Consciousness sleep & dreams-ch 4

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  • Jet Lag—mixed signals. Body adjusted to pattern, then new time, more/less light, body wants to sleep, but light keeps it awake. Sleeping late
  • Sleep is a state we do not know we are in until we leave it. Such sensations may be incorporated into memories—abducted by aliens!
  • Consciousness sleep & dreams-ch 4

    1. 1. Sleep and Dreams Chapter 4
    2. 2. <ul><li>Definition: a person’s awareness of everything that is going on around h im or her at any given moment, which is used to organize behaviro. </li></ul><ul><li>Opposite of unconscious or semi-conscious! </li></ul>
    3. 3. <ul><li>Brings varied information to the surface, enabling us to reflect and plan. </li></ul><ul><li>Enables us to exert voluntary control and to communicate our mental states to others. </li></ul><ul><li>Focuses our concentration. </li></ul>
    4. 4. <ul><li>There is much more to information processing that consciousness. </li></ul><ul><li>Much of what we process is outside our awareness. </li></ul><ul><li>Beneath the surface, unconscious information processing occurs simultaneously on many tracks. (Note parallel processing.) </li></ul>
    5. 5. <ul><li>It lags behind the brain events that evoke it. </li></ul><ul><ul><li>You consciously experience the decision to move about .2 seconds before you actually move. </li></ul></ul><ul><ul><li>But your brain waves jump about .35 seconds ahead of your conscious perception of the decision. </li></ul></ul>
    6. 6. <ul><li>Unconscious brain activity precedes conscious awareness of a simple decision preceding an action. </li></ul><ul><li>Brain wave activity jumps just 1/3 second before the person consciously decides to move. </li></ul>
    7. 7. <ul><li>2. Consciousness is relatively slow (compared to the unconscious) and has limited capacity. </li></ul><ul><li>3. Is serial in nature. We can only think one thing at a time. </li></ul><ul><li>4. Consciousness is skilled at solving novel tasks requiring focused attention. </li></ul>
    8. 8. <ul><li>Is relatively fast and can run simultaneously on multiple tracks. Parallel processing. </li></ul><ul><li>We can perform familiar tasks automatically. </li></ul>
    9. 9. <ul><li>Biological Rhythms </li></ul><ul><ul><li>Annual cycles </li></ul></ul><ul><ul><li>28 day cycles </li></ul></ul><ul><ul><li>7 day cycles? </li></ul></ul><ul><ul><li>24 hour cycles </li></ul></ul><ul><ul><li>90 minute cycles </li></ul></ul>
    10. 10. <ul><li>Regular body rhythms that occur on a 24-hour cycle. </li></ul><ul><ul><li>Body temperature </li></ul></ul><ul><ul><li>Alertness/thinking </li></ul></ul><ul><ul><li>Energy </li></ul></ul><ul><li>Ultimately controlled by the hypothalamus </li></ul>
    11. 11. <ul><li>Light tweaks the circadian clock! </li></ul><ul><li>Light activates light-sensitive retinal proteins. </li></ul><ul><li>These trigger the suprachiasmatic nucleus. </li></ul><ul><li>That structure causes the pineal gland to increase or decrease melatonin. </li></ul>
    12. 12. <ul><li>Production peaks in the evening hours. </li></ul><ul><li>More light triggers the suprachiasmatic nucleus to signal the pineal gland to decrease melatonin production. </li></ul><ul><li>Less light stimulates more melatonin production, which helps aids sleepiness! </li></ul><ul><li>BUT, melatonin does not directly control sleep so other factors also affect sleep. </li></ul>
    13. 13. <ul><li>The chemical adenosine accumulates in our systems throughout the day, also contributing to sleepiness. </li></ul><ul><li>It dissipates while we sleep so we can wake up refreshed in the morning. </li></ul><ul><li>Caffeine can block adenosine’s </li></ul><ul><li>activity, so we can stay up longer. </li></ul>
    14. 14. <ul><li>Serotonin also seems to play a role in sleepiness. More serotonin seems to produce increases sleepiness. </li></ul><ul><li>Body Temperature: as body temperature goes down, you feel sleepy. </li></ul><ul><li>Not sure what roles serotonin and body temperature play; the research is correlational. </li></ul>
    15. 15. <ul><li>Jet lag? </li></ul><ul><li>Sleeping late on the weekend mornings?? </li></ul><ul><li>The effects of artificial light? </li></ul>
    16. 16. <ul><li>Sleep: periodic, natural, reversible loss of consciousness—as distinct from unconsciousness resulting from a coma general anesthesia, or hibernation. </li></ul><ul><li>The brain is still active while we sleep. About every 90 minutes we pass through a cycle of 5 distinct stages. </li></ul>
    17. 17. <ul><li>Just before sleep, Alpha waves show you awake and relaxed </li></ul><ul><li>Stage 1. Slowed breathing and irregular brainwaves. 5-10 minutes. You may experience fantastic images, resembling hallucinations, or a sense of falling/floating. </li></ul>
    18. 19. <ul><li>More deeply relaxed stage characterized by the periodic appearance of sleep spindles—bursts of rapid rhythmic brainwave activity. Lasts about 20 minutes. </li></ul><ul><li>Tensing and relaxing of muscles. </li></ul><ul><li>Sleeptalking can occur in this state or any other stage. </li></ul>
    19. 20. <ul><li>For a few minutes you go through this transition phase. </li></ul><ul><li>The brain begins to emit large slow delta waves. </li></ul>
    20. 21. <ul><li>More large, slow delta waves. </li></ul><ul><li>Stages 3-4 last about 30 minutes. </li></ul><ul><li>At the end of stage 4, children may wet the bed or begin walking in their sleep. </li></ul>
    21. 22. <ul><li>The auditory cortex will respond to sound stimuli. You can ignore common street sounds but wake up to your name. </li></ul><ul><li>You can sleep with babies (or pets) without rolling over them. (notable exception is when someone has used drugs.) </li></ul>
    22. 23. <ul><li>Rapid Eye Movement sleep, a recurring sleep stage during which vivid dreams commonly occur. Cannot be easily awakened. </li></ul><ul><li>Also known as paradoxical sleep because the muscles are relaxed but other body systems are active. </li></ul><ul><li>The inability to move in REM sleep is called REM paralysis . </li></ul>
    23. 24. <ul><li>As the night goes on, Stage 4 sleeps gets shorter and REM sleep gets progressively longer. </li></ul><ul><li>PET Scans show the visual and auditory cortexes are relatively active during REM sleep, but inactive during other stages. </li></ul><ul><li>The motor cortex is active, too, but the brain stem blocks its messages and muscles stay relaxed. </li></ul><ul><li>20-25% of our average night’s sleep. </li></ul>
    24. 25. <ul><li>REM sleep is characterized by dreaming, often emotional, story-like, more richly hallucinatory. </li></ul><ul><li>37% of people report rarely or never having dreams! They just don’t remember them. </li></ul>
    25. 26. <ul><li>REM sleep deprivation studies showed increased anxiety, irritability, and difficulty concentrating, as well as an increase in appetite. </li></ul><ul><li>Other researchers observed participants experiencing confusion, suspicion, withdrawal, and being “less well integrated and less interpersonally effective”.  </li></ul>
    26. 27. <ul><li>If deprived of REM sleep, people will actually return faster to REM sleep after going back to bed. </li></ul><ul><li>REM rebound : The tendency for a person (or animal) deprived of REM sleep to spend an increased proportion of sleeping time in REM sleep. </li></ul>
    27. 28. <ul><li>Newborns sleep about 2/3’s of the day! </li></ul><ul><li>Possible genetic factor in how much we need. </li></ul><ul><li>Teenagers typically need 8-9 hours a day. (Typically get less than 7!) </li></ul><ul><li>Adults need 6-9 hours a day. </li></ul><ul><li>People in industrial countries sleep less. </li></ul>
    28. 29. <ul><li>Some believe 80% of students are dangerously sleep deprived. </li></ul><ul><ul><li>Causes difficulty studying. </li></ul></ul><ul><ul><li>At high risk for accidents. </li></ul></ul><ul><ul><li>Tendency to make mistakes. </li></ul></ul><ul><ul><li>Irritability </li></ul></ul><ul><ul><li>General fatigue increases. </li></ul></ul>
    29. 30. <ul><li>Slowed reaction times and increased errors on visual tasks. </li></ul><ul><li>Driving and piloting errors increase. </li></ul><ul><li>Suppression of the immune system. </li></ul><ul><li>Alters metabolic and hormonal functioning in ways that mimic aging, connected to obesity, hypertension and memory impairment. </li></ul><ul><li>Irritability, slowed performance; impaired creativity, concentration, and communication. (ADHD?) </li></ul>
    30. 32. <ul><li>Sleep deprivation might be disrupting hormones that regulate glucose metabolism and appetite. </li></ul><ul><li>Leptin, known as the “fullness hormone,” goes down with sleep deprivation. </li></ul><ul><li>Ghrelin, known as the “hunger hormone,” tends to be higher with sleep deprivation. </li></ul>
    31. 33. <ul><li>Sleep debt is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental and/or physical fatigue. There is debate in the scientific community over the specifics of sleep debt. </li></ul>
    32. 34. <ul><li>Current research indicates that the body’s maximum sleep debt is under 20 hours, no matter how many consecutive nights you’ve lost sleep. </li></ul><ul><li>It seems that sleep debt can only be paid off with minimum payments of 1-2 hours at a time. (i.e. not sleeping the whole the weekend!) </li></ul>
    33. 36. <ul><li>1. The Adaptive Theory of Sleep. </li></ul><ul><li>Evolutionary psychology points to man’s vulnerability at night against predators. Sleeping inside at night increased man’s survival! </li></ul>
    34. 37. <ul><li>2. The Restorative Theory of Sleep </li></ul><ul><li>The theory of sleep proposing that sleep is necessary to the physical health of the body and serves to replenish chemicals and repair cellular damage. </li></ul><ul><li>Replenishes chemicals; cellular damage repaired. </li></ul><ul><li>Body growth—growth hormones from pituitary gland secreted during sleep. </li></ul>
    35. 38. <ul><li>In addition, it helps our memory. Sleep restores and rebuilds our fading memories of the day’s experiences/learning. </li></ul>
    36. 39. <ul><li>Insomnia —persistent problems in falling or staying asleep. </li></ul><ul><ul><li>10-15% of adults complain of insomnia. </li></ul></ul><ul><ul><li>Practice better sleep hygiene!—see </li></ul></ul><ul><ul><li>page 147 in the book. </li></ul></ul>
    37. 40. <ul><li>A sleep disorder characterized by uncontrollable sleep attacks, periodic, overwhelming sleepiness. May lapse directly into REM sleep. </li></ul><ul><ul><li>Cause: seems to be a relative absence of a hypothalamic neural center that produces hypocretin, an alerting neurotransmitter. </li></ul></ul>
    38. 41. <ul><li>A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings. </li></ul><ul><ul><li>The person stops breathing; decreased blood oxygen arouses them to awaken and snort in air for a few seconds, then go back to sleep! </li></ul></ul><ul><ul><li>This can repeat 400 times a night. </li></ul></ul><ul><ul><li>Signs: tired and irritable, high blood pressure, snores at night, overweight. </li></ul></ul>
    39. 42. <ul><li>4. A sleep disorder characterized by high arousal and an appearance of being terrified. </li></ul><ul><ul><li>Unlike nightmares, night terrors occur during Stage 4 sleep, within 2-3 hrs of falling asleep and are seldom remembered. </li></ul></ul><ul><ul><li>Targets mostly children. They may sit up & walk around, talk incoherently, and appear terrified. They seldom wake up fully and don’t really remember in the morning! </li></ul></ul>
    40. 43. <ul><li>Another stage 4 sleep disorder. </li></ul><ul><ul><li>Mostly in children, rare in adults. </li></ul></ul>
    41. 44. <ul><li>A sleep disorder that occurs somewhere between wakefulness and Stage 1. </li></ul><ul><ul><li>The person feels awake, but experiences paralysis and fear. </li></ul></ul>
    42. 45. <ul><li>A rare disorder in which the mechanism that blocks the movement of the voluntary muscles fails, allowing the person to thrash around and even get up and act out nightmares. </li></ul>
    43. 46. <ul><li>1. Freud’s theories. </li></ul><ul><ul><li>To satisfy our own wishes. Freud believed dreams allow unacceptable wishes to be released from the psyche! </li></ul></ul><ul><ul><li>Manifest content: the actual content, what you remember </li></ul></ul><ul><ul><li>Latent content: the true meaning of the dream, which is hidden. </li></ul></ul>
    44. 47. <ul><li>2. Activation-Synthesis Hypothesis </li></ul><ul><li>Explanation that states that dreams are created by the higher centers of the cortex to explain the activation by the brain stem of cortical cells during REM sleep periods. </li></ul><ul><li>Basically, the brain tries to make sense of neural static. Neural activity is random but the higher brain centers try to make it cohesive, making a dream. </li></ul>
    45. 48. <ul><li>Hobson and colleagues upgraded the activation-synthesis hypothesis to: </li></ul><ul><li>The activation-information-mode model (AIM). Information that is accessed during waking hours can have an influence on the synthesis of dreams. As the brain makes up a dream, it uses meaningful bits of recent experience. </li></ul>

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