Psychology: States of Consciousness PDF

CHAPTER 6 CHAPTER OUTLINE States of Consciousness THE PUZZLE OF CONSCIOUSNESS DRUGS AND ALTERED CONSCIOUSNESS Measuring States of Consciousness Levels of Consciousness: Psychodynamic and Cognitive Perspectives Drugs and the Brain Tolerance and Withdrawal Depressants Frontiers: Detecting Awaren...

CHAPTER 6 CHAPTER OUTLINE States of Consciousness THE PUZZLE OF CONSCIOUSNESS DRUGS AND ALTERED CONSCIOUSNESS Measuring States of Consciousness Levels of Consciousness: Psychodynamic and Cognitive Perspectives Drugs and the Brain Tolerance and Withdrawal Depressants Frontiers: Detecting Awareness Research Foundations: Drinking and Driving: Decision Making in Altered States The Neural Basis of Consciousness CIRCADIAN RHYTHMS: OUR DAILY BIOLOGICAL CLOCKS Keeping Time: Brain and Environment Environmental Disruptions of Circadian Rhythms Applications: Outsmarting Winter Depression, Jet Lag, and Night Shiftwork Disruptions SLEEP AND DREAMING Stages of Sleep Getting a Night’s Sleep: Brain and Environment How Much Do We Sleep? Sleep Deprivation Why Do We Sleep? Sleep Disorders The Nature of Dreams Stimulants Opiates Hallucinogens Marijuana From Genes to Culture: Determinants of Drug Effects HYPNOSIS The Scientific Study of Hypnosis Hypnotic Behaviours and Experiences Focus on Neuroscience: The Neuroscience of Meditation Theories of Hypnosis SOME FINAL THOUGHTS Our normal waking consciousness is but one special type of consciousness, whilst all about it, parted from it by the filmiest of screens, there lie potential forms of consciousness entirely different. —William James What are the issues here? What do we need to know? Where can we find the information to answer these questions? Lee Hadwin is a nurse from North Wales. But he is better known as “Klpasso,” the artist who produces pencil drawings and works of fantasy. Lee does not know how he produces such work, because he can only draw at night when he is asleep. When awake, Lee has no artistic ability at all and is dumbfounded at the pieces he produces during the night. Hadwin has been sleepwalking since he was four years old and began to draw works of art sometime in his teens. He now leaves art supplies out at night and routinely draws for 20 to 90 minutes. He awakes with a severe migraine, feeling totally exhausted. He has been offered $7500 for one of his works, and he recently placed his entire collection of 100 pieces for sale on eBay. The asking price is $1.9 million. lthough the experience of Lee Hadwin is unusual, it demonstrates the surprising complexity of our conscious experience. We all drift into and out of various states of consciousness. By state of consciousness, psychologists mean a pattern of subjective experience, a way of experiencing internal and external events. You will also encounter the phrase altered state of consciousness, which refers to variations from our normal waking state. While daydreaming or passing from wakefulness to sleep, we may experience vivid images, and our nighttime dreams can seem just as real and emotionally charged as our waking perceptions. We also experience divisions of awareness. Consider this: Why don’t you fall out of bed at night? You are not consciously aware of major postural shifts while soundly asleep, yet a part of you somehow knows where the edge of the bed is. Similarly, have you ever “spaced out” while driving, deeply A engrossed in thought? Suddenly you snap out of it, with no memory of the kilometres just driven. While you were consciously focused inward, some part of you kept track of the road and controlled your responses at the wheel. Philosopher David Chalmers (1995) notes, “Conscious experience is at once the most familiar thing in the world and the most mysterious.” As we shall see, its mysteries span a range from normal waking states to sleep and dreams, drug-induced experiences, hypnosis, and beyond. When psychology was founded in the late 1800s, its “Great Project” was to scientifically unravel some of the puzzles of consciousness (Natsoulas, 1999). This interest waned during behaviourism’s dominance in the mid-20th century, but resurgence of the cognitive and biological perspectives has sparked new research, forcing us to rethink long-standing conceptions about the mind (Figure 6.1). (a) (b) FIGURE 6.1 (a) During a Sufi religious ceremony in Istanbul, Turkey, whirling dervishes perform a spinning dance—a prayer in motion—that induces an altered state of consciousness. (b) Buddhists believe that meditation produces inner peace, facilitates insight and enlightenment, and opens a path to different dimensions of consciousness. 184 CHAPTER SIX THE PUZZLE OF CONSCIOUSNESS 1. Describe some basic characteristics of consciousness. 2. How do psychologists measure states of consciousness? What is consciousness, and how does it arise? In psychology, consciousness often is defined as our moment-to-moment awareness of ourselves and our environment. Among its characteristics, consciousness is • subjective and private. Other people cannot directly know what reality is for you, nor can you enter directly into their experiences. As the author Charles Dickens observed, “Every human creature is constituted to be that profound secret and mystery to every other.” • dynamic (ever-changing). We drift in and out of various states throughout each day. Although the stimuli of which we are aware constantly change, we typically experience consciousness as a continuously flowing “stream” of mental activity, rather than as disjointed perceptions and thoughts (James, 1890/1950). • self-reflective and central to our sense of self. The mind is aware of its own consciousness. Thus, no matter what your awareness is focused on—a lovely sunset or an itch on your back—you can reflect on the fact that “you” are the one who is conscious of it. Finally, consciousness is intimately connected with the process of selective attention, as discussed in Chapter 5. William James noted that “the mind is at every stage a theatre of simultaneous possibilities. Consciousness consists in . . . the selection of some, and the suppression of the rest by the . . . agency of Attention” (1879, p. 13). Selective attention focuses conscious awareness on some stimuli to the exclusion of others. If the mind is a theatre of mental activity, then consciousness reflects whatever is illuminated at the moment—the “bright spot on the stage”—and selective attention is the “spotlight” or mechanism behind it (Baars, 2007). Measuring States of Consciousness Scientists who study consciousness must find ways to operationally define private inner states in terms of measurable responses. The most common measure is self-report, in which people describe their inner experiences. Self-reports offer the most direct insight into a person’s subjective experiences, but they are not always verifiable. In contrast, physiological measures establish the correspondence between bodily states and mental processes. For example, EEG recordings of brain activity help to identify different stages of sleep throughout the night. Physiological measures are objective but cannot tell us what a person is experiencing subjectively. Behavioural measures also are used, including performance on special tasks, such as the rouge test (Figure 6.2). Behavioural measures are objective, but we still must infer the person’s (or chimp’s) state FIGURE 6.2 Gordon Gallup (1970) exposed four chimps to a mirror. By day three, they used it to inspect hard-to-see parts of their own bodies and began making odd faces at themselves in the mirror. To further test whether the chimps knew the mirror images were their own reflections, Gordon anaesthetized them and put a red mark on their faces. Later, with no mirror, the chimps rarely touched the red mark. But on seeing the mark when a mirror was introduced, they touched the red spot on their face almost 30 times in 30 minutes, suggesting that the chimps had some self-awareness. Using a similar test in which a red rouge mark is placed on the tip of an infant’s nose, researchers find that infants begin to recognize themselves in a mirror at around 18 months of age. States of Consciousness of mind. As you will discover in this chapter’s Focus on Neuroscience feature, progress is being made in the study of alterations in brain activity that accompany meditation. Levels of Consciousness: Psychodynamic and Cognitive Perspectives A century ago, Sigmund Freud (1900/1953) proposed that the human mind consists of three levels of awareness. The conscious mind contains thoughts, perceptions, and other mental events of which we are currently aware. Preconscious mental events are outside current awareness, but can easily be recalled under certain conditions. For instance, you may not have thought about a childhood friend for years, but when someone mentions your friend’s name, you become aware of pleasant memories. Unconscious events cannot be brought into conscious awareness under ordinary circumstances. Some unconscious content—such as unacceptable urges and desires stemming from instinctive sexual and aggressive drives, traumatic memories, and threatening emotional conflict—is kept out of conscious awareness because it would arouse anxiety, guilt, or other negative emotions. Behaviourists roundly criticized Freud’s model. After all, they sought to explain behaviour without invoking conscious mental processes, much less unconscious ones. Cognitive psychologists and many contemporary psychodynamic psychologists also take issue with specific aspects of Freud’s model, which we describe more fully in Chapter 14. As psychodynamic psychologist Drew Westen (1998, p. 333) notes, “Many aspects of Freudian theory are indeed out of date, and they should be. Freud died in 1939, and he has been slow to undertake further revisions.” On a broad level, however, research strongly supports Freud’s general premise: Nonconscious processes influence behaviour (Dimberg et al., 2000; Westen, 1998). Studies of placebo effects (see Chapter 2), split-brain patients (see Chapter 3), subliminal perception (see Chapter 5), and phenomena that you will encounter in upcoming chapters all indicate that mental processes can affect our behaviour without conscious awareness (Kirsch & Lynn, 1999). The Cognitive Viewpoint Cognitive psychologists reject the notion of an unconscious mind driven by instinctive urges and repressed conflicts. Rather, they view conscious and unconscious mental life as complementary forms of information processing (Hassin et al., 2005). As Daniel Reisberg (1997, p. 601) notes, unconscious mental activity is “not an adversary to the conscious mind. Instead, the cognitive unconscious 185 functions as a sophisticated support service, working in harmony with our conscious thoughts.” To illustrate, consider how we perform everyday tasks. Controlled versus automatic processing. Many activities, such as planning a vacation or studying, involve controlled (effortful) processing, the voluntary use of attention and conscious effort. Other activities involve automatic processing and can be performed with little or no conscious effort. Automatic processing occurs most often when we carry out routine actions or well-learned tasks. Learning to type, drive, and eat with utensils all involve controlled processing; you have to pay a lot of attention to what you are doing. With practice, performance becomes more automatic and brain areas involved in conscious thought become less active (Saling & Phillips, 2007). Through years of practice, typists, athletes, and musicians program themselves to execute highly complex skills with a minimum of conscious thought. Automatic processing, however, has a key disadvantage: It can reduce our chances of finding new ways to approach problems (Langer, 1989). Controlled processing is more flexible and open to change. Still, automatic processing offers speed and economy of effort, and in everyday life most actions may be processed this way (Bargh & Chartrand, 1999). In fact, many well-learned behaviours seem performed best when our mind is on “autopilot,” with controlled processing taking a backseat. The famous baseball player Yogi Berra captured this idea in his classic statement that “You can’t think and hit at the same time.” At tasks ranging from golf putting to video-game playing, experiments suggest that too much self-focused thinking can hurt task performance and cause people to “choke” under pressure (Beilcock & Carr, 2001). Divided attention. Automatic processing also facilitates divided attention, the ability to perform more than one activity at the same time. We can talk while we walk, type as we read, eat while watching TV, and so on. Without the capacity to divide attention, every act would require our full attention and quickly overwhelm our mental capacity. Yet divided attention has limits, and is more difficult when tasks require similar mental resources (Reisberg, 1997). For example, the shadowing experiments described in Chapter 5 indicate that we cannot attend fully to separate messages delivered simultaneously through two earphones. Although divided attention is wonderfully adaptive most of the time, it can have serious negative consequences in certain situations (Figure 6.3). For example, some studies have found that collision rates triple or quadruple when people talk on the telephone while driving; they are more likely to speed, 3. Explain Freud’s three-level model of consciousness. 4. How do cognitive psychologists view the unconscious? 5. What is automatic processing, and why is it important? 186 CHAPTER SIX Frontiers DETECTING AWARENESS It reads like the plot for a horror movie or a short story by Edgar Allen Poe: As a result of brain injury, a person is rendered immobile and unresponsive, but is still conscious and aware of the surroundings, trapped inside his or her head, unable to move or communicate. Adrian Owen and his colleagues have been investigating whether such patients exist. He studies patients who have sustained brain injuries that result in what is called a vegetative state, or a minimally conscious state. The term “vegetative state” refers to a condition in which the individual appears to be awake, but shows no evidence of awareness (Figure 6.4). These patients have a sleep-wake cycle and when their eyes are open they may show simple behaviours such random eye movements, but they do not respond to sight, sound, or touch. That is, they appear to be awake but completely unaware. If these patients are conscious, how could you tell? How do you communicate with someone who cannot move or speak? While he was at the University of Cambridge, Owen began his ground-breaking and controversial work with the study of a 26-year-old patient named Kate Bainbridge. Kate had been in a coma due to a viral infection. When the infection cleared and she came out of the coma, she entered a vegetative state. When you see a familiar face, an area of the temporal cortex called the fusiform face area (FFA) is activated. Owen tested Kate by showing her familiar faces while performing a PET scan. Amazingly, her FFA showed increased activity, just as you would expect if someone saw and recognized the faces (Menon et al., 1998). Kate was found to have significant brain function and responded well to rehabilitation; she is now in a wheelchair but otherwise active. An important next step came when Owen and his team worked with a 24-year-old man, referred to as Patient 23 (Owen et al., 2006). Patient 23 had been in a vegetative state for five years after suffering brain damage in a car accident. When you imagine playing tennis and when you imagine finding your way around your house, different parts of your brain become active. Owen and his team used this finding with Patient 23. They told him to imagine playing tennis for “yes,” and to imagine moving around his house for “no.” Owen put Patient 23 into an fMRI and asked him questions. Incredibly, he answered: “Is your father’s name Thomas?” No. “Is your father’s name Alexander?” Yes. “Do you have any brothers?” Yes. “Do you have any sisters?” No (Owen et al., 2006). It was the first time anyone had communicated with a patient in a vegetative state. Owen, now at the University of Western Ontario, is working to repeat the fMRI findings using an EEG (Cruse et al., 2012). Although an EEG does not have the precision of an fMRI and cannot measure activity deep within the brain, it is inexpensive, easy to use, and relatively portable. Developing techniques that allow answers to be detected with an continued less space between their cars and the cars in front of them and, especially during long conversations, they drive faster (Rosenbloom, 2006). Even the use of a hands-free cellphone has an impact: braking is delayed, the degree of braking is reduced, and anticipation of upcoming events is degraded (Treffner & Barrett, 2004), all of which are changes that would be expected to increase the chance of an accident. The Emotional Unconscious 6. Can nonconscious processes influence emotional responses? FIGURE 6.3 In 2003 it became illegal in Newfoundland and Labrador to use a hand-held cellphone while driving. Since then, all Canadian provinces have adopted a ban on the use of cellphones while driving, while some, such as British Columbia and Ontario, banned all hand-held devices while driving. drive on the wrong side of the road, run off the road, hit fixed objects, and overturn their cars (Redelmeier & Tibshirani, 1997; Violanti & Marshall, 1996). While engaged in a cellphone conversation, drivers leave Some modern psychodynamic views incorporate information-processing concepts from cognitive psychology but strongly emphasize that emotional and motivational processes also operate unconsciously and influence behaviour (Gillett, 1997; Westen, 1998). The results of numerous experiments have strengthened the view that unconscious processes can have an emotional and motivational flavour (LeDoux, 2000). For example, have you ever been in a bad mood or a good mood, without knowing why you were feeling that way? Perhaps, as Bargh and Chartrand (1999) propose, it is because States of Consciousness EEG would allow faster, less expensive, bedside testing of vegetative patients. For patients far from the large medical centres that have expensive fMRI equipment and the highly trained personnel to perform the scans, an EEG may be a viable option. Recently, Owen and his team reported a stunning breakthrough while working with normal healthy volunteers (Naci et al., 2013). Participants were asked to concentrate on “yes” or “no” to simple yes-or-no questions such as “Do you have brothers and sisters?” or “Are you younger than 21?” Using fMRI scans, researchers were able to identify answers with 90 percent accuracy. That is, participants could respond by concentrating on “yes” or “no,” rather than using some other mental activity as a code, and the researchers could correctly identify what the participant had been thinking 90 percent of the time. Owen and his team are beginning to use this method to attempt communication with patients diagnosed as being in a vegetative state. Owen’s work has implications for diagnosis, clinical care and rehabilitation, medical ethics, and medical/ legal decision making, but his findings and interpretation are controversial (Cyranoski, 2012). Some disagree with Owen’s conclusion that these patients are conscious; they argue that responses are not a sign of consciousness but are involuntary and reflexive. Others object to what they consider too simple a view of consciousness. Disorders of consciousness, including vegetative state, are some of the least understood of all disorders. Owen’s findings you were influenced by events in your environment of which you were not consciously aware. In one study, Chartrand and Bargh (2002) subliminally presented university students with nouns that were either strongly negative (e.g., cancer, cockroach), mildly negative (e.g., Monday, worm), mildly positive (e.g., parade, clown), or strongly positive (e.g., friends, music). Later, students rated their mood on standard psychological inventories. Although they were not consciously aware of seeing the nouns, those shown the strongly negative words displayed the saddest mood, whereas those who had seen the strongly positive words reported the happiest mood. In Chapter 10, we explore other aspects of the modern “emotional unconscious.” The Neural Basis of Consciousness Within our brains, where does consciousness arise? And if no individual brain cell is conscious (as far as we know), then how does brain activity produce consciousness? 187 FIGURE 6.4 Patients in a vegetative state appear to be awake but show no awareness of their surroundings, and do not respond to sight, sound, or touch. Might some of these patients be conscious and aware, but unable to move or respond? suggest that some of these patients may be aware of their surroundings and can communicate if the proper techniques are used. In 2010, Kate Bainbridge, the first vegetative state patient Adrian Owen tested more than a decade earlier, wrote to him, “It scares me to think of what might have happened to me if I had not had mine [PET scan]. It was like magic, it found me” (Cyranoski, 2012, p.179). Windows to the Brain Some researchers have examined the brain functioning of patients who have disorders that impair conscious perception. Two of these disorders are visual agnosia and blindsight. Visual agnosia is dramatically illustrated by the case of D.F., as reported by University of Western Ontario psychologist Melvin Goodale (2000). Due to carbon-monoxide exposure, D.F. lost consciousness and suffered brain damage. When she regained consciousness, she was unable to recognize the faces of friends and relatives, and she could not identify even simple objects by sight. She could recogize peoples’ voices and recognize objects by touch, but not sight. D.F.’s condition is called visual agnosia, which is an inability to visually recognize objects. If D.F. reaches for an object such as a coffee mug or a book, she orients her hand correctly, opens her hand to the correct width, and grasps the object with ease, even though she cannot identify what it is she was reaching for (Goodale, 2000; Young, 2003). 188 CHAPTER SIX 7. According to the modular model of mind, how does consciousness arise? Brain imaging revealed that D.F.’s primary visual cortex was largely undamaged from the carbonmonoxide exposure. Why, then, could she not consciously recognize objects and faces? The answer rests on the idea that there are multiple brain pathways for processing visual information (Goodale, 2000). One pathway carries information to support the unconscious guidance of movements, while a second pathway carries information to support brain areas that perform tasks related to perception, memory, emotion, and so on, and this pathway is accessible to conscious awareness (Gabbard & Ammar, 2008; Goodale, 2000). D.F.’s nonconscious visual pathway used to guide movement was intact, but part of the pathway that provides visual information for consicous recognition of faces and objects was damaged. People with visual agnosia are not blind; they can see and are aware of seeing, but they cannot identify objects by sight. Conversely, patients with blindsight will report that they cannot see. In special tests, however, a blindsight patient will respond to visual stimuli (Kentridge et al., 2004). For example, a blindsight patient may be blind in the right half of his or her visual field. If a stimulus such as a photograph or a line is flashed on a screen so that it appears within the patient’s blind visual field, the person will report that he or she did not see anything. When asked to point to where the stimulus was, blindsight patients will guess, but on some tasks the accuracy of their “guesses” is as high as 80 to 100 percent (Radoeva et al., 2008). That is, they have no conscious experience of seeing, but behave as though the stimulus was perceived accurately. As with visual agnosia, cases of blinsight demonstrate that visual information can be processed and influence behaviour outside of conscious awareness. Consciousness and the Modular Mind Many neuroscientists believe that there is no single place in the brain that gives rise to consciousness. Instead, they view the mind as a collection of largely separate but interacting information-processing modules that perform tasks related to sensation, perception, memory, movement, planning, problem solving, emotion, and so on. The modules process information in parallel—that is, simultaneously and largely independently. However, there also is cross-talk between them, as when the output from one module is carried by neural circuits to provide input for another module, or a module receives input from two independently functioning modules. For example, a formula recalled from memory can become input for problem-solving modules that allow you to compute answers during a math exam. According to one view, consciousness is a global workspace that represents the unified activity of multiple modules in different areas of the brain (Baars, 2007). In essence, of the many brain modules and connecting circuits that are active at any instant, a particular subset becomes joined in unified activity that is strong enough to become a conscious perception or thought (Koch, 2004). The specific modules and circuits that make up this dominant subset can vary as our brain responds to changing stimuli— sights, sounds, smells, and so on—that compete for conscious attention. In Review • Consciousness refers to our moment-tomoment awareness of ourselves and the environment. It is subjective, dynamic, self-reflective, and central to our sense of identity. Selective attention focuses conscious awareness on some stimuli to the exclusion of others. • Scientists use self-report, physiological, and behavioural measures to operationally define states of consciousness. • Freud believed that the mind has conscious, preconscious, and unconscious levels. He viewed the unconscious as a reservoir of unacceptable desires and repressed experiences. Cognitive psychologists view the unconscious as an information-processing system. • Controlled processing typically is required for learning new tasks. Automatic processing makes divided attention possible, enabling us to perform several tasks at once. Research on subliminal perception and other topics suggests that emotional and motivational processes also can operate nonconsciously and influence behaviour. • Many theorists propose that the mind consists of separate but interacting information-processing modules. Our subjective experience of “unitary” consciousness arises from the integrated output of these modules. States of Consciousness Subjectively, of course, we experience consciousness as unitary, and not as a patchwork of different modules and circuits. This is somewhat akin to listening to a choir sing. We are aware of the integrated, harmonious sound of the choir rather than the voice of each individual member. As we will explore in the rest of this chapter, many factors can influence these modules and, in so doing, alter our consciousness. CIRCADIAN RHYTHMS: OUR DAILY BIOLOGICAL CLOCKS Like other animals, humans have adapted to a world with a 24-hour day-night cycle. Every 24 hours, our body temperature, certain hormonal secretions, and other bodily functions undergo a rhythmic change that affects our mental alertness and readies our passage back and forth between states of wakefulness and sleep (Figure 6.5). These daily biological cycles are called circadian rhythms (from the Latin circa, “around,” and dia, “day”). Keeping Time: Brain and Environment Most circadian rhythms are regulated by the brain’s suprachiasmatic nuclei (SCN), which are located in the hypothalamus, as shown in Figure 6.6 (Miller et al., 1996; Albrecht, 2004). Work by Martin Ralph, (c) Change in body temperature (°C) Plasma melatonin pg/ml (b) 60 50 40 30 20 10 0 Alertness (a) Awake 0.4 0.2 0.0 –0.2 –0.4 of the University of Toronto (Ralph et al., 1990, Ralph et al., 1993) has confirmed that the SCN is indeed the brain’s clock. Ralph transplanted normal, healthy SCN neurons into the hypothalamus of animals whose own SCN had been destroyed. The transplanted SCN neurons restored circadian rhythms to the animals that had lacked a healthy SCN (Ralph et al., 1990). SCN neurons have a genetically programmed cycle of activity and inactivity, functioning like a “biological clock.” They link to the tiny pineal gland, which secretes melatonin, a hormone that has a relaxing effect on the body. SCN neurons become active during daytime and reduce the pineal gland’s secretion of melatonin, raising your body temperature and heightening alertness. At night SCN neurons are inactive, allowing melatonin levels to increase and promoting relaxation and sleepiness (Zee & Lu, 2008). Our circadian clock is biological, but environmental factors such as the day-night cycle help to keep SCN neurons on a 24-hour schedule (Lewy et al., 1998; Wever, 1989). Your eyes have neural connections to the SCN. After a night’s sleep, the light of day increases SCN activity and helps to reset your 24-hour biological clock. What would happen if you lived in the dark, or in a laboratory or an underground cave without clocks, and could not tell whether it was day or night outside? Most people drift into a longer “natural” cycle of about 24.2 to 24.8 hours, called a free-running circadian Sleep Awake Sleep High Low Noon 6 P.M. Midnight 6 A.M. Noon 6 P.M. Midnight 6 A.M. Time of Day FIGURE 6.5 Changes in our core body temperature (a), levels of melatonin in our blood (b), and degree of alertness/sleepiness (c) follow a cyclical 24-hour pattern called a circadian rhythm. Humans also have longer and shorter biological cycles, such as the 28-day female menstrual cycle and a roughly 90-minute brain activity cycle during sleep. Adapted from Monk et al., 1996. 189 8. How do the brain and environment regulate circadian rhythms? 9. What are free-running circadian rhythms? CHAPTER SIX 3.3 Morning students (“early birds”) Evening students (“night owls”) 3.2 3.1 3.0 Grades 190 2.9 2.8 2.7 Hypothalamus SCN (regulates circadian rhythms) 2.6 Pineal gland (secretes melatonin) FIGURE 6.6 The suprachiasmatic nuclei (SCN) are the brain’s master circadian clock. Neurons in the SCN have a genetically programmed cycle of activity and inactivity, but daylight and darkness help to regulate this cycle. The optic nerve links our eyes to the SCN, and SCN activity affects the pineal gland’s secretion of melatonin. In turn, melatonin influences other brain systems governing alertness and sleepiness. rhythm (Hillman et al., 1994; Shanahan et al., 1999; Wever, 1989). Amazingly, SCN neurons exhibit this longer cycle of firing even when they are surgically removed from the brain and kept alive in a dish containing nutrients (Gillette, 1986; Schibler, 2006). Because their free-running circadian rhythm is desynchronized (out of sync) with the 24-hour daynight cycle, participants in these “isolation studies” tend to go to bed and wake up later each day. They do not realize it, but within a few weeks they may be going to bed at noon and awakening at midnight. Blind children and adults whose eyes are completely insensitive to light also may experience free-running circadian rhythms (Sack & Lewy, 1997). When they try to force their sleep-wake cycle into the 24-hour world by going to bed at fixed times, blind people often experience insomnia, other sleep problems, and daytime fatigue. Early Birds and Night Owls Circadian rhythms influence our tendency to be a “morning person” or a “night person” (Emens et al., 2009). Compared to night people, morning people go to bed and rise earlier, and their body temperature, blood pressure, and alertness peak earlier in the day. Studies around the globe indicate that “morningness” is more common among older adults, whereas more night people are found among 18- to 30-year-olds (Ishihara et al., 1992). Cultures also differ in their overall tendency toward “morningness.” Carlla Smith and her colleagues (2002) used questionnaires to measure the degree of morningness among college students from six countries. They found that students from Colombia, India, and Spain—regions with warmer annual 2.5 8 A.M. classes Later classes FIGURE 6.7 In a study of 454 University of Kansas students, “night owls” struggled in their 8:00 A.M. classes, as compared with “early birds.” In later classes the two groups performed more similarly. Stated differently, early birds did slightly better in their earliest class than in later classes, whereas night owls did better in their later rather than their earliest classes. Data from Guthrie et al., 1995. Thinking critically EARLY BIRDS, CLIMATE, AND CULTURE Is the study of morningness by Carlla Smith correlational or experimental? What factors other than climate might explain why people from warmer regions display greater morningness? Think about it, and then see the Answers section at the end of the book. climates—exhibited greater morningness than students from England, the United States, and the Netherlands. In university, morning people are more likely to take very early classes than are night people and, as Figure 6.7 shows, they perform better than night people in early morning (8:00 a.m) classes. Environmental Disruptions of Circadian Rhythms Gradual and sudden environmental changes can disrupt our circadian rhythms. Seasonal affective disorder (SAD) is a cyclic tendency to become psychologically depressed during certain months of the year. Symptoms typically begin in fall or winter, which usher in shorter periods of daylight, and then lift in spring (Rosenthal & Wehr, 1987; Sohn & Lam, 2005). Many experts believe that the circadian rhythms of SAD sufferers may be particularly sensitive to light, so as sunrises occur later in winter, the daily “onset” time of their circadian clocks may States of Consciousness 50° 45° SAD Winter blues 7.2% 20.2% 6.1% 17.1% 5.0% 13.9% 3.9% 10.6% 2.8% 7.5% 40° 35° 30° 25° FIGURE 6.8 The latitude puzzle. In North America, the prevalence of winter SAD and milder depression (“winter blues”) increases at more northerly latitudes, where the hours of daylight diminish more severely in late fall and winter. SAD and “winter blues” rates of 9.2 percent and 19.1 percent, respectively, have been found in Fairbanks, Alaska (648 latitude). Yet European studies report lower winter SAD rates and a weaker SAD–latitude relation. In fact, most studies in Sweden, Norway, Finland, and Iceland (roughly 558 to 708 latitude) report winter SAD rates similar to those in the southern United States (Mersch et al., 1999). At present, the reason for this discrepancy is debated. 12 Sleep duration (hours) be pushed back to an unusual degree (Avery et al., 1997; Teicher et al., 1997). In late fall and winter, when many people must arise for work and school in darkness, SAD sufferers are still in “sleepiness” mode long after the alarm clock sounds in the morning (Figure 6.8). Jet lag is a sudden circadian disruption caused by flying across several time zones in one day. Flying east, you “lose” hours from the day; flying west, the travel day becomes longer than 24 hours. Jet lag often causes insomnia, decreased alertness, and poorer performance until the body readjusts. It is a significant concern for businesspeople, athletes, airline crews, and others who frequently travel across many time zones (Reilly, 2009). The body naturally adjusts about one hour or less per day to time zone changes. Typically, people adjust faster when flying west, presumably because lengthening the travel day is more compatible with our natural free-running circadian cycle (Revel & Eastman, 2005). The most problematic circadian disruption for society is caused by night shiftwork. Adjusting to an inverted night-day world can be difficult. Night shiftworkers often drive home in morning daylight, making it harder to reset their biological clocks (Sasseville et al., 2009). On days off, they often fall back into a day-night schedule to spend daytime with family, which disrupts their hard-earned circadian adjustments. Over time, fatigue, stress, and the likelihood of an accident increases (Folkard, 2008). Our biological clocks promote sleepiness in the early-morning hours (Akerstedt, 1988). Combined with fatigue from poor daytime sleep, this earlymorning sleepiness can be a recipe for disaster. Shift workers who go to bed in midday get little sleep 10 8 6 4 German Japanese 2 0 12 A.M. 4 A.M. 8 A.M. Noon 4 P.M. 8 P.M. 12 A.M. Bedtime FIGURE 6.9 When night workers try to go to bed in midday, they get little sleep. These data are based on 2322 German shiftworkers (purple line) and 3240 Japanese shiftworkers (green line) who recorded their bedtimes and length of sleep. From Monk et al., 1996. Job performance errors, fatal traffic accidents, and engineering and industrial disasters peak between midnight and 6:00 a.m (Akerstedt et al., 2001). On-the-job sleepiness is a major concern among nighttime long-distance truck and bus drivers, locomotive engineers, airline crews, and medical doctors and nurses (Quera-Salva et al., 1997). Some people adjust to night work, but others never do. They become fatigued, stressed, and more accident-prone on and off the job. You can see in Figure 6.9 that, overall, nightworkers who try to go to bed during the middle of the day get frightfully little sleep. When work shifts change, it is easier to extend the “waking day” than to compress it. 10. Explain how SAD, jet lag, and night shiftwork involve circadian disruptions. 191 192 CHAPTER SIX Applications OUTSMARTING WINTER DEPRESSION, JET LAG, AND NIGHT SHIFTWORK DISRUPTIONS Circadian research has provided important insight into the nature of consciousness. It also has led to several treatments for circadian disruptions affecting millions of people. Controlling Exposure to Light Treating SAD Many experts believe that phototherapy, which involves properly timed exposure to bright artificial light, is the best treatment for SAD (Strong et al., 2009). Several hours of daily phototherapy can shift circadian rhythms by as much as two or three hours per day (Shanahan et al., 1999). Timo Partonen (1994) found that, during Finland’s short winter days, phototherapy for just one hour a day over two weeks significantly reduced SAD sufferers’ depression. In dawn simulation, artificial light gradually intensifies to normal light levels over the course of one to two hours in the early morning, which helps to reset the circadian clock to an earlier time. The fact that phototherapy effectively treats SAD is the strongest evidence that SAD is triggered by winter’s lack of sunlight, rather than its colder temperatures (Figure 6.10). up” to local time. (Think of morning light as “jump-starting” your circadian clock at a time when you would be asleep back at home.) Flying west, your body clock moves “ahead” of local time, so to reduce jet lag you want to delay your circadian cycles. Avoiding bright light in the morning and exposing yourself to light in the afternoon or early evening will do this. These are general rules, but the specific timing and length of exposure to light depend on the number of time zones crossed (Waterhouse & Reilly, 2009). For jet travellers, Reducing Jet Lag When you fly east across time zones, your body’s internal clock “falls behind” the time at your destination. Exposure to outdoor light in the morning—and avoiding light late in the day—moves the circadian clock forward and helps it “catch FIGURE 6.10 For many people, daily exposure to bright fluorescent lights can reduce the depression accompanying seasonal affective disorder. continued A forward rotating work schedule that takes advantage of this is called rotating shiftwork. One might wonder whether it takes large changes in our schedules to disrupt our circadian rhythms, or whether smaller changes can also have an impact on our behaviour and our well-being. Stanley Coren, of the University of British Columbia, analyzed reports of all accidental deaths in the United States over a three-year period. Interestingly, he found that the springtime shift to Daylight Savings Time, when we all lose an hour’s sleep and have to make a small adjustment to our circadian rhythms, produced a short-lived increase in the likelihood of accidental death (Coren, 1996b). SAD, jet lag, night shiftwork, and even changing to Daylight Savings Time all disrupt our circadian In Review • Circadian rhythms are 24-hour biological cycles that help to regulate many bodily processes. The suprachiasmatic nuclei (SCN) are the brain’s master circadian clock. Environmental factors, such as the day-night cycle, help to reset our daily clocks to a 24-hour schedule. • Circadian rhythms influence whether we are a “morning person” or a “night person.” • Seasonal affective disorder (SAD), jet lag, and night shiftwork involve environmental disruptions of circadian rhythms. Treatments for circadian disruptions include controlling exposure to light, oral melatonin, and regulating daily activity schedules. States of Consciousness spending time outside (even on cloudy days) is the easiest way to get the needed exposure to light. Adjusting to Nightwork Many night employees work indoors, where the artificial light is too weak to shift their circadian rhythms toward a night-day schedule. Circadian adjustment can be increased by having very bright indoor lighting at the workplace, keeping bedrooms dark and quiet to foster daytime sleep, and maintaining a schedule of daytime sleep even during days off (Boulos, 1998). Melatonin Treatment: Uses and Cautions Melatonin levels in the brain can be manipulated directly by oral doses. Depending on when it is taken, oral melatonin can shift some circadian cycles forward or backward by as much as 30 to 60 minutes per day of use (Zhdanova & Wurtman, 1997). Melatonin treatment has been used to alleviate SAD, decrease jet lag, and help employees adapt to night shiftwork (Arendt, 2009; Lewy et al., 2006). The availability of melatonin varies in different jurisdictions. Melatonin is sold over-the-counter as a dietary supplement in Canada and the United States. It is worth noting that substances sold as dietary supplements are not subject to the same regulations about purity, exact dosage, safety, and efficacy as are drugs. Tablet doses are often 3 milligrams, producing melatonin levels in the blood that are more than 10 times the normal concentration (Sack et al., 1997). In contrast, doses of 0.1 to 0.5 milligrams used in research produce blood rhythms and our behaviour. As explored in the Applications feature, techniques are available to help us normalize our circadian rhythms. SLEEP AND DREAMING Our circadian rhythms do not regulate sleep directly. Rather, by decreasing nighttime alertness, they promote a readiness for sleep and help to determine the optimal period when we can sleep most soundly (Sack et al., 1998). We spend approximately a third of our lives asleep, and it is easy to understand why this state of altered consciousness has mystified humans for ages. Each night we seem to relinquish conscious control of our thoughts and actions, enter a world of dreams, toss about and possibly mutter or talk, but remember little of it upon awakening. Yet sleep is a behaviour that, like others, can be studied scientifically at biological, psychological, and environmental levels. 193 concentrations more typical of normal levels and are sufficient to produce circadian shifts. Taking melatonin at the wrong time can backfire and make circadian adjustments more difficult. Experts are also concerned that millions of people are using melatonin tablets as a nightly sleeping aid, even though possible side effects of long-term use have not been adequately studied, and the evidence is that the hypnotic, or sleep-promoting, effects of melatonin among healthy adults are weak and often not replicable (Arendt, 2005; Sack et al., 1998; Zhdanova & Wurtman, 1997). Regulating Activity Schedules Properly timed physical exercise can help to shift the circadian clock (Mistlberger et al., 2000). For example, compared to merely staying up later than normal, exercising when you normally go to bed may push back your circadian clock, as you would want to do when flying west (Baehr, 2001). To reduce jet lag, you can also begin synchronizing your biological clock to the new time zone in advance. To do so, adjust your sleep and eating schedules by one to two hours per day, starting several days before you leave (Eastman et al., 2005). Schedule management also applies to night shiftwork. For workers on eight-hour rotating shifts, circadian disruptions can be reduced by a forward-rotating shift schedule—moving from day, to evening, to night shifts—rather than a schedule that rotates backward from day, to night, to evening shifts (Driscoll et al., 2007). Such forward-rotating shiftwork takes advantage of our free-running circadian rhythms. When work shifts change, it is easier to extend the waking day than to compress it. Stages of Sleep Just as waking consciousness involves different states of alertness and awareness, so does sleep. Approximately every 90 minutes while asleep, we cycle through different stages in which our brain activity and other physiological responses change in a generally predictable way (Dement, 2005; Kleitman, 1963). As Figure 6.11 shows, sleep research often is carried out in specially equipped laboratories in which sleepers’ physiological responses are recorded. EEG recordings of your brain’s electrical activity show a pattern of beta waves when you are awake and alert. Beta waves have a high frequency (of about 15 to 30 cycles per second, or cps) but a low “amplitude” or height (Figure 6.12). As you close your eyes, feeling relaxed and drowsy, your brain waves slow down and alpha waves occur at about 8 to 12 cycles per second. 11. How is exposure to light used to treat circadian disruptions? 194 CHAPTER SIX 1 2 3 1 EEG (brain waves) 4 2 Right eye movements 3 Left eye movements 4 Muscle tension FIGURE 6.11 In a modern sleep laboratory, people sleep while their physiological responses are monitored. Electrodes attached to the scalp area record the person’s EEG brain-wave patterns. Electrodes attached beside the eyes record eye movements during sleep. Muscle tension is recorded, and a neutral electrode is attached to the ear. 12. What brain-wave patterns distinguish the first four stages of sleep? Stage 1 through Stage 4 As sleep begins, your brain-wave pattern becomes more irregular, and slower theta waves (3.5 to 7.5 cycles per second) increase. You are now in stage 1, a form of light sleep from which you can easily be awakened. You will probably spend just a few minutes (or less) in stage 1, during which time some people experience images and sudden body jerks. As sleep becomes deeper, sleep spindles—periodic one- to two-second bursts of rapid brain-wave activity (12 to 15 cycles per second)—begin to appear. Sleep spindles indicate that you are now in stage 2 (Figure 6.12). Your muscles are more relaxed, your breathing and heart rate are slower, and you are harder to awaken. Sleep deepens as you move into stage 3, marked by the regular appearance of very slow (0.5 to 2 cycles per second) and large delta waves. As time passes, they occur more often, and when delta waves dominate the EEG pattern, you have reached stage 4. Together, stage 3 and stage 4 are often referred to as slow-wave sleep. Your body is relaxed, activity in various parts of your brain has decreased, and you are hard to awaken. After 20 to 30 minutes of stage 4 sleep, your EEG pattern changes as you go “back through” stages 3 and 2, spending a little time in each. Overall, within 60 to 90 minutes of going to sleep, you will have completed a cycle of stages 1-23-4-3-2. At this point, a remarkably different sleep stage ensues. REM Sleep In 1953, sleep researchers Eugene Aserinsky and Nathaniel Kleitman of the University of Chicago Beta waves Awake/alert Alpha waves 1 sec 50 µV Relaxed/drowsy Theta waves Stage 1 Sleep spindle Stage 2 Delta waves Stage 3 Delta waves Stage 4 REM sleep FIGURE 6.12 Changing patterns of brain-wave activity help to define the various stages of sleep. Note that brain waves become slower and larger as sleep deepens and that the general pattern of REM sleep is similar to that of stage 1. Adapted from Dement, 1978; Hauri, 1982. struck scientific gold when they identified a sleep stage unlike the rest. Every half minute or so, bursts of muscular activity caused the sleepers’ eyeballs to vigorously move back and forth beneath their closed eyelids. Because of these rapid eye movements (REMs), this stage was called REM sleep. When Aserinsky and Kleitman awakened sleepers States of Consciousness and participating in a series of real, if bizarre, events. When subjects are awakened from non-REM sleep, they often will report some type of mental activity (Foulkes, 1985). The non-REM dream is shorter than a REM dream (Stickgold et al., 1994). The nonREM dream is also less storylike, lacking the vivid sensory and motor experiences of a REM dream. The non-REM dream is often fixed and unmoving, resembling a tableau more than a story with a plot. Apart from non-REM dreams, mental activity that occurs during non-REM sleep also may resemble daytime thoughts, although in comparison to waking thoughts they are simple and jumbled. Indeed, some of the mental activity that occurs during non-REM sleep has even been referred to as sleep thoughts because of the closer resemblance to daytime thinking than to REM dreams (Foulkes, 1985). Each cycle through the sleep stages takes about 90 minutes. Figure 6.13 shows that, as the hours pass, stage 4 and stage 3 drop out and REM periods become longer. from REM periods, they discovered that a dream was almost always reported. Even people who swore they “never had dreams” recalled them when awakened during REM. At last, science had a window through which to examine dreaming more closely. Wait for a REM period, awaken the sleeper, and catch a dream. During REM sleep, physiological arousal may increase to daytime levels. Heart rate quickens, breathing becomes more rapid and irregular, and brain-wave activity resembles that of active wakefulness. Men have penile erections and women experience vaginal lubrication. Because most dreams do not have sexual content, this REM-induced genital arousal is not a response to sexual imagery. The brain also sends signals, making it more difficult for voluntary muscles to contract. As a result, muscles in the arms, legs, and torso lose tone and become relaxed. These muscles may twitch, but in effect you are “paralyzed” and unable to move. This state is called REM sleep paralysis, and because of it, REM sleep is sometimes called paradoxical sleep: Your body is highly aroused, and yet it looks like you are sleeping peacefully because you move so little. REM sleep is often thought to be the only sleep stage in which we dream or even experience mental activity, but that is not correct. We also experience mental activity during non-REM sleep. REM dreams have their well-known storylike quality, with vivid sensory and motor elements and the perception of reality. When you are in a REM dream, you have the experience of sensing people, objects, and places, of moving and behaving, and of witnessing Relaxed/ drowsy Getting a Night’s Sleep: Brain and Environment The brain steers our nightly passage into and through sleep, but it does not contain a single “sleep centre.” Different aspects of the sleep cycle, such as falling asleep, REM sleep, and slow-wave sleep, are controlled by different brain mechanisms. Moreover, falling asleep is not just a matter of “turning off ” the brain systems that regulate wakefulness. Separate systems “turn on” and actively promote sleep. REM 1 REM 2 REM 3 REM 4 REM 5 REM 1 REM 2 REM 3 REM 4 REM 5 Stage 1 Stage 2 Stage 3 Stage 4 Dreams Eye movements 1 2 3 4 5 6 7 Hours of sleep FIGURE 6.13 This graph shows a record of a typical night’s sleep. People typically average four or five REM periods during the night. As the night wears on, we spend less time in the deepest stages of sleep and more time in REM sleep. 195 13. Describe some major characteristics of REM sleep. 196 CHAPTER SIX 14. What brain areas help to regulate sleep onset and REM sleep? is in REM. But as we age, three important changes occur: Areas at the base of the forebrain (called the basal forebrain) and within the brain stem are particularly important in regulating our falling asleep (McGinty & Sterman, 1968; Szymusiak, 1995). A different brain stem area—where the reticular formation passes through the pons—plays a key role in initiating REM sleep (Hobson et al., 1998). This region contains “REM-sleep On” neurons that periodically activate other brain systems, each of which controls a different aspect of REM sleep, such as eye movements, muscular paralysis, and genital arousal. Sleep is biologically regulated, but the environment plays a role as well. The change of seasons affects sleep; in fall and winter, most people sleep about 15 to 60 minutes longer per night (Campbell, 1993). Shiftwork, jet lag, stress at work and school, and nighttime noise can decrease sleep quality (Saremi et al., 2008). • We sleep less. On average, 15- to 24-year-olds average 8.5 hours of sleep per day, and elderly adults average just under six hours. • REM sleep decreases dramatically during infancy and early childhood, but remains relatively stable thereafter. • Time spent in stages 3 and 4 declines. By late adulthood, we get relatively little slow-wave sleep. A parent, caregiver, relative, or friend has told you that you need eight hours of sleep a night. We have all heard this, but is it true? Many researchers and health care professionals do suggest that we need about eight hours of uninterrupted sleep a night. Research has found, however, that if we follow our own natural rhythms, with no clocks and scheduled routines, we sleep between 10 and 12 hours a night (Coren, 1996). How much sleep a person needs is influenced by genetic factors, work schedules, stress, age, lifestyle, and general health, among other factors (de Castro, 2002; Vincent et al., 2009; Williams, 2001). Although most of us may need eight to ten hours of sleep a night, some famous individuals have functioned well on surprisingly little sleep: British prime ministers How Much Do We Sleep? 24 Waking 16 14 Total hours of daily sleep 15. How do sleep patterns change as we age? The question seems simple enough, as does the answer for many of us: not enough! In reality, the issue is complex. Figure 6.14 reveals that there are substantial differences in how much people sleep at various ages. Newborn infants average 16 hours of sleep a day, and almost half of their sleep time 12 50% 40% 10 25–30% REM sleep 25% 20% 19% 8 6 Percentage of total sleep spent in REM 19% 20% 22% Non-REM sleep 19% 20–23% 4 2 0 1–15 days 3–5 mos 6–23 mos Infancy 2–3 yrs 3–5 yrs 5–9 yrs Childhood 10–13 14–18 19–30 31–45 yrs yrs yrs yrs Adolescence 50 yrs 90 yrs Adulthood Old age FIGURE 6.14 The percentage of sleep time in REM and non-REM sleep changes with age. Average daily sleep time decreases over the lifespan, and most of the decrease in non-REM sleep is due to decreasing delta sleep (stages 3 and 4). REM sleep time decreases throughout childhood and then is relatively stable through adulthood. Adapted from H.P. Roffwarg, J.N. Muzio & W.C. Dement, “Ontongenic Development of Human Dream-Sleep Cycle,” Science, 152, 604, Fig 1. Copyright © 1966, AAAS. Reprinted with permission from AAAS. States of Consciousness Winston Churchill and Margaret Thatcher, U.S. president John F. Kennedy, and Napoleon Bonaparte all reportedly slept between 3 and 5.5 hours a night (Sharkey, 1993), and Leonardo DaVinci is reported to have slept as little as two hours a day. Whether we need eight or ten hours of sleep a night, how much time do we actually spend sleeping? Canadians aged 15 and over sleep an average of eight hours and 18 minutes a night (Statistics Canada, 2010). This is an increase of almost 15 minutes of sleep per night from the late 1990s. These figures, however, conceal large individual differences. Although we average more than eight hours of sleep a night, 15 percent of Canadians 15 years old and older sleep less than 6.5 hours a night (Williams, 2001). Sleep Deprivation Sleep deprivation is a way of life for many university students, and they are not alone. Almost half of us sacrifice some sleep to accomplish more work (National Sleep Foundation, 2000; Williams, 2001). Millions more lose sleep because of disorders. Psychologists study sleep deprivation for its practical significance and to gain insight into why we need to sleep. June Pilcher and Allen Huffcutt (1996) of Bradley University meta-analyzed 19 sleep deprivation studies in which participants underwent either short-term total sleep deprivation (up to 45 hours without sleep), long-term total sleep deprivation (more than 45 hours without sleep), or partial deprivation (being allowed to sleep no more than five hours per night for one or more consecutive nights). Participants’ self-reported mood (e.g., irritability, disorientation), responses on mental tasks (e.g., ability to concentrate, logical reasoning, word memory), and physical tasks (e.g., manual dexterity, treadmill-walking) were measured. What would you predict? Would all types of deprivation affect behaviour, and which behaviours would be affected the most? Combining across the different types of deprivation and behaviour, the results were remarkable: The “average” sleep-deprived person functioned only as well as someone in the bottom 9 percent of nondeprived participants. All three types of sleep deprivation had a negative impact on functioning. Mood suffered most, followed by cognitive and then physical performance, although all three behaviours showed significant impairment from sleep loss. What about students who pull all-nighters or drastically cut back their sleep, and claim they still perform as well as ever? Pilcher and Walters (1997) found that university students deprived of one night’s sleep performed more poorly on a criticalthinking task than students allowed to sleep. Yet sleep-deprived students incorrectly perceived that they performed better and felt that they concentrated and tried harder. The authors concluded that the students underestimated the negative effects of sleep loss on performance. Most total sleep deprivation studies with humans last less than five days, but 17-year-old Randy Gardner set a world record by staying awake for 11 days as his project for a 1964 high school science fair in San Diego. Grateful sleep researchers received permission to study him (Gulevich, Dement, & Johnson, 1966). At times during the first few days, Randy became irritable, forgetful, nauseous, and intensely tired. By day five, he had periods of disorientation and distorted thinking. In the last four days, he developed finger tremors and slurred speech. Still, in his final day without sleep, he beat sleep researcher William Dement 100 consecutive times at a pinball-type game. When