
- Environmental Adaptation and Space Research Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of SciencesBudapest, Hungary
- Faculty of Education and Psychology, Eötvös Loránd UniversityBudapest, Hungary
| | - István Czigler
- Environmental Adaptation and Space Research Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of SciencesBudapest, Hungary
- Faculty of Education and Psychology, Eötvös Loránd UniversityBudapest, Hungary
| | - László Balázs
- Environmental Adaptation and Space Research Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of SciencesBudapest, Hungary
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Hilditch CJ, Short M, Van Dongen HPA, Centofanti SA, Dorrian J, Kohler M, Banks S. Sleep inertia during a simulated 6-h on/6-h off fixed split duty schedule. Chronobiol Int 2016; 33:685-96. [PMID: 27078176 DOI: 10.3109/07420528.2016.1167724] [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]
Abstract
Sleep inertia is a safety concern for shift workers returning to work soon after waking up. Split duty schedules offer an alternative to longer shift periods, but introduce additional wake-ups and may therefore increase risk of sleep inertia. This study investigated sleep inertia across a split duty schedule. Sixteen participants (age range 21-36 years; 10 females) participated in a 9-day laboratory study with two baseline nights (10 h time in bed, [TIB]), four 24-h periods of a 6-h on/6-h off split duty schedule (5-h TIB in off period; 10-h TIB per 24 h) and two recovery nights. Two complementary rosters were evaluated, with the timing of sleep and wake alternating between the two rosters (2 am/2 pm wake-up roster versus 8 am/8 pm wake-up roster). At 2, 17, 32 and 47 min after scheduled awakening, participants completed an 8-min inertia test bout, which included a 3-min psychomotor vigilance test (PVT-B), a 3-min Digit-Symbol Substitution Task (DSST), the Karolinska Sleepiness Scale (KSS), and the Samn-Perelli Fatigue Scale (SP-Fatigue). Further testing occurred every 2 h during scheduled wakefulness. Performance was consistently degraded and subjective sleepiness/fatigue was consistently increased during the inertia testing period as compared to other testing times. Morning wake-ups (2 am and 8 am) were associated with higher levels of sleep inertia than later wake-ups (2 pm and 8 pm). These results suggest that split duty workers should recognise the potential for sleep inertia after waking, especially during the morning hours.
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Affiliation(s)
- Cassie J Hilditch
- a Centre for Sleep Research , University of South Australia , Adelaide , South Australia , Australia
| | - Michelle Short
- a Centre for Sleep Research , University of South Australia , Adelaide , South Australia , Australia.,b School of Psychology , Flinders University , Adelaide , South Australia , Australia
| | - Hans P A Van Dongen
- c Sleep and Performance Research Center , Washington State University , Spokane , WA , USA.,d Elson S. Floyd College of Medicine , Washington State University , Spokane , WA , USA
| | - Stephanie A Centofanti
- a Centre for Sleep Research , University of South Australia , Adelaide , South Australia , Australia
| | - Jillian Dorrian
- a Centre for Sleep Research , University of South Australia , Adelaide , South Australia , Australia
| | - Mark Kohler
- a Centre for Sleep Research , University of South Australia , Adelaide , South Australia , Australia
| | - Siobhan Banks
- a Centre for Sleep Research , University of South Australia , Adelaide , South Australia , Australia
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Ramakrishnan S, Wesensten NJ, Balkin TJ, Reifman J. A Unified Model of Performance: Validation of its Predictions across Different Sleep/Wake Schedules. Sleep 2016; 39:249-62. [PMID: 26518594 DOI: 10.5665/sleep.5358] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 08/08/2015] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Historically, mathematical models of human neurobehavioral performance developed on data from one sleep study were limited to predicting performance in similar studies, restricting their practical utility. We recently developed a unified model of performance (UMP) to predict the effects of the continuum of sleep loss-from chronic sleep restriction (CSR) to total sleep deprivation (TSD) challenges-and validated it using data from two studies of one laboratory. Here, we significantly extended this effort by validating the UMP predictions across a wide range of sleep/wake schedules from different studies and laboratories. METHODS We developed the UMP on psychomotor vigilance task (PVT) lapse data from one study encompassing four different CSR conditions (7 d of 3, 5, 7, and 9 h of sleep/night), and predicted performance in five other studies (from four laboratories), including different combinations of TSD (40 to 88 h), CSR (2 to 6 h of sleep/night), control (8 to 10 h of sleep/night), and nap (nocturnal and diurnal) schedules. RESULTS The UMP accurately predicted PVT performance trends across 14 different sleep/wake conditions, yielding average prediction errors between 7% and 36%, with the predictions lying within 2 standard errors of the measured data 87% of the time. In addition, the UMP accurately predicted performance impairment (average error of 15%) for schedules (TSD and naps) not used in model development. CONCLUSIONS The unified model of performance can be used as a tool to help design sleep/wake schedules to optimize the extent and duration of neurobehavioral performance and to accelerate recovery after sleep loss.
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Affiliation(s)
- Sridhar Ramakrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, US Army Medical Research and Materiel Command, Fort Detrick, MD
| | - Nancy J Wesensten
- Department of Behavioral Biology, Walter Reed Army Institute of Research, Silver Spring, MD
| | - Thomas J Balkin
- Department of Behavioral Biology, Walter Reed Army Institute of Research, Silver Spring, MD
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, US Army Medical Research and Materiel Command, Fort Detrick, MD
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Goel N, Basner M, Dinges DF. Phenotyping of Neurobehavioral Vulnerability to Circadian Phase During Sleep Loss. Methods Enzymol 2015; 552:285-308. [DOI: 10.1016/bs.mie.2014.10.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Jackson ML, Banks S, Belenky G. Investigation of the effectiveness of a split sleep schedule in sustaining sleep and maintaining performance. Chronobiol Int 2014; 31:1218-30. [DOI: 10.3109/07420528.2014.957305] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kosmadopoulos A, Sargent C, Darwent D, Zhou X, Dawson D, Roach GD. The effects of a split sleep-wake schedule on neurobehavioural performance and predictions of performance under conditions of forced desynchrony. Chronobiol Int 2014; 31:1209-17. [PMID: 25222348 DOI: 10.3109/07420528.2014.957763] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Extended wakefulness, sleep loss, and circadian misalignment are factors associated with an increased accident risk in shiftwork. Splitting shifts into multiple shorter periods per day may mitigate these risks by alleviating prior wake. However, the effect of splitting the sleep-wake schedule on the homeostatic and circadian contributions to neurobehavioural performance and subjective assessments of one's ability to perform are not known. Twenty-nine male participants lived in a time isolation laboratory for 13 d, assigned to one of two 28-h forced desynchrony (FD) schedules. Depending on the assigned schedule, participants were provided the same total time in bed (TIB) each FD cycle, either consolidated into a single period (9.33 h TIB) or split into two equal halves (2 × 4.67 h TIB). Neurobehavioural performance was regularly assessed with a psychomotor vigilance task (PVT) and subjectively-assessed ability was measured with a prediction of performance on a visual analogue scale. Polysomnography was used to assess sleep, and core body temperature was recorded to assess circadian phase. On average, participants obtained the same amount of sleep in both schedules, but those in the split schedule obtained more slow wave sleep (SWS) on FD days. Mixed-effects ANOVAs indicated no overall difference between the standard and split schedules in neurobehavioural performance or predictions of performance. Main effects of circadian phase and prior wake were present for both schedules, such that performance and subjective ratings of ability were best around the circadian acrophase, worst around the nadir, and declined with increasing prior wake. There was a schedule by circadian phase interaction for all neurobehavioural performance metrics such that performance was better in the split schedule than the standard schedule around the nadir. There was no such interaction for predictions of performance. Performance during the standard schedule was significantly better than the split schedule at 2 h of prior wake, but declined at a steeper rate such that the schedules converged by 4.5-7 h of prior wake. Overall, the results indicate that when the total opportunity for sleep per day is satisfactory, a split sleep-wake schedule is not detrimental to sleep or performance. Indeed, though not reflected in subjective assessments of performance capacity, splitting the schedule may be of some benefit, given its reduction of neurobehavioural impairment at night and its association with increased SWS. Therefore, for some industries that require operations to be sustained around the clock, implementing a split work-rest schedule may be of assistance.
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Affiliation(s)
- Anastasi Kosmadopoulos
- Appleton Institute for Behavioural Science, Central Queensland University , Adelaide, South Australia , Australia and
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Psychological and behavioral changes during confinement in a 520-day simulated interplanetary mission to mars. PLoS One 2014; 9:e93298. [PMID: 24675720 PMCID: PMC3968121 DOI: 10.1371/journal.pone.0093298] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 02/09/2014] [Indexed: 11/19/2022] Open
Abstract
Behavioral health risks are among the most serious and difficult to mitigate risks of confinement in space craft during long-duration space exploration missions. We report on behavioral and psychological reactions of a multinational crew of 6 healthy males confined in a 550 m(3) chamber for 520 days during the first Earth-based, high-fidelity simulated mission to Mars. Rest-activity of crewmembers was objectively measured throughout the mission with wrist-worn actigraphs. Once weekly throughout the mission crewmembers completed the Beck Depression Inventory-II (BDI-II), Profile of Moods State short form (POMS), conflict questionnaire, the Psychomotor Vigilance Test (PVT-B), and series of visual analogue scales on stress and fatigue. We observed substantial inter-individual differences in the behavioral responses of crewmembers to the prolonged mission confinement and isolation. The crewmember with the highest average POMS total mood disturbance score throughout the mission also reported symptoms of depression in 93% of mission weeks, which reached mild-to-moderate levels in >10% of mission weeks. Conflicts with mission control were reported five times more often than conflicts among crewmembers. Two crewmembers who had the highest ratings of stress and physical exhaustion accounted for 85% of the perceived conflicts. One of them developed a persistent sleep onset insomnia with ratings of poor sleep quality, which resulted in chronic partial sleep deprivation, elevated ratings of daytime tiredness, and frequent deficits in behavioral alertness. Sleep-wake timing was altered in two other crewmembers, beginning in the first few months of the mission and persisting throughout. Two crewmembers showed neither behavioral disturbances nor reports of psychological distress during the 17-month period of mission confinement. These results highlight the importance of identifying behavioral, psychological, and biological markers of characteristics that predispose prospective crewmembers to both effective and ineffective behavioral reactions during the confinement of prolonged spaceflight, to inform crew selection, training, and individualized countermeasures.
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Liu R, Liu X, Zee PC, Hou L, Zheng Z, Wei Y, Du J. Association between sleep quality and C-reactive protein: results from national health and nutrition examination survey, 2005-2008. PLoS One 2014; 9:e92607. [PMID: 24663098 PMCID: PMC3963926 DOI: 10.1371/journal.pone.0092607] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 02/24/2014] [Indexed: 12/03/2022] Open
Abstract
Objective Our objective was to explore the association between poor sleep quality and hs_CRP in an adult U.S. population. Methods This study focused on 9,317 participants in the National Health and Nutrition Examination Survey (NHANES) from 2005–2008 who were aged 20–85 years, completed a sleep disorder questionnaire, and had available information on serum hs_CRP. Sleep quality was classified into three categories (good, moderate, poor) based on the responses of participants to the NHANES sleep disorder questionnaire. High CRP was defined as hs-CRP >1 md/dL. Linear regression model was applied to investigate the association between poor sleep quality and log-transformed hs_CRP. And logistic regression model was fitted to evaluate the association between sleep quality and the risk of high CRP. Results Females were more likely to report poor sleep quality than males (26% vs. 19%, p<0.0001). Each sleep disorder was significantly associated with increased hs_CRP and correlative to other sleep disorders. In fully-adjusted linear regression model, poor sleep quality was significantly associated with elevated hs_CRP (log transformed) among the overall sample and in females only (β = 0.10, se = 0.03, p<0.01 and β = 0.13, se = 0.04, p<0.01, respectively). In fully-adjusted logistics regression model, poor sleep quality was linked with risk of high CRP(OR: 1.42, 95%CI: 1.15–1.76 in overall sample and OR: 1.59, 95%CI: 1.18–2.14 in females, respectively). Conclusion We found that poor sleep quality was independently associated with elevated hs_CRP in females but not in males in a U.S. adult population.
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Affiliation(s)
- Rong Liu
- Beijing An Zhen Hospital, Capital Medical University, The Key Laboratory of Remodeling-related Cardiovascular Diseases, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
- Mary Ann and J. Milburn Smith Child Health Research Program, Department of Pediatrics, Northwestern University Feinberg School of Medicine and Ann & Robert H. Lurie Children's Hospital of Chicago and Children's Hospital of Chicago Research Center, Chicago, Illinois, United States of America
- * E-mail: (RL); (JD)
| | - Xin Liu
- Mary Ann and J. Milburn Smith Child Health Research Program, Department of Pediatrics, Northwestern University Feinberg School of Medicine and Ann & Robert H. Lurie Children's Hospital of Chicago and Children's Hospital of Chicago Research Center, Chicago, Illinois, United States of America
| | - Phyllis C. Zee
- Department of Neurology and Sleep Medicine Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Lifang Hou
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Zheng Zheng
- Department of Neurobiology, Beijing Institute of Geriatrics, Beijing Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Yongxiang Wei
- Department of Otorhinolaryngology, Beijing An Zhen Hospital, Capital Medical University, Beijing, China
| | - Jie Du
- Beijing An Zhen Hospital, Capital Medical University, The Key Laboratory of Remodeling-related Cardiovascular Diseases, Ministry of Education, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
- * E-mail: (RL); (JD)
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Shea JA, Dinges DF, Small DS, Basner M, Zhu J, Norton L, Ecker AJ, Novak C, Bellini LM, Dine CJ, Mollicone DJ, Volpp KG. A randomized trial of a three-hour protected nap period in a medicine training program: sleep, alertness, and patient outcomes. ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 2014; 89:452-459. [PMID: 24448046 DOI: 10.1097/acm.0000000000000144] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
PURPOSE Protected sleep periods for internal medicine interns have previously resulted in increased amount slept and improved cognitive alertness but required supplemental personnel. The authors evaluated intern and patient outcomes associated with protected nocturnal nap periods of three hours that are personnel neutral. METHOD Randomized trial at Philadelphia Veterans Affairs Medical Center (PVAMC) Medical Service and Hospital of the University of Pennsylvania (HUP) Oncology Unit. During 2010-2011, four-week blocks were randomly assigned to a standard intern schedule (extended duty overnight shifts of up to 30 hours), or sequential protected sleep periods (phone sign-out midnight to 3:00 AM [early shift] intern 1; 3:00 to 6:00 AM [late shift] intern 2). Participants wore wrist Actiwatches, completed sleep diaries, and performed daily assessments of behavioral alertness. Between-group comparisons of means and proportions controlled for within-person correlations. RESULTS HUP interns had significantly longer sleep durations during both early (2.40 hours) and late (2.44 hours) protected periods compared with controls (1.55 hours, P < .0001). At PVAMC sleep duration was longer only for the late shift group (2.40 versus 1.90 hours, P < .036). Interns assigned to either protected period were significantly less likely to have call nights with no sleep and had fewer attentional lapses on the Psychomotor Vigilance Test. Differences in patient outcomes between standard schedule months versus intervention months were not observed. CONCLUSIONS Protected sleep periods of three hours resulted in more sleep during call and reductions in periods of prolonged wakefulness, providing a plausible alternative to 16-hour shifts.
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Affiliation(s)
- Judy A Shea
- Dr. Shea is professor of medicine-clinician educator and associate dean of medical education research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Dinges is professor of psychology in psychiatry and chief of the division of sleep and chronobiology, department of psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Small is associate professor, department of statistics, The Wharton School, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Basner is assistant professor of sleep and chronobiology in psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Mr. Zhu is assistant director of data analytics, LDI Center for Health Incentives and Behavioral Economics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Ms. Norton is research project manager, CHERP, Philadelphia VA Medical Center, and CHIBE, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Mr. Ecker is a senior information technology project leader, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Ms. Novak was research coordinator, CHERP, Philadelphia VA Medical Center, and CHIBE, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, at the time this study was conducted. Currently she is a second-year medical student, Temple University School of Medicine, Philadelphia, Pennsylvania. Dr. Bellini is professor of medicine, and vice chair for education, department of medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Dine is assistant professor of medicine, division of pulmonary and critical care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Mollicone is president and CEO of Pulsar Informatics, Inc., Philadelphia, Pennsylvania. Dr. Volpp is staff ph
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McCauley P, Kalachev LV, Mollicone DJ, Banks S, Dinges DF, Van Dongen HPA. Dynamic circadian modulation in a biomathematical model for the effects of sleep and sleep loss on waking neurobehavioral performance. Sleep 2013; 36:1987-97. [PMID: 24293775 DOI: 10.5665/sleep.3246] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Recent experimental observations and theoretical advances have indicated that the homeostatic equilibrium for sleep/wake regulation--and thereby sensitivity to neurobehavioral impairment from sleep loss--is modulated by prior sleep/wake history. This phenomenon was predicted by a biomathematical model developed to explain changes in neurobehavioral performance across days in laboratory studies of total sleep deprivation and sustained sleep restriction. The present paper focuses on the dynamics of neurobehavioral performance within days in this biomathematical model of fatigue. Without increasing the number of model parameters, the model was updated by incorporating time-dependence in the amplitude of the circadian modulation of performance. The updated model was calibrated using a large dataset from three laboratory experiments on psychomotor vigilance test (PVT) performance, under conditions of sleep loss and circadian misalignment; and validated using another large dataset from three different laboratory experiments. The time-dependence of circadian amplitude resulted in improved goodness-of-fit in night shift schedules, nap sleep scenarios, and recovery from prior sleep loss. The updated model predicts that the homeostatic equilibrium for sleep/wake regulation--and thus sensitivity to sleep loss--depends not only on the duration but also on the circadian timing of prior sleep. This novel theoretical insight has important implications for predicting operator alertness during work schedules involving circadian misalignment such as night shift work.
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Affiliation(s)
- Peter McCauley
- Sleep and Performance Research Center, Washington State University, Spokane, WA ; Department of Mathematical Sciences, University of Montana, Missoula, MT
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McDonald J, Potyk D, Fischer D, Parmenter B, Lillis T, Tompkins L, Bowen A, Grant D, Lamp A, Belenky G. Napping on the Night Shift: A Study of Sleep, Performance, and Learning in Physicians-in-Training. J Grad Med Educ 2013; 5:634-8. [PMID: 24455014 PMCID: PMC3886464 DOI: 10.4300/jgme-d-12-00324.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 03/22/2013] [Accepted: 05/22/2013] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Physicians in training experience fatigue from sleep loss, high workload, and working at an adverse phase of the circadian rhythm, which collectively degrades task performance and the ability to learn and remember. To minimize fatigue and sustain performance, learning, and memory, humans generally need 7 to 8 hours of sleep in every 24-hour period. METHODS In a naturalistic, within-subjects design, we studied 17 first- and second-year internal medicine residents working in a tertiary care medical center, rotating between day shift and night float every 4 weeks. We studied each resident for 2 weeks while he/she worked the day shift and for 2 weeks while he/she worked the night float, objectively measuring sleep by wrist actigraphy, vigilance by the Psychomotor Vigilance Task test, and visual-spatial and verbal learning and memory by the Brief Visuospatial Memory Test-Revised and the Rey Auditory-Verbal Learning Test. RESULTS Residents, whether working day shift or night float, slept approximately 7 hours in every 24-hour period. Residents, when working day shift, consolidated their sleep into 1 main sleep period at night. Residents working night float split their sleep, supplementing their truncated daytime sleep with nighttime on-duty naps. There was no difference in vigilance or learning and memory, whether residents worked day shift or night float. CONCLUSIONS Off-duty sleep supplemented with naps while on duty appears to be an effective strategy for sustaining vigilance, learning, and memory when working night float.
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Basner M, Rao H, Goel N, Dinges DF. Sleep deprivation and neurobehavioral dynamics. Curr Opin Neurobiol 2013; 23:854-63. [PMID: 23523374 PMCID: PMC3700596 DOI: 10.1016/j.conb.2013.02.008] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 02/18/2013] [Accepted: 02/19/2013] [Indexed: 11/18/2022]
Abstract
Lifestyles involving sleep deprivation are common, despite mounting evidence that both acute total sleep deprivation and chronically restricted sleep degrade neurobehavioral functions associated with arousal, attention, memory and state stability. Current research suggests dynamic differences in the way the central nervous system responds to acute versus chronic sleep restriction, which is reflected in new models of sleep-wake regulation. Chronic sleep restriction likely induces long-term neuromodulatory changes in brain physiology that could explain why recovery from it may require more time than from acute sleep loss. High intraclass correlations in neurobehavioral responses to sleep loss suggest that these trait-like differences are phenotypic and may include genetic components. Sleep deprivation induces changes in brain metabolism and neural activation that involve distributed networks and connectivity.
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Affiliation(s)
- Mathias Basner
- Unit of Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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Paterson JL, Dorrian J, Ferguson SA, Jay SM, Dawson D. What happens to mood, performance and sleep in a laboratory study with no sleep deprivation? Sleep Biol Rhythms 2013; 11:200-209. [PMID: 24839396 DOI: 10.1111/sbr.12023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
There are few studies examining changes in waking function in a laboratory environment with no sleep deprivation and mood has been largely overlooked in this context. The present study examined changes in mood, performance, sleep and sleepiness in the laboratory study with no sleep deprivation. Nineteen participants (10M, 9F; 22y ± 4.2y) were given nine 9h sleep opportunities (2300-0800). Every two hours during wake, participants completed the Mood Scale II, a 10-minute Psychomotor Vigilance Task and measures of sleepiness and fatigue. Sleep was monitored using an electroencephalographic montage. Findings revealed significant negative mood change, performance impairment, reduced total sleep time and sleep efficiency (all p < .05). These findings suggest that the laboratory environment or procedural factors may impair mood, performance and sleep. These findings may have implications for interpreting impairments in mood, performance and sleep when observed in laboratory environments.
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Affiliation(s)
- Jessica L Paterson
- Central Queensland University, Appleton Institute, 44 Greenhill Road, Wayville SA 5034
| | - Jill Dorrian
- University of South Australia, School of Psychology, Social Work and Social Policy, GPO Box 2471, Adelaide SA 5001
| | - Sally A Ferguson
- Central Queensland University, Appleton Institute, 44 Greenhill Road, Wayville SA 5034
| | - Sarah M Jay
- Central Queensland University, Appleton Institute, 44 Greenhill Road, Wayville SA 5034
| | - Drew Dawson
- Central Queensland University, Appleton Institute, 44 Greenhill Road, Wayville SA 5034
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Gander P, van den Berg M, Mulrine H, Signal L, Mangie J. Circadian adaptation of airline pilots during extended duration operations between the USA and Asia. Chronobiol Int 2013; 30:963-72. [DOI: 10.3109/07420528.2013.790042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Satterfield BC, Van Dongen HP. Occupational fatigue, underlying sleep and circadian mechanisms, and approaches to fatigue risk management. FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR 2013. [DOI: 10.1080/21641846.2013.798923] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Goel N, Basner M, Rao H, Dinges DF. Circadian rhythms, sleep deprivation, and human performance. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 119:155-90. [PMID: 23899598 DOI: 10.1016/b978-0-12-396971-2.00007-5] [Citation(s) in RCA: 215] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Much of the current science on, and mathematical modeling of, dynamic changes in human performance within and between days is dominated by the two-process model of sleep-wake regulation, which posits a neurobiological drive for sleep that varies homeostatically (increasing as a saturating exponential during wakefulness and decreasing in a like manner during sleep), and a circadian process that neurobiologically modulates both the homeostatic drive for sleep and waking alertness and performance. Endogenous circadian rhythms in neurobehavioral functions, including physiological alertness and cognitive performance, have been demonstrated using special laboratory protocols that reveal the interaction of the biological clock with the sleep homeostatic drive. Individual differences in circadian rhythms and genetic and other components underlying such differences also influence waking neurobehavioral functions. Both acute total sleep deprivation and chronic sleep restriction increase homeostatic sleep drive and degrade waking neurobehavioral functions as reflected in sleepiness, attention, cognitive speed, and memory. Recent evidence indicating a high degree of stability in neurobehavioral responses to sleep loss suggests that these trait-like individual differences are phenotypic and likely involve genetic components, including circadian genes. Recent experiments have revealed both sleep homeostatic and circadian effects on brain metabolism and neural activation. Investigation of the neural and genetic mechanisms underlying the dynamically complex interaction between sleep homeostasis and circadian systems is beginning. A key goal of this work is to identify biomarkers that accurately predict human performance in situations in which the circadian and sleep homeostatic systems are perturbed.
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Affiliation(s)
- Namni Goel
- Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Bahammam AS, Sharif MM, Spence DW, Pandi-Perumal SR. Sleep architecture of consolidated and split sleep due to the dawn (Fajr) prayer among Muslims and its impact on daytime sleepiness. Ann Thorac Med 2012; 7:36-41. [PMID: 22347349 PMCID: PMC3277040 DOI: 10.4103/1817-1737.91560] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 09/04/2011] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND: Muslims are required to wake up early to pray (Fajr) at dawn (approximately one and one-half hours before sunrise). Some Muslims wake up to pray Fajr and then sleep until it is time to work (split sleep), whereas others sleep continuously (consolidated sleep) until work time and pray Fajr upon awakening. AIM: To objectively assess sleep architecture and daytime sleepiness in consolidated and split sleep due to the Fajr prayer. SETTING AND DESIGN: A cross-sectional, single-center observational study in eight healthy male subjects with a mean age of 32.0 ± 2.4 years. METHODS: The participants spent three nights in the Sleep Disorders Center (SDC) at King Khalid University Hospital, where they participated in the study, which included (1) a medical checkup and an adaptation night, (2) a consolidated sleep night, and (3) a split-sleep night. Polysomnography (PSG) was conducted in the SDC following the standard protocol. Participants went to bed at 11:30 PM and woke up at 7:00 AM in the consolidated sleep protocol. In the split-sleep protocol, participants went to bed at 11:30 PM, woke up at 3:30 AM for 45 minutes, went back to bed at 4:15 AM, and finally woke up at 7:45 AM. PSG was followed by a multiple sleep latency test to assess the daytime sleepiness of the participants. RESULTS: There were no differences in sleep efficiency, the distribution of sleep stages, or daytime sleepiness between the two protocols. CONCLUSION: No differences were detected in sleep architecture or daytime sleepiness in the consolidated and split-sleep schedules when the total sleep duration was maintained.
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Affiliation(s)
- Ahmed S Bahammam
- University Sleep Disorders Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Wright KP, Bogan RK, Wyatt JK. Shift work and the assessment and management of shift work disorder (SWD). Sleep Med Rev 2012; 17:41-54. [PMID: 22560640 DOI: 10.1016/j.smrv.2012.02.002] [Citation(s) in RCA: 242] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 11/25/2022]
Abstract
Nearly 20% of the labor force worldwide, work shifts that include work hours outside 07:00 h to 18:00 h. Shift work is common in many occupations that directly affect the health and safety of others (e.g., protective services, transportation, healthcare), whereas quality of life, health, and safety during shift work and the commute home can affect workers in any field. Increasing evidence indicates that shift-work schedules negatively influence worker physiology, health, and safety. Shift work disrupts circadian sleep and alerting cycles, resulting in disturbed daytime sleep and excessive sleepiness during the work shift. Moreover, shift workers are at risk for shift work disorder (SWD). This review focuses on shift work and the assessment and management of sleepiness and sleep disruption associated with shift work schedules and SWD. Management strategies include approaches to promote sleep, wakefulness, and adaptation of the circadian clock to the imposed work schedule. Additional studies are needed to further our understanding of the mechanisms underlying the health risks of shift work, understanding which shift workers are at most risk of SWD, to investigate treatment options that address the health and safety burdens associated with shift work and SWD, and to further develop and assess the comparative effectiveness of countermeasures and treatment options.
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Affiliation(s)
- Kenneth P Wright
- Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado at Boulder, 1725 Pleasant Street, Boulder, CO 80309, USA.
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Lützhöft M, Grech MR, Porathe T. Information Environment, Fatigue, and Culture in the Maritime Domain. ACTA ACUST UNITED AC 2011. [DOI: 10.1177/1557234x11410391] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Maritime shipping operates within a complex operational setting and incorporates many types of workplaces and work roles. The maritime domain has been a bit slower than other complex domains in its research and development of human factors and ergonomics application. The problem remains that the operator is continuously being excluded from the loop, which increases the probability of shipboard errors and accidents. This chapter begins by providing a general introduction to the maritime domain and its unique characteristics and is followed by a section on the information environment on the bridge. The section on the information environment on the bridge highlights the importance of integrating the end user into the bridge system and how technology must provide intuitive information at the right level of complexity at the right time. The main focus of this chapter is then split into two areas of current high significance: fatigue on board and maritime culture (also incorporating safety culture issues). Fatigue on board is of major concern, and most studies indicate that a systems approach must be adopted. This approach should account for aspects such as the number of personnel, trip length, frequency and duration of port visits, and shift planning. Within the area of maritime culture, multiculturalism and the way it is managed on board ships, including shipboard practices, affect safety. In the area of safety culture, three recommendations are central: (a) increase compliance with regulations, (b) implement a safety management system, and (c) implement a behavioral safety system. In general, this review indicates that more data are needed on human-technology-organizational issues in the maritime domain.
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