Sleep

11 Key excerpts on "Sleep"

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  The Principles and Practice of Human Physiology

  • O.G. Edholm(Author)
  • 2012(Publication Date)
  • Academic Press

    (Publisher)

  A mother may wake at the first soft cries of her baby but remain aSleep when a dog barks. Thus, Sleep is a state of reduced responsiveness to the environment and of altered mental function-ing but, nonetheless, a state in which some information processing of sensory input continues. Functions of Sleep The ubiquity of Sleep-wakefulness rhythms and the many differences between REM and N R E M Sleep have provided the basis for speculation about the overall needs for Sleep and, lately, about the separate functions of the different kinds of Sleep. Early suggestions that dreaming and REM Sleep were essential for psychological wellbeing in man prompted many investiga-tions into the nature of this requirement (Hartmann, 1973). However, as we Sleep 515 shall see later in this chapter (p. 520), the absence of REM Sleep for prolonged periods in man has not consistently led to any recognizable behavioural changes. The finding of an increased proportion of REM Sleep in neonates led to speculation that REM Sleep serves an ontogenetic function, organizing the developing central nervous system (Roffwarg et al., 1966) and the oculomotor system in particular (Berger, 1969). So far, these are no more than working hypotheses. The decrease in body temperature by an active process of heat loss during Sleep, the inhibition of Cortisol and of adrenaline secretion at a time when growth hormone, prolactin and, at puberty, also LH secretion are increased —these findings are all consistent with Sleep, and particularly delta-wave Sleep, being a period of restoration and anabolism after increased catabo-lism during wakefulness. Perhaps Sleep is needed after many hours of wakefulness because of fatigue in the neural mechanisms subserving selec-tive attention and the maintenance of psychological defences, that is, of the most highly integrated functions of the central nervous system.

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  Physiologic Nature Of Sleep, The

  • Ricardo A Velluti, Pier Luigi Parmeggiani(Authors)
  • 2005(Publication Date)
  • ICP

    (Publisher)

  Sleep is a very heterogeneous state. Different psycho-physiological phases alternate during each Sleep cycle. At present, states are classified as rapid eye movement (REM) Sleep appearing at the end of each Sleep cycle, and light (S1 and S2) and deep Sleep (S3 and S4) constituting non-REM Sleep (NREM). These phases are characterized by specific EEG landmarks (see Chapter 5). Moreover, new animal and human studies have shown extremely low frequency oscillations ( < 1 Hz) associated to NREM Sleep, delta and spindles activity (Steriade, 1997; Acherman and Borbely, 1998) 1 [email protected] 535 536 C. M. Portas and fast gamma frequencies, cortical oscillations associated with REM Sleep similar to the ones observed in the waking state (e.g. Steriade and Amzica, 1996). Imaging studies have also shown distinct patterns of activation in REM and NREM Sleep: REM Sleep is mainly associated with reactivation of fronto-limbic areas and deactivation of prefrontal regions, while NREM Sleep is characterized by a global deactivation (Maquet et al. , 1996; Braun et al. , 1997). Thus, it is crucial to grant full consideration to the way Sleep stage physi-ology relates to distinctive cognitive activities. This chapter reviews the cur-rent knowledge on sensory information processing and mentation/dreaming taking place during Sleep. Perception There is no direct access to the mental state of a Sleeping person. Whatever the Sleeper experiences can only be reported upon awakening. The applica-tion of techniques like EEG and especially evoked potentials during Sleep allowed us to analyze immediate response to stimuli presentation in the form of brain waves. Studies of evoked potentials The accessibility of the auditory system during Sleep explains why audi-tory perception is the sensory modality more exploited during Sleep. More limited information exists for sensory processing in modalities other than auditory, such as like somatosensory and visual.

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  Sleep Apnea

  Current Diagnosis and Treatment

  • W. J. Randerath, B. M. Sanner, V. K. Somers, J. J. F. Herth(Authors)
  • 2006(Publication Date)
  • S. Karger

    (Publisher)

  Abstract Sleep has a restorative function which is more than rest. Sleep is an active process which follows its own program with a sequence of different Sleep stages and autonomous nervous system functions related to them. Slow wave Sleep is mainly related to physical recreation with humoral and neuro-endocrine excretions activated. REM Sleep is mainly but not exclusively related to mental recreation with associated dream-ing and memory functions. The autonomous nervous system with ventilation, cardiocirculatory, vascular and temperature regulation differs between slow wave Sleep and REM Sleep. More regular control is found in slow wave Sleep and more variability is found in REM Sleep. The Sleep processes follow a well-described temporal pattern with Sleep cycles of a duration between 80 and 11 0 min.The Sleep process itself is embedded in the circadian rhythm and occurs naturally during the dark phase of the day with a mean duration of 7–8 h. In order to study Sleep disorders, the knowledge about physiological Sleep, physiological effects of Sleep deprivation, and autonomic and endocrine functions associated with it, is essential. The key question for Sleep physiology, why we Sleep, is still unanswered. It is well studied that many restorative functions are linked to the Sleep process. Physical recre-ation, endocrine and immune functions are closely linked to Sleep. Mental restoration, memory consolidation, mood and behavior are also dependent on a healthy and undisturbed Sleep. Our knowledge about the mechanisms of Sleep-wake states is increasing even if their neuro-anatomical locations still have not been found [1]. All physiological functions are embedded in the circadian day-night cycle. The Sleep-wake cycle is closely linked to the circadian cycle and both influence each other. For the newborn child, the adaptation of the Sleep-wake cycle to the circadian cycle takes some time and is part of the develop-ment process.

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  Basic sleep Mechanisms

  • Olga Petre-Quadens(Author)
  • 2012(Publication Date)
  • Academic Press

    (Publisher)

  ADULT HUMAN Sleep STATES This page intentionally left blank CHAPTER TWELVE An Introduction to Sleep 1 WILLIAM C DEMENT MERRILL M. MITLER The purpose of this paper is essentially pedagogic. We will try to lay some groundwork for understanding the articles that follow and to explicate a few of the principles of Sleep research, at least as we view them at Stanford University. For the most part, we will be presenting descriptions and definitions of Sleep phenomena and some details of the organization of Sleep. The material will be presented roughly in an historical context and the reader will discern, in order, three major themes. First, Sleep and wakefulness may be thought of as cyclic fluctuations in behavior throughout the day. Second, organisms partition their existence among three entirely separate and unique states. Third, Sleep research can profit from a process view of the states of existence, such that each state is considered as a collection of processes. Adopting such a viewpoint will allow each process to be analytically studied. Preparation of this manuscript was supported by National Institute of Mental Health Grant MH 13860, National Institute of Health Grant NS 10727, National Aeronautics and Space Administration Grant NGR 05-020-168. WCD is supported by Career Develop-ment Award MH 5804 and MMM is supported by NIH Grant MH 8304. 271 272 William C. Dement and Memll M. Mitler Sleep and wakefulness are essentially functions of the whole organism vastly extended in the temporal dimension. Scientific observation is ordinarily either cross-sectional or longitudinal, but the very essence of most Sleep re-search is that it is simultaneously longitudinal and cross-sectional. In many fields, undue concentration upon mechanism and function often occurs somewhat prematurely and tends to undermine the necessary attempt at overall careful open-eyed observation without preconceptions.

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  Memory in Mind and Brain

  • Oleg V. Khlevniuk, Vadim A. Staklo(Authors)
  • 1983(Publication Date)
  • Yale University Press

    (Publisher)

  Health reflects and ultimately depends upon satisfactory synchronization of the entire array of the body's functional rhythms. This synchronization is accomplished within the brain, which has its own intrinsically generated rhythms that are likewise subject to influence by internal bodily and externally imposed stim-uli and demands. The Sleep-wake cycle reflects one of the major functional rhythms of the brain, and as noted in the first epigraph, the REM dreaming phase of Sleep has been established as a third major brain-mind state—a window of opportunity for inquiry into mind/brain questions. With the use of modern electroencephalo-graph and polygraph instrumentation, it is possible to identify two alternating major stages of Sleep: rapid eye movement (REM) and non-REM Sleep. There are four depth levels of non-dreaming Sleep (NREM) that are qualitatively similar. Typical visual dreaming oc-curs during the REM or dream periods. Thus the Sleep phase of the circadian (twenty-four-hour) Sleep-wake cycle contains a REM-NREM ultradian (less-than-twenty-four-hour) cycle. Kleitman (1963) regarded the latter as representing a basic rest-activity cycle. REM periods occur at approximately ninety-minute intervals. Usu-ally there are four or five REM periods of roughly twenty minutes' duration during each night's Sleep, usually shorter earlier and lon-ger later in the Sleep period. The ninety-minute ultradian rhythm seen during Sleep may continue during waking hours, but with quite different psychologic and behavioral manifestations such as movement, eating, drinking, and smoking (Friedman and Fisher 129 BRAIN, COGNITIVE NEUROSCIENCE: THE SECOND KEY 1967). The period of this ninety-minute ultradian rhythm lies be-tween the much shorter ones represented by cardiac rate (approxi-mately one second) and respiration (approximately four seconds) and the much longer ones (twenty-four hours to thirty or ninety days) to be mentioned below.

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  Sleep & Dreaming

  Origins, Nature and Functions

  • D. Cohen, H. J. Eysenck(Authors)
  • 2013(Publication Date)
  • Pergamon

    (Publisher)

  REM Sleep is a salient biological marker for intense psychological experience in man and, in all likelihood, in all the higher species. Comparative and developmental data also suggest that REM Sleep is one of those characteristics which serves to define our phylogenetic continuity with both our human ancestors, forerunners, and predecessors. That a phylogenetic perspective for psychological approaches to dreaming seems both desirable and unavoidable is suggested by recent developments in psychology and physiology. First, there is evidence of a strong genetic basis for individual differences in general intelligence, cognitive style, and temperament (Buss and Plomin, 1975; Jensen, 1972). Second, there is growing evidence for the hypothesis that there are marked differences across species in biological preparedness for cognitive, affective, and instrumental behaviors (Seligman, 1970). Third, it is now patently clear that we can no longer consider the nervous system merely as a passive, reflective switchboard-type mechanism. Single cell and electrophysio-logical recordings, as well as behavioral and cognitive studies, clearly indicate that nervous functioning, even during Sleep, is spontaneously active. Together, these behavior genetic, comparative, and electrophysiological data constitute an empirical basis for the view that intellectual functions (including dreaming) are strongly influenced by endogenous characteristics of the organism. It is evident that biologically determined wiring greatly affects the rate, selectivity, permanence, and utility of what is learned and also how that learning is expressed cognitively, affectively, and instrumentally. A number of implications follow. We must seriously question the assumption that the individual is best conceptualized as a dependent variable subject to the influence of environmental independent variables.

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  Teaching the World to Sleep

  Psychological and Behavioural Assessment and Treatment Strategies for People with Sleeping Problems and Insomnia

  • David R. Lee(Author)
  • 2023(Publication Date)
  • Routledge

    (Publisher)

  Chapter 1

  The science of Sleep

  DOI: 10.4324/9781003367680-1

  There have been many books written about Sleep, the varying theories about its nature and purpose, informed from multiple angles (adults, infants, animals, and even plants!) over many decades. As stated in the introduction, the purpose of this book is to deliver information that is current and state-of-the-art: to people with insomnia to help improve their Sleep experience; and to healthcare practitioners in order to inform and enhance their practice. As a result, this chapter will not engage in a lengthy repetition of the evolving theories as to the purpose of Sleep over the years, but will describe where we are at the moment and how this can be of use to the individual with a Sleep problem and the practicing healthcare professional, restricting its range to human Sleep in health and “disease”. This chapter is subdivided into sections that will examine our current knowledge about Sleep from different perspectives. After an initial examination of the various states of consciousness, we will look at circadian rhythms, Sleep stages, current ideas about memory, how Sleep changes as we age, the influence of light on our Sleep, tiredness, how social cues impact on our Sleep, and then how physical and psychological insults can reduce the quality and quantity of our Sleep. This chapter will then conclude by pulling all these elements together to explain the complex and dynamic nature of Sleep. After reading through this chapter it is anticipated that the reader will have a good base-knowledge about the science underpinning what it is to Sleep in health and in poor health, so providing them with a good foundation on which to introduce therapeutic interventions to help improve Sleep in themselves, and for their families, friends, and clients.

  States of consciousness

  So to begin with it is worth looking at our minds and how we live life as perceived by our brains. Essentially there are three states of consciousness, which are all very different from one another; and our brains shift between these states continuously throughout our lives, every day, all the time. If we do not allow this shifting to occur, we suffer. If anyone has stayed awake for more than a couple of days and nights, then they will be acutely aware of what this feels like. Jet lag, shift work, being a new parent, there are many ways to experience these feelings, in fact everyone knows the feeling, we call it “tired”, we call it “fatigued”. This is because we need to shift our consciousness regularly, as to exactly why we need to do this still remains something of an enigma, although we are becoming increasingly aware these days that it has something very important to do with memory (to be discussed later in this chapter). The consequences of not shifting are serious, from mild discomfort to billions of lost working hours (and so money), and huge industrial accidents with major consequences to people, economies, and the environment. The big things we have all seen on the news— the Chernobyl nuclear power plant disaster, the Exxon-Valdes oil tanker spillage, the Three Mile Island nuclear core melt down, the Challenger space shuttle explosion, and so on. The smaller, subtler impact of mild to moderate tiredness and fatigue on the population is much more difficult to measure, but estimates are massive. In the US, where there have been detailed investigations conducted into the cost insomnia to society indicate direct cost estimates of fourteen billion dollars annually, rising to $100 billion for indirect costs (including work-related accidents and lost productivity), these were estimates from early in this second millennium (Sivertsen & Nordhus, 2007 ). More recently, independent research from the RAND Institute has indicated a global cost of insomnia, including both direct and indirect costs, in the region of $411 billion in the US, and $50 billion in the UK, amounting to around 2% of the GDP of these countries (Hafner et al., 2016

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  Psychology in Action

  • Karen R. Huffman, Katherine Dowdell, Catherine A. Sanderson(Authors)
  • 2017(Publication Date)
  • Wiley

    (Publisher)

  Yoo, Seung-Schik et al. Current Biology , Volume 17 , Issue 20 , R877 - R878 160 CHAPTER 5 States of Consciousness Having discussed our daily circadian cycle and the problems associated with its disruption, we now turn our attention to our cyclical patterns and stages of Sleep. We begin with an explora- tion of how scientists study Sleep. Surveys and interviews can provide general information, but for more detailed and precise data researchers in Sleep laboratories use a number of sophisti- cated instruments (Concept Organizer 5.2). Imagine that you are a participant in a Sleep experiment. When you arrive at the Sleep lab, you are assigned one of several bedrooms. The researcher hooks you up to various physiolog- ical recording devices, which will require a night or two of adaptation before the researchers can begin to monitor your typical night’s Sleep (Concept Organizer 5.2a). After this adaptation, if you’re like most Sleepers, you’ll begin the Sleep cycle with a drowsy, preSleep state followed by several distinct stages of Sleep, each progressively deeper (Concept Organizer 5.2b). Then the sequence begins to reverse. Note that we don’t necessarily go through all Sleep stages in this exact sequence (Concept Organizer 5.2c). But during the course of a night, people usually complete four to five cycles of light to deep Sleep and then back up to light Sleep. Each of these down and up cycles lasts about 90 minutes. Also note the two important divisions of Sleep shown in Concept Organizer 5.2b and 5.3c: rapid-eye-movement (REM) Sleep and non-rapid-eye-movement (NREM) Sleep (Stages 1, 2, and 3). Rapid-eye-movement (REM) Sleep The fourth stage of Sleep, marked by rapid eye movements, irregular breathing, high-frequency brain waves, paralysis of large muscles, and often dreaming. Non-rapid-eye-movement (NREM) Sleep The Sleep stages (1 through 3) during which a Sleeper does not show rapid eye movements.

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  How to Sleep Well

  The Science of Sleeping Smarter, Living Better and Being Productive

  • Neil Stanley(Author)
  • 2018(Publication Date)
  • Capstone

    (Publisher)

  The difference simply was that in captivity they had all their needs met, and so didn’t have to spend time looking for food, water, and so on. WHAT IS Sleep? 3 WHAT IS Sleep? What is that thing that Shakespeare called The death of each day’s life, sore labour’s bath, Balm of hurt minds, great nature’s second course, Chief nourisher in life’s feast. (Macbeth) Sleep is divided into two distinct states, Rapid Eye Movement (REM) Sleep and non-REM Sleep, with non-REM Sleep being further divided into three stages; N1, N2, N3, each of increasing depth. During the night you pass through the four Sleep stages: N1, N2, N3, and REM Sleep in what are known as ‘Sleep cycles’. Sleep pro-gresses cyclically from N1 through to REM, then begins again with stage N1. Each Sleep cycle lasts approximately 90 to 110 minutes in adults. The first couple of Sleep cycles have long periods of unin-terrupted deep N3, or Slow Wave Sleep (SWS), with relatively short REM periods. Later in the night the REM periods lengthen and SWS Stages Awake REM N1 N2 N3 0 1 2 3 SWS 4 5 6 7 8 Hours of Sleep SWS 4 HOW TO Sleep WELL is mostly absent. Thus, the first third of the night is predominantly SWS Sleep and the later part of the night is spent in the lighter stages, N1, N2, and REM Sleep. On the previous page is stylised representation of a night’s Sleep for an adult showing the distribu-tion of the various Sleep stages across the night. Stage N1 (3–7% of Sleep) is the lightest stage of Sleep and is the transition between wake and Sleep. It is the type of Sleep that you have at the start of the night when you feel you are drifting in and out of Sleep. When you are in stage N1 Sleep you can be woken easily, and indeed if you are awakened you will probably claim not to have been aSleep. During the transition from wake to Sleep, many people experience sudden muscle contractions or ‘jerks’; a sensation of falling or a ‘presence’, benign or otherwise, in the room.

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  Research in Occupational Stress and Well being

  • Sabine Sonnetag, Pamela L. Perrewé, Daniel C. Ganster, Sabine Sonnetag, Pamela L. Perrewé, Daniel C. Ganster(Authors)
  • 2009(Publication Date)
  • Emerald Group Publishing Limited

    (Publisher)

  FACTORS IN SOCIETY THAT INTERFERE WITH Sleep Sleep is easily interfered with through various types of activities, states, and circumstances. Stress is one of the most common factors attributed to disturbed Sleep, but also irregular work hours and irregular life patterns is an important contributor. We will focus on these factors in this review, but one should also be aware of other circumstances such as many diseases and environmental noise. Sleep and Recovery 219 Stress and Sleep One major obstacle to Sleep is stress. Here, we will focus on the role of stress in preventing recuperation through Sleep. The core problem of stress with regard to Sleep is that stress produces significant physiological activation, which is in conflict with the inherent requirement of physiological deactivation during Sleep. The Concept of Stress From a general perspective psychosocial stress refers to the ‘‘the rate of wear and tear in the organism,’’ and the biological definition of stress refers to the nonspecific response to any demand ( Selye, 1956 ) to increase the chances of survival of an individual who is facing a life-threatening situation. More specifically, stress is determined by the balance between the perceived demands from the environment and the individual’s resources to meet those demands ( Selye, 1956 ). The Cognitive Activation Theory of Stress ( Ursin & Eriksen, 2004 ) is a recent development of these ideas, focusing on the perception of the gap between the present resources and demands. Contemporary physiological stress models derive from Cannon (1914) and Selye’s (1946) pioneering work. Selye (1946) proposed a model of stress, the general adaptation syndrome (GAS), comprised of three stages: these were alarm, resistance, and exhaustion, and reflected the physiological nonspecific response to a challenge. The resistance stage of GAS has profound energy requirements, which, if persistent over time, depletes the person’s capacity and leads to exhaustion.

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  Sleep Psychiatry

  • Alexander Golbin, Howard Kravitz, Louis G. Keith, Alexander Golbin, Howard Kravitz, Louis G. Keith(Authors)
  • 2004(Publication Date)
  • Taylor & Francis

    (Publisher)

  Similarity between dream images and hallucinations suggested that if we discover the nature of dreams we will understand the physiology of hallucinations and, ultimately, the nature of psychoses. This theory was a logical and very attractive illusion and became one of the beautiful tales of the 20th century. Psychophysiological study of Sleep and dreaming was also attractive because it opened new avenues for determining mind–body interactions that are not present during wakefulness 7 . The methodology of the psychophysiological study of Sleep includes polysomnography tests and multiple rating scales. Episodes of activations in Sleep give good time points of measurement and associations between mentation and physiological parameters. A study showed that dreaming in the non-rapid eye movement (NREM) stage is possible but not frequent (8%) compared to 80% of dream reports from the REM stage. In 1967, Foulkes summarized the argument for the validity of NREM dreams 8 . It was the end of a convenient illusion about REM as a unique dream state. Weak attempts to save the REM tale of changes in semantic definition of dreams as ‘coherent and detailed descriptions of dream content’ vs. ‘vague fragmentary impressions’ in NREM did not help. In some dreams the dreamer passively accepts pictures and discontinuity between objects and events, but there are other types of mentation even in REM: (1) REM and narcoleptic vivid dreams; (2) Nightmares where the dreamer may accept some control over dream mentation, or real somatic activation appropriate to a dream might be elicited. In fact, dreaming may have NREM onset, if it occurs in Sleep-like states: meditation, daydreaming, etc. Deprivation of REM does not lead to psychosis. Paradoxically REM deprivation may lead to clinical improvement in some cases of depression, but long morning REM might increase the intensity of negative dreaming. REM and NREM states are different in their mentation.

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