Body Rhythms

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Body Rhythms Sleep
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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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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.
  Some major health issues could occur See NBC
  Nightly News Report

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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
• Lack of Sleep is a serious problem in America
  Sleepless in America NBC Report (2 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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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 none very strange
  or vivid.

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Stages of Sleep
Observe Stage Alpha waves
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Stage 1
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Stage 1
Observe Stage 1 Sleep waves
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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
Observe Stage 2 Sleep waves
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
Observe Stage 3 Sleep waves
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Stage 4
Observe Stage 4 Sleep waves
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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
• Can you tell when a persons EEG shifts from one
  stage to the next? Try it yourself!

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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
Observe REM Sleep waves
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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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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 preview of sleep
  disorders.
• What happens to animals that are not allowed to
  sleep?
• What defines normal abnormal sleep?
• Categories of Sleep Disorders