Sleep

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Sleep Body Rhythms
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What is Consciousness?

• Consciousness Your immediate awareness of
  thoughts, sensations, memories, and the world
  around you. Experience of this tends to blend
  together.
• William James described consciousness as a
  "stream" or "river" that is always changing but
  unified and unbroken.
• Consciousness first studied through introspection
  (verbal self-reports) and later rejected in favor
  of studying only observable overt behavior.
• 1950's brought a new desire to study
  consciousness for two reasons.
• Complete understanding of behavior had to
  consider the role of conscious mental processes.
• Psychologists had created more objective ways to
  study consciousness.

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Body Rhythms

• Natural variations we experience daily in our
  consciousness as a part of our sleep-wake cycle.
  
• Most people experience at least two peaks in
  mental alertness
• morning around 900 or 1000 and
• 800 or 900 PM.
• Slumps in your mental alertness occur at about
  300 PM and 300 AM.

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Biological Rhythms

• Periodic physiological fluctuations
• Can affect physiological functioning
• Fall into three main categories
• Circadian Rhythms
• Ultradian Rhythms
• Infradian Rhythms

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Circadian Rhythms

• Any rhythmic change that occurs approximately
  once in a 24-hour cycle
• body temperature
• cortisol secretion
• sleep and wakefulness
• In the absence of time cues, the cycle period
  will become somewhat longer than 24 hours
• Many of your processes like blood pressure,
  hormones, pain sensitivity along with sleep and
  wake cycles vary over the day

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Sleep and Circadian Rhythms

• Play Sleep and Circadian Rhythms (609) Module
  13 from The Brain Teaching Modules (2nd
  edition).
• Intro to Circadian Rhythms Cave Experiment

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(No Transcript)
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The Bodys Clock

• Suprachiasmatic nucleus (SCN)cluster of neurons
  in the hypothalamus that governs the timing of
  circadian rhythms
• Melatoninhormone of the pineal gland that
  produces sleepiness

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The Bodys Clock How it works

• Special photoreceptors in the retina regulate the
  effects of light on the bodys circadian rhythms
• In response to morning light, signals from these
  special photoreceptors are relayed via the optic
  nerve to the suprachiasmatic nucleus.
• In turn, the suprachiasmatic nucleus causes the
  pineal gland to reduce the production of
  melatonin, a hormone that causes sleepiness.
• As blood levels of melatonin decrease, mental
  alertness increases.
• Daily exposure to bright light, especially
  sunlight, helps keep the bodys circadian rhythms
  synchronized and operating on a 24-hour schedule.

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How Melatonin works

• More melatonin sleepy and reduce activity
  levels (between 1-3 AM)
• Less Melatonin more alert and active. Body
  stops produced melatonin shortly before sunrise
  and sunlight suppresses melatonin levels
  throughout the day
• Jet Lag Since your body is still operating on
  the time you left from, your melatonin levels
  will be off causing a disruption in your
  circadian rhythms and making you mentally
  fatigued, depressed, irritable and have problems
  sleeping.
• Night workers will always have some problems due
  to sunlight resetting their biological clock.

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Biological Rhythms

• Play Can You Beat Jet Lag? (644) Segment 15
  from Scientific American Frontiers Video
  Collection for Introductory Psychology (2nd
  edition).
• How light is used by the body to reset your
  biological clock.

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Circadian Rhythms

• Play Circadian Rhythms (358) Segment 9 from
  Psychology The Human Experience.
• Lack of Sleep (on-call workers) Job Performance
• What are the down times during the day?

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Ultradian Rhythms

• Biological rhythms that occur more than once each
  day
• Example Cycling through the stages of sleep
  throughout the night

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Infradian Rhythms

• Biological rhythms that occur once a month or
  once a season
• Example Womens menstrual cycle or a bears
  winter hibernation

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Biorhythms vs. Circadian Rhythms

• Biorhythms pseudoscience that says people have
  three natural rhythms that follow cycles.
  23-day physical cycle, 28-day emotional, and
  33-day intellectual functioning. These are
  determined by the date of your birth.
• Chronobiology study of biological rhythms over
  time. Studies have not scientifically proven
  that biorhythms play a role in certain events
  (pg. 141).

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A Sleep SurveyMost people will spend about 22
years of their life sleeping. How much are you
spending?

• 1. To the nearest quarter hour, what is your
  bedtime on a school night?
• 2. On the average, how many minutes does it take
  you to fall asleep after going to bed?
• 3. To the nearest quarter hour, how many hours of
  sleep do you get on an average school night?

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A Sleep Survey

• 4. In an average night, how many times do you
  wake up?
• 5. On a scale of 1 to 10, with one being poor and
  10 being wonderful, rate the quality of your
  sleep on a typical night.
• 6. On a scale of 1 to 10, with one being easy and
  10 being difficult, how hard is it for you to
  wake up in the morning?

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A Sleep Survey

• 7. In a typical 7-day week, how many naps do you
  take?
• 8. When are you generally most awake and alert?
• -Morning
• -Afternoon
• -Evening
• -Night

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A Sleep Survey

• 9. After a typical nights sleep, how many dreams
  do you recall?
• 10. Which term most accurately describes your
  typical dream?
• -Pleasant
• -Unpleasant
• -Neutral

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Sleep and Sleep Deficit
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Sleep Deprivation Effects

• Hurts performance on simple, boring tasks more
  than challenging ones
• Decreases efficiency of immune system functioning
• Raises the levels of stress hormone cortisol
  which is linked to damage of the brain cells
  responsible for learning memory
• Safety and accident issues
• Contributes to hypertension, impaired
  concentration, irritability, premature aging,
  etc.
• After one night of sleep deprivation, people have
  episodes of sleep lasting a few seconds called
  microsleeps
• See NBC Report on Sleeplessness in America (2
  min)
• See NBC Report on Sleep Study (3 min)

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Sleep Deprivation(National Transportation Safety
Board, 1995)
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Why We Sleep

• Most people need 8-8.5 hours of sleep to function
  but most Americans sleep 7-7.5 hours. Almost 1/3
  of Americans get less than 6 hours. 74 women
  sleep less than 8 hours a night.
• Most teens need 9 hours and 15 minutes of sleep a
  night. Average teenager's biological clock
  doesn't prepare them to awaken until 8 or 9 AM.
  This can interfere with memory and learning.
  Students with most sleep did better on grades and
  exams.
• Getting less sleep than you need can cause
  harmful changes in metabolic and endocrine
  functioning. Study found after only one week of
  sleep restriction of 4 hours of sleep a night,
  subjects had glucose levels that were no longer
  normal.
• REM deprivation will cause subjects to have REM
  rebound in which they spend more time in REM
  sleep in an effort "catch up."
• Stage 3 4 NREM deprivation people will have
  NREM rebound and "catch-up" by spending more time
  in these stages.

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Functions of Sleep

• Restoration theorybody wears out during the day
  and sleep is necessary to put it back in shape
• NREM sleep sees increases in the release of
  growth hormone, testosterone, prolactin.
• REM sleep plays a role in rate of brain
  development that occurs in the early stages of
  the lifespan.
• Adaptive theorysleep emerged in evolution to
  preserve energy and protect during the time of
  day when there is little value and considerable
  danger
• Animals with few natural predators sleep the most
  while animals with many sleep less.
• Hibernation occurs during the time of year most
  hazardous to the animal.

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Hypothalamus

• Sleep control center in the brain
• Monitors changes in light or dark in the
  environment
• Changes levels of hormones in the body

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Melatonin

• A hormone that helps regulate daily biological
  rhythms
• Linked to the sleep-wake cycle
• Melatonin level increases during the night and
  decreases with exposure to morning light

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IMPROVING SLEEP MENTAL ALERTNESS

• Dealing with Morning Brain Fog or Sleep Inertia
• Staying in bed until the last possible moment
  will only intensify disorientation as you hustle
  to work.
• Best way to treat it is to allow for more passage
  of time.
• Set your alarm 15 minutes earlier and make it so
  you have to get up to turn it off.
• Drink something with caffeine and sit near
  sunlight.
• Read something to get your brain engaged.

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Coping with the Night Shift

• Avoid frequent shift changes
• Easier to lengthen your days than shorten them.
  Progress morning to evening to night shifts.
• If working at night use bright lights especially
  early on in the shift to adjust your circadian
  rhythm.
• Take melatonin in the daytime to help you sleep.

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Sleep Deprivation Studies

• Play Catching Catnaps (1145) Segment 13 from
  Scientific American Frontiers Video Collection
  for Introductory Psychology (2nd edition).
• Which stages of sleep are most important?
• Can a person survive on naps alone?
• How does lack of sleep or bonus sleep affect
  mood?

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Improving the Quality of Your Sleep

• Avoid going to sleep in the "forbidden zone" of
  wakefulness that usually occurs between 8-10PM.
• Don't drink or eat caffeine-containing drinks or
  foods. See table 4.7 on pg. 175 for common
  sources of caffeine.
• Don't go to bed very hungry or full
• Moderate exercise during the day helps but not
  just before sleep.
• Raise your core body temperature with a warm bath
  or shower.
• Develop a consistent bedtime routine.
• Avoid depressant drugs which promote sleep but
  reduce REM sleep.
• Write down concerns and why you plan to do about
  them the next day or redirect your thoughts to
  something relaxing to deal with stress.

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Sleep Stages, REM, and DreamingThe Stages of
Sleep
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Electroencephalograph (EEG)

• A machine that amplifies and records waves of
  electrical activity that sweep across the brains
  surface
• Electrodes are placed on the persons scalp to
  measure the waves
• Used as a means to measure the stages of sleep

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Electroencephalogram (EEG)

• Electrodes placed on the scalp provide a gross
  record of the electrical activity of the brain
• EEG recordings are a rough index of psychological
  states

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EEG Waves of Wakefulness

• Awake and attentive low amplitude, fast,
  irregular beta waves

• Awake, but non-attentive large, regular alpha
  waves

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Onset of Sleep

• Awake alert, your brain produces small, fast
  brain waves called beta waves.
• As you lay down and close your eyes, your brain's
  electrical activity gradually gears down
  generating slightly larger and slower alpha brain
  waves.
• During drowsy, presleep stage you may experience
  vivid sensory phenomena called hypnagogic
  hallucinations.
• Most common hallucination is that of falling
  which can produce a myoclonic jerk or sleep
  starts involuntary muscle spasm of the whole
  body that jolts the person completely awake.

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Stage 1 Sleep

• Breathing is slowed.
• Brain waves become irregular.
• It is easy to wake the person, who will insist
  they are not asleep.
• Lasts only a few minutes.
• Familiar sounds fade away but your can regain
  alertness if something interrupts you.
• Some imagery is common although no very strange
  or vivid.

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Stages of Sleep
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Stage 1
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Stage 1
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Stage 2 Sleep

• Brain wave cycle slows.
• Appearance of sleep spindles or brief bursts of
  brain activity and K complexes or large
  high-voltage spikes of brain activity that
  periodically occur.
• Brain activity slows considerably and breathing
  becomes rhythmic.
• Slight muscle twitches occur.
• Brain waves begin to slowly switch from Theta
  waves to slower and larger delta waves.

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Stage 2
K Complex
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Stages 3 and 4 SleepSlow Wave Sleep

• Increase in delta waves (large and slow waves per
  second) 20 Stage 3. More than 50 Stage 4.
• First time through stage 4 is about 30 minutes
  and is where one gets rejuvenated
• During the first stage 4 of sleep, heart rate,
  blood pressure and breathing drop to their lowest
  levels and it is very hard to wake up.
• Sleepwalking occurs here.
• People can "wake up" during stage 4 and do a
  simple task and not remember it.

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Stage 3
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Stage 4
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Stages of Sleep1-4Quick Review

• Sleep stage 1 brief transition stage when first
  falling asleep
• Stages 2 through 4 (slow-wave sleep)
  successively deeper stages of sleep
• Characterized by an increasing percentage of
  slow, irregular, high-amplitude delta waves

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REM Sleep

• Stages 1 - 4 considered N-REM (non-REM sleep)
• Rapid eye movement (REM Sleep) as eyes move
  quickly back and forth
• Most dreaming occurs in REM sleep but muscle
  activity is suppressed to keep you acting them
  out.
• If denied REM sleep and then allowed a person
  will experience REM Rebound and will increase
  their time in REM by 50. Catching Up on REM
  sleep.

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REM Sleep
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REM Paradoxical Sleep

• During REM sleep brain wave patterns are similar
  to when a person is awake
• Visual and motor neurons in the brain fire like
  they do when you are awake.
• Eyes dart back and forth and heart rate, blood
  pressure and respirations fluctuate up and down.
• REM sleep is sometimes called paradoxical sleep
  as ones physiology is close to that of being
  awake but the brainstem blocks all muscle
  movement
• The first REM cycle lasts for 5 to 15 minutes.

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Stages of Sleep

• Upon reaching stage 4 and after about 80 to 100
  minutes of total sleep time, sleep lightens,
  returns through stages 3 and 2
• REM sleep emerges, characterized by EEG patterns
  that resemble beta waves of alert wakefulness
• muscles most relaxed
• rapid eye movements occur
• dreams occur
• Four or five sleep cycles occur in a typical
  nights sleep less time is spent in slow-wave,
  more is spent in REM

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Typical Nights Sleep
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(No Transcript)
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Stage 4/REM Changes
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Sleep Changes through Life
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Sleep

• Play Sleep Brain Functions (1112) Module 14
  from The Brain Teaching Modules (2nd edition).
• Review of the stages of sleep.
• What happens to animals that are not allowed to
  sleep?
• What defines normal abnormal sleep?
• Categories of Sleep Disorders

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Dream Facts

• 25 of your nights sleep or 2 hours is spent
  dreaming.
• Sleep Thinking Vague, uncreative, bland
  thoughts about real-life events that take place
  in NREM. Occur more than dreams.
• Dreams have 5 basic characteristics
• Emotions can be intense
• Content Organization are usually illogical
• Sensations are sometimes bizarre
• Bizarre details are uncritically accepted
• Dream images are difficult to remember
• Dreams occur in both NREM and REM sleep however
  they are more frequent and last longer in REM.
• People usually have 4-5 episodes of dreaming a
  night. Dreams happen in real time.

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Brain During REM Sleep

• PET scans reveal that brain activity is much
  different in REM sleep than when youre awake.
• Frontal Lobe and Primary Visual Cortex (registers
  visual info from retinas) are essentially shut
  down during REM meaning you are shut out from the
  external world and rational thought so you accept
  your dreams no matter how bizarre they are.
• Amygdala hippocampus of the limbic system which
  deal with emotion and memory are highly active as
  are the brains visual areas.

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What do we Dream About?

• Most dreams are about everyday life.
• Some themes are found across cultures. (See
  Common Dream Themes Table 4.3 pf. 155)
• Aggression is more common than friendliness in
  dreams.
• Environmental cues during dreaming may be
  incorporated into the dream.
• What you really want to know about dreams? (Read
  more - In Focus 4.4, pg. 157)

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• Why dont remember our dreams?
• Areas of the brain used in forming memories
  (frontal lobe) are shut down during REM sleep and
  neurotransmitters that are used to make memories
  are greatly reduced.
• More likely to remember a dream if you wake up
  during it. Visual encoders tend to be better at
  remembering dreams. Vivid dreams are more likely
  to be recalled.
• Distractions when you awaken can cause problems
  with remembering dreams.
• Brain seems programmed to forget most of what
  occurs during sleep.

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Types of Dreams

• True dreamvivid, detailed dreams consisting of
  sensory and motor sensations experienced during
  REM
• Sleep thoughtlacks vivid sensory and motor
  sensations, is more similar to daytime thinking,
  and occurs during slow-wave sleep
• Lucid dreaming

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Physiological Function Theory

• Neural activity during REM sleep provides
  periodic stimulation of the brain.

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Psychoanalytic Interpretation

• Sigmund Freud Dreams are the fulfillment of
  wishes. Unacceptable thoughts of sex
  aggression are repressed when you are conscious
  but come forth when you are asleep in the form of
  dreams.
• Dreams were the royal road to the
  unconsciousness and a safety valve that
  allowed for the release of unconscious and
  unacceptable urges.
• Two components of Dreams
• Manifest Content dream images themselves
• Latent Content Disguised psychological meaning
  of the dream.
• Research does not support his theories.

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Activation Synthesis Model

• Brain activity during sleep produces dream images
  (activation) which are combined by the brain into
  a dream story (synthesis).
• Meaning is to be found by analyzing the way the
  dreamer makes sense of the progression of chaotic
  dream images.
• OR, to put it another way
• Activation of brain stem area (Pons) arouse other
  brain areas including visual and auditory and
  limbic systems.
• Brain responds to these internally created
  signals and assigns them meaning using memories,
  emotions and sensations.

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Activation-Synthesis Theory

• Dreams are the minds attempt to make sense of
  random neural firings in the brain as one sleeps.

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Information-Processing Theory

• Dreams serve an important memory- related
  function by sorting and sifting through the days
  experiences
• Research suggests REM sleep helps memory storage.

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REM Memory Consolidation

• Memory Consolidation converting new memories
  into a long-term, relatively permanent form.
• REM seems to help with procedural memories
  (skills like riding a bike).
• REM seems to improve performance on learned
  tasks.
• Brain areas activated during training on a task
  actually are reactivated during REM sleep perhaps
  stabilizing the neural connections formed in the
  recent training experience.

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Dream Research

• Play Whats in a Dream? (1300) Segment 14
  from Scientific American Frontiers Video
  Collection for Introductory Psychology (2nd
  edition).
• Dream research with Alan Alda.
• What happens biologically when we dream during
  REM sleep?
• Where do stories of our dreams come from?
• How brains try to make sense of nonsense.
• What kind of tasks are more difficult if you have
  random sleep loss?
• Can dreaming help us learn?

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Sleep Disorders and Sleep Problems
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Individual Differences in Sleep Drive

• Some individuals need more and some less than the
  typical 8 hours per night
• Nonsomniacssleep far less than most, but do not
  feel tired during the day
• Insomniacshas a normal desire for sleep, but is
  unable to and feels tired during the day

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Sleep Disorders Quick List

• Insomniainability to fall asleep or stay asleep
• REM sleep disordersleeper acts out his or her
  dreams
• Night terrorssudden arousal from sleep and
  intense fear accompanied by physiological
  reactions (e.g., rapid heart rate, perspiration)
  that occur during slow-wave sleep
• Narcolepsyoverpowering urge to fall asleep that
  may occur while talking or standing up
• Sleep apneafailure to breathe when asleep See
  clip of it here.

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Insomnia

• Recurring problems falling asleep or staying
  asleep
• Sleeping pills tend to inhibit or suppress REM
  sleep worsen the problem
• Alcohol suppresses REM sleep also worsens the
  problem
• Studies show most people overestimate how long it
  took them to get to sleep

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Sleep Apnea

• A sleep disorder characterized by temporary
  cessations of breathing during sleep and
  consequent momentary reawakenings.
• Tend to be loud snorers
• Continuous Positive Airway Pressure machine

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Narcolepsy

• A sleep disorder characterized by uncontrollable
  sleep attacks
• Person goes directly into REM sleep
• Nervous system getting aroused tends to trigger
  the sleep attack
• Narcolepsy has a genetic link and runs in some
  breeds of dogs.
• Rusty the Narcoleptic Dog (Click to View)
• Other Dogs with Narcolepsy (Click to View)
• Teenagers Living with Narcolepsy (Click to View)

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Somnambulism

• Formal name for sleepwalking
• Starts in the deep stages of N-REM sleep
• Person can walk or talk but remembers nothing of
  the experience
• Sleep Walking has been linked to Sleep
  Deprivation. (NBC Report 2 min.)

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Night Terrors

• Sleep disorder characterized by high arousal and
  appearance of being terrified
• Happens during stage 4 sleep mostly children
• The children seldom remember the event.

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Other Sleep Disorders

• Bruxism teeth grinding
• Enuresis bed wetting
• Myoclonus sudden jerk of a body part occurring
  during stage 1 sleep
• Everyone has occasional episodes of myoclonus