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States of Consciousness
SLEEP
Consciousness
Awareness of yourself and
your environment
• Being awake and aware
– Are automatic behaviors conscious
• Freud: what you are actively thinking about
• Which of the following is consciousness
– Sleeping
– Coma
-- Talking to your friend
-- Having Fainted
Consciousness versus Automatic
• What we are not aware of typically falls out
of our definition of consciousness
• Consciousness: when brain activity crosses a
threshold of intensity
– Chord=conscious, notes=unconscious
• Consciousness lags behind brain activity.
• Conscious processing is serial
States of Consciousness
Biological Rhythms
• Biological Rhythms are
physiological/biological patterns
• Types
– Circadian: once/day
• Examples: sleep-wake cycle, others?
– Ultradian: >once/day
• Examples: sleep cycles, others?
– Infradian: <once/day
• Examples?
Sleep Rhythms
• Circadian
• Arousal peaks during the day, dips early
after, and then drops before we go to bed
• As we age we move from night owl to
early birds
– This progresses as we age
– Starts around age 20 (bit earlier for women)
• Light is a key determinate in our sleep
rhythms
Hormones and Sleep
• Light activates light-sensitive retinal
proteinstriggers signals in the brain’s
suprachiasmatic nucleus
• The SUPER NUCLEUUUUUS causes the
pineal gland to increase or decrease
melatonin
• Brain accumulates adenosine over the
day and declines at night
– Adenosine makes us sleepy
• Artificial light delays sleep and shifts our
cycle back
How We Fall Sleep
• Hypothalamus controls body’s rhythm
– Monitors light: when dark sends signals to get
into sleep mode
• Hormones (chemical messengers)
– Melatonin: correlated with hypothalamus’s
regulated schedules and light v. dark, helps
signal us to sleep.
– Used as a therapy for insomnia
• Preserve
Why We Sleep
– Evolutionarily advantageous to sleep when
we can’t see
– Protect us from predators
– Animals that don’t need to hide and need to
graze sleep less
• Restore/Repair
– Rebuild tissues and neurons
– Grow
– Consolidate memories
Sleep Debt
• How much sleep do we need?
– Adolescents: 8ish hours
– Babies: 13-16 hrs!
– Old people: 6ish hours!
• Most adults will ideally sleep 9 hrs
• If we don’t get itsleep debt
Effects of Sleep Debt
• Decreases immune system functioning
• Increase cortisol: weight, memory, learning
• Accidents
• Accidents increase after spring forward and decrease after fall
back
• Decreased productivity and performance
• Increased likelihood for hypertension, irritability,
lower cancer-fighting immune
• Sleep affects people’s moods more than money!
• Sleep is closely correlated with personal life satisfaction
Can we pay back sleep debt?
• Bodies do keep track of sleep debt (2 weeks)
• There is a difference between short term and
long term sleep debt
• One late night can be partially paid back with
a late morning
– Improvement only lasts for six hours!
– Merely masks sleep debt
• Long term accumulation can cause sudden
sleepiness
• Becomes a physiological habit
Sleep Stages
• Occurs in a 90 minute ultradian cycle
• Each cycle has two types of sleep
– Types: REM (rapid eye movement) and NREM
(non-rapid eye movement)
• Five stages (1 stage of REM, 4 NREM)
• To monitor stages we use EEG
(electroencephalograph)
– Electrodes measure brain waves
– Compare electrical activity in different regions of
the brain
– Usually five regions are monitored
Sleep Waves
Wave
Summaries
• Alpha Waves • Delta Waves
– 7.5-14 Hz
– Awake,
relaxed
– Meditation
– .5-4 Hz
– Deep sleep
– Regenerativ
e sleep
• Beta Waves • Gamma
Waves
– 14-40 Hz
– Normal
awakened
alertness
– Higher
stress, but
pretty
common
• Theta Waves
– 4-7.5 Hz
– Sleep
(including
REM)
– >40 Hz
– Very new!
– Short bursts
of
insight/adv
anced
processing
Stages One
• Stage One
– Transition between awake and asleep
– Slowed breathing, irregular brain waves
– Individual might not even claimed to have
been asleep, they were “just resting their
eyes”
– Irregular Waves
– Characteristics: hallucinations, hypnagogic
sensations (falling, floating)
• Stage Two
Stages Two
– Characterized activity
• Burst of brain activity: spindles
• K-Complex, largest event in normal EEG activity
– Clearly asleep, but can be woken
– Sleep talking can occur
Stage Three and Four
• Stage Three
– Deep Sleep
– Presence of delta waves (high amplitude, low
frequency)
• 5-50% at stage three
• Entirely at stage four
– Hard to wake up
– End of stage four is when you see sleep walking
and bed wetting
Stage Five (REM
Sleep)
• REM=Rapid Eye Movement
• Brain waves appear almost as if you were awake
– Paradoxical Sleep: mind awake, but can’t be aroused
• Eyes move, pulse and breathing are faster, blood
flow increases
• Eyes dart under closed lids every 30 seconds
• Temporary paralysis through the brainstem
• Dreams occur
• Sexual arousal occurs (and can last after REM)
– Nightmares are an exception
Your Body Asleep
• We process information outside of
conscious awareness
– Sound of a baby versus a train
– Falling out of bed
• Motor cortex is active
– Brainstem blocks messages from the motor
cortex
– Fundamental paralyzed minus slight muscle
twitches
Dreams
• Occurs during REM sleep
• Often emotional and storylike seeming to
include almost hallucinations
• Visual and auditory areas are more active in
REM and inactive in other stages
• Eye movement does not match dream
content or watching dream
• On average people spend 100 minutes in
REM (20-25%)
– Everyone dreams!
Lucid Dreams
• Dreams where you are aware you are
dreaming
• Having some control over role in dream
• More beta waves and parietal lobe activity
Why We Dream
• Reason 1: Information Processing
– Shift and sort through the day’s experiences
– Delta sleep stabilizes memories and REM
sleep helps cement them into learning
• Correlation between grades and sleep
– More stress, more sleep
– What about dreams about nothing we have
experienced?
Why We Dream
• Reason 2: Physiological Function
– REM activity (aka dreams) provides brain
stimulation to support growth (remember your
neurons!)
– Growth hormone is secreted during delta sleep
– Babies need much more REM sleep than other
individuals
– Problem: what about meaningful dreams?
Why We Dream
• Reason 3: ActivationSynthesis
– Minds way of making
sense out of random
neural firings
– Problem: why does it
make the stories that it
does? Where does the
content come from?
Why We Dream
• Reason Four: Freud’s
Wish Fulfillment
– The Interpretation of
Dreams
– Manifest Content
• Story line of dreams
• Symbolic
– Latent Content
• What the symbols mean
• Usually sexual
– Problems
• Lack scientific evidence
Why We Dream
• Reason Five: Cognitive Development
– Part of intellectual/brain development
– Dreams move from slideshows in childhood to
movie where dreamer is an actor
– Dreams use our concepts, knowledge, and skills
Good chart on page 289
Sleep Disorders
1. Insomnia: Can’t stay or fall asleep
2. Narcolepsy: Sudden, overwhelming sleeping
3. Sleep Apnea: Snoring to the extent one stops
breathing
4. Night Terrors
5. Somnambulism: Sleep walking
6. Enuresis: Bed wetting
1: Insomnia
• Consistent problems staying or falling asleep
• People tend to overestimate how long it takes them to
fall asleep
• Solutions
–
–
–
–
–
Sleeping pills/alcohol: aggravate the problem!
Relax before bedtime
Establish routine
Use dimmer light
Avoid caffeine and rich food (glass of milk can be okay
because it provides serotonin)
– Build a consistent schedule and avoid naps
– Exercise regularly but not in the late evening
– Aim for less sleep
2: Narcolepsy
• Periodic, overwhelming sleepiness for
(usually) < 3 minutes
• Can collapse into REM sleep
• Affects about 1 in 2000 people
• There seems to be a correlation with birth
month and disorder
• Genetic
– Absence of the hypothalamic neural center that
produces hypocretin
• Temporary cessations of
breathing during sleep with
momentary awakenings
• Affects mostly overweight
men
• Symptoms: tired and irritable
during the day (spouse often
has similar symptoms)
• Affects about 1 in 20
• Solutions
– CPAP Machine (mask with air
pump to help keep airways
open)
3: Sleep
Apnea
4: Night Terrors
• High arousal and terror mid-stage four sleep
• Sufferer is usually a child and will have no
recollection of the event
• Usually outgrown
• As we spend less time in stage four we see less of
this, that’s why it is outgrown
5: Somnambulism
• Sleep walking
• Stage four disorder
– As we spend less time in stage four we see less of
this, that’s why it is outgrown
• Runs in families (much like sleep talking)
HYPNOSIS
DRUGS