states of consciousness n.
Skip this Video
Loading SlideShow in 5 Seconds..
States of Consciousness PowerPoint Presentation
Download Presentation
States of Consciousness

States of Consciousness

182 Vues Download Presentation
Télécharger la présentation

States of Consciousness

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. States of Consciousness Psychology 12

  2. Sleep Journal Researchers are still exploring the reason for sleep and dreaming. Consider what would be lost and gained if the need for sleep were eliminated. Over the next five days you will be keeping a sleep journal

  3. What is Consciousness? • Consciousness: an organism’s subjective awareness of internal and external events in its environment • Attention: internal processes that set priorities for mental functioning

  4. Awareness • Levels of awareness: • HIGH: Controlled processes that require attention (and interfere with other functions-studying, reading…) • MIDDLE: Automatic processes requiring minimal attention (such as riding your bike) • LOWEST: Minimal or no awareness of the environment

  5. Sleep • Sleep is a behavior AND an altered state of consciousness • We spend about a third of our lives in sleep.

  6. Facts about Sleep • Most adults need seven or eight hours' sleep a night • Famous figures like, Margaret Thatcher, Napoleon and Florence Nightingale only needed four • A cat sleeps for an average of 12 hours a day • Most of our dreams occur during rapid-eye movement (REM) sleep. We have around three to five REM episodes a night • Narcolepsy is a medical disorder that impacts 1 in approximately 2,000 people in the USA--narcolepsy a condition that causes them repeatedly to fall asleep in the middle of a meal, at the wheel of a car or in mid-conversation • An adult sleeping for eight hours will burn approximately 50 calories • A giraffe sleeps for an average of 1.9 hours a day • Almost two thirds of the population claim they do not get enough sleep

  7. Are You Sleep Deprived? • Task: • Set up a small mirror next star and see if you can copy the star using your non-dominant hand while watching your hand in the mirror…the task is difficult, and sleep deprived people typically make more mistakes/errors than non-sleep deprived.

  8. In your Dreams: The Mysteries of Sleep Why do we sleep? • More than 80 years after the world's first sleep laboratory opened in Los Angeles… • In spite of intensive investigations of the sleeping brain, we still do not know the answer. • Sleeping and dreaming remain among the greatest mysteries of the human organism essential to life, yet inexplicable and frustratingly unproductive.

  9. In your Dreams: The Mysteries of Sleep Why do we sleep? • While the exact function of sleep is unknown, but according to the evolutionary theory, sleep evolved to conserve energy and protect us from predators. • According to the repair/restoration theory, sleep is thought to be necessary for restorative value, both physically and psychologically.

  10. In your Dreams: The Mysteries of Sleep Why do we sleep? • Need for sleep varies among individuals, but ranges from 20 hours for infants to 6 hours for adults in their 70s

  11. In your Dreams: The Mysteries of Sleep Loss of Sleep… •  suppressed immune system • impaired creativity and concentration • slowed performance and misperceptions on monotonous tasks.

  12. In your Dreams: The Mysteries of Sleep Benefits of Sleep… • restoration of energy • repairing of brain and body tissue • release of growth hormones

  13. What is the nature of sleep? • Most people think of sleep as a state of unconsciousness, punctuated by brief periods of dreaming. Sleep is actually a state of altered consciousness, characterized by certain patterns of brain activity and inactivity.

  14. Stages of Sleep • Each night, we go through four to five cycles of distinct sleep stages. And each stage has its own rhythm and corresponding changes in brain activity and behaviour.

  15. Stages of Sleep • A sleeper progresses through Stages 1 through 4, then climbs back from Stage 4 to Stage 1 or 2, then experiences REM sleep.

  16. Stages of Sleep •  Forty to 50 percent of sleep takes place in Stage 2, which dominates the transition phase after the first two-three sleep cycles.

  17. Stages of Sleep • The average person progresses through the stages of sleep 4 to 6 times per night.

  18. Brain Waves EEG (Electroencephalograph-electro-en-cef-lo-graph) An  instrument for measuring and recording the electric  activity of the brain

  19. Stages of Sleep • Stages of sleep: Quiet Sleep and Active Sleep

  20. Stages of Sleep •  Stage 0: A person is relaxed with eyes closed a. EEG (Electroencephalograph-electro-en-cef-lo-graph: an instrument for measuring and recording the electric  activity of the brain) shows alpha waves b. This period of falling asleep is also called the hypnagogic state. (hip-na-gog-ic) c. The "waking" period between being asleep and wakefulness is called the hypnopompic state. (hip-no-pom-pic)

  21. Stages of Sleep: Early Stages of Sleep: • As you begin to fall asleep, your body temperature decreases, your pulse rate drops, and your breathing becomes slow and even. • Gradually your eyes close and your brain briefly emits alpha waves which are associated with absence of concentrated thought and with relaxation. • Your body may twitch and your eyes roll, and brief visual images flash across your mind (although your eyelids are shut).

  22. EEG Activity During Sleep • Stage 1: Light Sleep – Alpha Waves • Stage 2: Eye movements & brain waves slow; sleep spindles

  23. Stages of Sleep: Quiet Sleep-Stage 1 • and is characterized by sensory images and slow rolling eye movements and recognized by the appearance of theta waves on an EEG. Gradually your eyes close and your brain briefly emits alpha waves which are associated with absence of concentrated thought and with relaxation. • Your body may twitch and your eyes roll, and brief visual images flash across your mind (although your eyelids are shut)

  24. Stages of Sleep: Early Stages In Stage I: • This stage is characterized by sensory images and slow rolling eye movements and recognized by the appearance of theta waves on an EEG-- lower in amplitude and frequency than alpha waves. • Your pulse slows a bit more and your muscles relax, • Breathing becomes uneven and your brain waves grow irregular. If you were awakened during this stage, you would report that you were “just drifting.” • Lasts from 30 seconds to about 10 mins.

  25. Stages of Sleep: Early Stages • In Stage II • Brain waves shift from low-frequency waves to high frequency waves—a pattern that indicates you have entered Stage II sleep. • Your eyes roll slowly from side to side.

  26. EEG Activity During Sleep • Stage 3: very slow waves - delta waves appear • Stage 4: almost all delta waves • Very hard to wake during this stage

  27. Stages of Sleep: Early Stages • In Stage III • Some 30 minutes later, you drift down into a deeper level of Stage III sleep, and larger-amplitude delta waves begin to sweep your brain every second or so.

  28. Stages of Sleep: Later Stages • Stage IV • Deepest sleep of all, and it is often difficult to wake at this stage. • Large, regular Delta waves occurring more than 50% of the time indicate you are in a state of deep sleep. • If you are awakened by a loud noise, you may feel disorientated. • Talking out loud, sleepwalking, and bed-wetting—all of which may occur at this stage—leave no trace on the memory.

  29. Stages of Sleep: Later Stages • Stage IV • Deep sleep is important to your physical and psychological well-being • On average a person spends 75% of sleep time in Stages I—IV.

  30. EEG Activity During Sleep • REM stage: rapid, irregular and shallow breathing, eyes jerk rapidly, both wake and sleep waves (sawtooth pattern)

  31. Stages of Sleep--REM • Once in Stage IV, something curious happens, while your muscles are even more relaxed than before, your eyes begin to move rapidly. • This is called REM sleep (Rapid Eye Movement) • Your pulse rate becomes irregular and the levels of adrenal and sexual hormones in your blood rise—as if you were in the middle of an intensely emotional and physically demanding activity. • Often your face or fingers twitch and the large muscles in your arms and legs are paralyzed. • Your brain shows waves that closely resemble those of a person fully awake. For this reason, REM sleep is called active sleep.

  32. Stages of Sleep--REM • Stages I-IV are called NREM (non-REM) or quiet sleep. • It is during REM sleep that almost all dreaming normally takes place. • REM sleep lasts about 15-45 minutes after which you retrace the descent to State IV. • You go through this cycle every 90 minutes. Each time the length of Stage IV sleep decreases and REM sleep increases, until you eventually wake up.

  33. Stages of Sleep--REM • REM sleep is also often referred to as “paradoxical sleep”—your brain and body are giving signs of active arousal, yet your musculature is deeply relaxed and unresponsive (paralysis)…contradictory responses • How would paradoxical sleep or REM sleep serve an important adaptive function? Think about the problems and dangers that would ensue if we were to “act out” our dreams while sleeping!

  34. Stages of Sleep--REM • At no point does your brain become totally inactive • REM sleep seems to serve psychological functions such as building efficient learning and memory processes.

  35. Stages of Sleep--REM • The Sleep Cycle in Cats: • During NREM sleep , cats often sleep in an upright position. With the onset of REM sleep, cats normally lie down. • Can you explain why? • During REM sleep large muscles are temporarily paralyzed, which causes the cat to lose motor control and lie down.

  36. The Mysteries of Sleep • We spend one-thirdof our lives asleep. Imagine the possibilities if we could do without it. It would be the equivalent of adding 25 or 30 years to the average life-span an enormous gain, at the expense of nothing more than the loss of slumber.

  37. A World without Sleep • The modern 24-hour society, with its round-the-clock provision of services, has radically changed our sleep habits. • Instead of our biological clocks, the sleep of modern workers is regulated by alarm clocks, electric light and artificial stimulants. • Power napping is an essential tool for top executives, especially in Japan, where inemuri, as it's called, is widely practiced and accepted as a sign of hard work. The powerful, like the powerless, doze when they can. • Regular adequate sleep six to eight hours, in a comfy bed has become a luxury for many, something of which they can only dream.

  38. A World without Sleep • Some Japanese people suffer so much from work-related stress that they can't get to sleep even at home; instead, they spend up to $75 to attend a concert that is aimed specifically at sending them to sleep.

  39. Sleeplessness & Disasters • Exxon Valdez disaster in Alaska. When the tanker ran aground on 24 March 1989 and discharged 260,000 barrels of crude oil into the sea, it triggered one of the worst ecological disasters in history, which cost an estimated $2bn to clear up. The official inquiry by the National Transportation Safety Board concluded that overtiredness of the crew was a key cause.

  40. Sleeplessness & Disasters • Lack of sleep has similarly been blamed for the Chernobyl nuclear reactor disaster in what is now Ukraine • Three Mile Island nuclear reactor breakdown in the US • the Challenger space shuttle accident that claimed the lives of its seven astronauts. • The ferry accident on the Queen of the North (the Inside Passage Ferry disaster ), which took two lives.

  41. Sleeplessness & Disasters • At a more mundane but no less important level, tiredness is known to be a key cause of car accidents. • Scientific films made of subjects driving a simulator show the terrifying consequences of sleep deprivation. As their blinking speeds up and their eyes start to close, the vehicles they are nominally in charge of slew across the motorways, ending up, in one case, in the middle of a field.

  42. Sleeplessness & Disasters • Even these virtual motorway accidents are not as disturbing as the story of Michael Corke, a music teacher in Chicago, who died of sleeplessness in 1993. A grainy amateur video shows him at his last school concert, walking unsteadily to the conductor's podium and raising his baton, as if he were 90 years old. At that point, he had gone two months without sleep. • Soon after, he was admitted to the University of Chicago hospital. Doctors initially diagnosed multiple sclerosis. Doctors administered sedatives in a dose sufficient to induce coma in any normal human being, but Corke was unaffected. He was finally diagnosed with the rare genetic disorder of fatal familial insomnia, for which there is no treatment and no cure. He died, aged 42, after six months without sleep. The condition has so far been identified in just 25 families worldwide

  43. Sleep Deprivation • Prolonged sleeplessness, however, is crippling. Anyone who has gone for two nights without sleep will know what this means as the siren call of slumber beckons irresistibly. • Peter Tripp, a New York disc jockey, was among the first to discover its cost and he did so in public. He took part in a "wakeathon" in January 1959 to raise funds for polio research, during which he went 201 hours without sleep while continuing to broadcast from a glass booth in Times Square. • As the hours passed he became aggressive, started hallucinating and began to suspect his support group of a conspiracy against him. Yet he managed to broadcast for three hours a day throughout, though not without the help of (unidentified) stimulants. • He survived the experiment, and his symptoms of irritation and paranoia became recognized as classically linked to extreme sleep deprivation.

  44. Sleep Deprivation Losing Sleep—Exploring Psychology • In 1959 New York disk jockey Peter Tripp stayed awake for 200 hours it raise money for charity… • After about 50 hours, he started having mild hallucinations, seeing cobwebs in his shoes when there were none there and thinking that specks of dirt were bugs • By 100 hours, he became delirious and saw a doctor’s tweed suit as a tangle of furry worms; at 120 he needed a stimulant to keep him awake. • After 150 hours, he was disorientated, not knowing who or where he was, and he became paranoid—he backed against a wall, letting no one pass behind him • By 200 hours, his hallucinations had taken a sinister turn, and he thought a doctor trying to examine him was an undertaker come to bury him.

  45. Sleep Deprivation • Five years later, Randy Gardner broke the record with a stint of 11 days awake in January 1964. • He also experienced hallucinations and became increasingly grumpy with those around him, though he reportedly did without the stimulants. Instead, his friends took him on walks at night and forced him to do push-ups when he showed signs of drowsiness. • On completion of his feat, when asked at a press conference how he had done it, he replied: "It's just mind over matter." Then he curled up in bed and slept for 15 hours. • Gardner's record was authenticated by a sleep researcher and professor of psychiatry at the Stanford School of Medicine, on the basis of direct observations and electroencephalogram (EEG) recordings of Gardner's brain.

  46. Sleep Disorders • While sleep is essential to life, most of us feel we do not get enough of it. • We are a nation of insomniacs, with two-thirds of the population complaining they cannot sleep. • Insomnia is so common that doctors say the preoccupation with it is now itself a medical problem. The greatest enemy of sleep is worry about not getting enough of it. • Most people who lose sleep will be able to recover it the next night, and will be able to cope in the meantime.

  47. Sleep Disorders: When Sleep Becomes a Problem • Are you one of those lucky people who takes sleep for granted? If so you may be surprised to discover the following facts: • An estimated two-thirds of adults suffer from sleep problems and about 25 percent of children under age 5 have a sleep disturbance • One in five adults is so sleepy during the day that sleepiness interferes with their daily activities. Each year [Americans] spend more than $98 million on over-the-counter sleep aids and another $50 million on coffee to keep them awake during the day. • Twenty percent of all automobile drivers have fallen asleep for a few seconds (microsleep) at the wheel

  48. Sleep Disorders: Dyssomnia & Parasomnia • Psychologists divide sleep disorders into two major diagnostic categories: • 1) Dyssomnias: involve problems in the amount, timing, and quality of sleep • 2) Parasomnia: which include abnormal disturbances occurring during sleep

  49. Sleep Disorders: Dyssomnia • Insomnia: The term literally means “lack of sleep.” People with insomnia have persistent difficulty falling asleep or staying asleep, or they wake up too early. As much as 10% of the population genuinely suffers from insomnia, and nearly everyone occasionally experiences unwanted sleeplessness. • A telltale complaint of insomnia is that the person feels poorly rested the next day. Most people with serious insomnia have other medical or psychological disorders as well, such as alcohol and other drug abuse, anxiety disorders, and depression • Unfortunately, the most popular treatment for insomnia is drugs—either over the counter pills or prescription tranquillizers and barbiturates (which decrease Stage 4 and REM sleep therefore affect the quality of sleep)

  50. Sleep Disorders: Dyssomnia • Sleep Apnea: (Apnea literally means “no breathing”) Repeated interruption of breathing during sleep because air passages to the lungs are physically blocked or the brain stops activating the diaphragm • If you snore loudly or have repeated awakenings followed by gasps for breath, you may be suffering from sleep apnea. • Research shows that sleep apnea may kill neurons in your brain that are critical for learning and memory. It can also lead to high blood pressure, stroke, heart attack, and accidents.